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Message-ID: <20080714135433.GA9609@elte.hu>
Date: Mon, 14 Jul 2008 15:54:33 +0200
From: Ingo Molnar <mingo@...e.hu>
To: Linus Torvalds <torvalds@...ux-foundation.org>
Cc: linux-kernel@...r.kernel.org,
Peter Zijlstra <a.p.zijlstra@...llo.nl>,
Andrew Morton <akpm@...ux-foundation.org>
Subject: [git pull] scheduler changes for v2.6.27
Linus,
Please pull the latest scheduler git tree from:
git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip.git sched/for-linus
Thanks,
Ingo
------------------>
Ankita Garg (1):
sched: fix accounting in task delay accounting & migration
Arjan van de Ven (1):
sched: print module list in the "scheduling while atomic" warning
David Rientjes (1):
sched: prevent bound kthreads from changing cpus_allowed
Dhaval Giani (2):
sched: add comments for ifdefs in sched.c
sched: make sched_{rt,fair}.c ifdefs more readable
Dmitry Adamushko (2):
sched: check for SD_SERIALIZE atomically in rebalance_domains()
sched: rework of "prioritize non-migratable tasks over migratable ones"
Gautham R Shenoy (2):
sched: update the sched-domains debug documentation
sched: print the sd->level in sched_domain_debug code
Gregory Haskins (7):
sched: prioritize non-migratable tasks over migratable ones
sched: use a 2-d bitmap for searching lowest-pri CPU
sched: fix SCHED_OTHER balance iterator to include all tasks
sched: fix cpupri hotplug support
sched: fix cpupri priocount
sched: terminate newidle balancing once at least one task has moved over
sched: add avg-overlap support to RT tasks
Hiroshi Shimamoto (1):
sched: fix typo in Documentation/scheduler/sched-rt-group.txt
Ingo Molnar (5):
namespacecheck: more sched.c fixes
sched: fix cpuprio build bug
sched: export cpu_clock
sched: sched_clock_cpu() based cpu_clock(), lockdep fix
sched: build fix
Max Krasnyansky (2):
sched: CPU hotplug events must not destroy scheduler domains created by the cpusets
sched: Move cpu masks from kernel/sched.c into kernel/cpu.c
Mike Galbraith (2):
sched: make !hrtick faster
sched: trivial sched_features cleanup
Paul Mundt (1):
sched: kill off dead cfs_rq_set_shares()
Peter Zijlstra (34):
sched: fix hotplug cpus on ia64
sched: debug: add some rt debug output
sched: rt: fix SMP bandwidth balancing for throttled groups
sched: rt: move some code around
sched: rt: fix the bandwidth contraint computations
sched: rt: dont stop the period timer when there are tasks wanting to run
sched: clean up some unused variables
sched: revert the revert of: weight calculations
sched: fix calc_delta_asym()
sched: fix calc_delta_asym, #2
sched: revert revert of: fair-group: SMP-nice for group scheduling
sched: sched_clock_cpu() based cpu_clock()
sched: fix wakeup granularity and buddy granularity
sched: add full schedstats to /proc/sched_debug
sched: fix sched_domain aggregation
sched: update aggregate when holding the RQs
sched: dont micro manage share losses
sched: no need to aggregate task_weight
sched: simplify the group load balancer
sched: fix newidle smp group balancing
sched: fix sched_balance_self() smp group balancing
sched: persistent average load per task
sched: hierarchical load vs affine wakeups
sched: hierarchical load vs find_busiest_group
sched: fix load scaling in group balancing
sched: fix task_h_load()
sched: remove prio preference from balance decisions
sched: optimize effective_load()
sched: disable source/target_load bias
sched: fix shares boost logic
sched: update shares on wakeup
sched: correct wakeup weight calculations
sched: incremental effective_load()
sched: bias effective_load() error towards failing wake_affine().
Rabin Vincent (1):
sched: fix defined-but-unused warning
Richard Kennedy (1):
sched: reorder task_struct to reduce padding on 64bit builds
Srivatsa Vaddagiri (2):
sched: kill task_group balancing
sched: fix mult overflow
Steven Rostedt (7):
sched_clock: record from last tick
sched_clock: widen the max and min time
sched_clock: stop maximum check on NO HZ
sched_clock: fix calculation of other CPU
sched_clock: only update deltas with local reads.
sched_clock: record TSC after gtod
sched_clock: and multiplier for TSC to gtod drift
Thomas Gleixner (3):
namespacecheck: fixes in kernel/sched.c
sched: fix the cpuprio count really
sched: move weighted_cpuload into #ifdef CONFIG_SMP section
Vegard Nossum (1):
sched: fix warning
Documentation/scheduler/sched-domains.txt | 7 +-
Documentation/scheduler/sched-rt-group.txt | 4 +-
include/linux/sched.h | 59 ++--
kernel/Makefile | 5 +-
kernel/cpu.c | 24 +
kernel/cpuset.c | 14 +-
kernel/kthread.c | 1 +
kernel/sched.c | 723 +++++++++++++++++++---------
kernel/sched_clock.c | 137 +++++-
kernel/sched_cpupri.c | 174 +++++++
kernel/sched_cpupri.h | 36 ++
kernel/sched_debug.c | 64 +++-
kernel/sched_fair.c | 413 +++++++++++-----
kernel/sched_features.h | 7 +-
kernel/sched_rt.c | 405 ++++++++++------
kernel/sched_stats.h | 42 ++-
kernel/sysctl.c | 8 +
kernel/time/tick-sched.c | 2 +
18 files changed, 1555 insertions(+), 570 deletions(-)
create mode 100644 kernel/sched_cpupri.c
create mode 100644 kernel/sched_cpupri.h
diff --git a/Documentation/scheduler/sched-domains.txt b/Documentation/scheduler/sched-domains.txt
index a9e990a..373ceac 100644
--- a/Documentation/scheduler/sched-domains.txt
+++ b/Documentation/scheduler/sched-domains.txt
@@ -61,10 +61,7 @@ builder by #define'ing ARCH_HASH_SCHED_DOMAIN, and exporting your
arch_init_sched_domains function. This function will attach domains to all
CPUs using cpu_attach_domain.
-Implementors should change the line
-#undef SCHED_DOMAIN_DEBUG
-to
-#define SCHED_DOMAIN_DEBUG
-in kernel/sched.c as this enables an error checking parse of the sched domains
+The sched-domains debugging infrastructure can be enabled by enabling
+CONFIG_SCHED_DEBUG. This enables an error checking parse of the sched domains
which should catch most possible errors (described above). It also prints out
the domain structure in a visual format.
diff --git a/Documentation/scheduler/sched-rt-group.txt b/Documentation/scheduler/sched-rt-group.txt
index 14f901f..3ef339f 100644
--- a/Documentation/scheduler/sched-rt-group.txt
+++ b/Documentation/scheduler/sched-rt-group.txt
@@ -51,9 +51,9 @@ needs only about 3% CPU time to do so, it can do with a 0.03 * 0.005s =
0.00015s. So this group can be scheduled with a period of 0.005s and a run time
of 0.00015s.
-The remaining CPU time will be used for user input and other tass. Because
+The remaining CPU time will be used for user input and other tasks. Because
realtime tasks have explicitly allocated the CPU time they need to perform
-their tasks, buffer underruns in the graphocs or audio can be eliminated.
+their tasks, buffer underruns in the graphics or audio can be eliminated.
NOTE: the above example is not fully implemented as of yet (2.6.25). We still
lack an EDF scheduler to make non-uniform periods usable.
diff --git a/include/linux/sched.h b/include/linux/sched.h
index c5d3f84..f6cd60f 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -134,7 +134,6 @@ extern unsigned long nr_running(void);
extern unsigned long nr_uninterruptible(void);
extern unsigned long nr_active(void);
extern unsigned long nr_iowait(void);
-extern unsigned long weighted_cpuload(const int cpu);
struct seq_file;
struct cfs_rq;
@@ -784,6 +783,8 @@ struct sched_domain {
unsigned int balance_interval; /* initialise to 1. units in ms. */
unsigned int nr_balance_failed; /* initialise to 0 */
+ u64 last_update;
+
#ifdef CONFIG_SCHEDSTATS
/* load_balance() stats */
unsigned int lb_count[CPU_MAX_IDLE_TYPES];
@@ -823,23 +824,6 @@ extern int arch_reinit_sched_domains(void);
#endif /* CONFIG_SMP */
-/*
- * A runqueue laden with a single nice 0 task scores a weighted_cpuload of
- * SCHED_LOAD_SCALE. This function returns 1 if any cpu is laden with a
- * task of nice 0 or enough lower priority tasks to bring up the
- * weighted_cpuload
- */
-static inline int above_background_load(void)
-{
- unsigned long cpu;
-
- for_each_online_cpu(cpu) {
- if (weighted_cpuload(cpu) >= SCHED_LOAD_SCALE)
- return 1;
- }
- return 0;
-}
-
struct io_context; /* See blkdev.h */
#define NGROUPS_SMALL 32
#define NGROUPS_PER_BLOCK ((unsigned int)(PAGE_SIZE / sizeof(gid_t)))
@@ -921,8 +905,8 @@ struct sched_class {
void (*set_cpus_allowed)(struct task_struct *p,
const cpumask_t *newmask);
- void (*join_domain)(struct rq *rq);
- void (*leave_domain)(struct rq *rq);
+ void (*rq_online)(struct rq *rq);
+ void (*rq_offline)(struct rq *rq);
void (*switched_from) (struct rq *this_rq, struct task_struct *task,
int running);
@@ -1039,6 +1023,7 @@ struct task_struct {
#endif
int prio, static_prio, normal_prio;
+ unsigned int rt_priority;
const struct sched_class *sched_class;
struct sched_entity se;
struct sched_rt_entity rt;
@@ -1122,7 +1107,6 @@ struct task_struct {
int __user *set_child_tid; /* CLONE_CHILD_SETTID */
int __user *clear_child_tid; /* CLONE_CHILD_CLEARTID */
- unsigned int rt_priority;
cputime_t utime, stime, utimescaled, stimescaled;
cputime_t gtime;
cputime_t prev_utime, prev_stime;
@@ -1141,12 +1125,12 @@ struct task_struct {
gid_t gid,egid,sgid,fsgid;
struct group_info *group_info;
kernel_cap_t cap_effective, cap_inheritable, cap_permitted, cap_bset;
- unsigned securebits;
struct user_struct *user;
+ unsigned securebits;
#ifdef CONFIG_KEYS
+ unsigned char jit_keyring; /* default keyring to attach requested keys to */
struct key *request_key_auth; /* assumed request_key authority */
struct key *thread_keyring; /* keyring private to this thread */
- unsigned char jit_keyring; /* default keyring to attach requested keys to */
#endif
char comm[TASK_COMM_LEN]; /* executable name excluding path
- access with [gs]et_task_comm (which lock
@@ -1233,8 +1217,8 @@ struct task_struct {
# define MAX_LOCK_DEPTH 48UL
u64 curr_chain_key;
int lockdep_depth;
- struct held_lock held_locks[MAX_LOCK_DEPTH];
unsigned int lockdep_recursion;
+ struct held_lock held_locks[MAX_LOCK_DEPTH];
#endif
/* journalling filesystem info */
@@ -1262,10 +1246,6 @@ struct task_struct {
u64 acct_vm_mem1; /* accumulated virtual memory usage */
cputime_t acct_stimexpd;/* stime since last update */
#endif
-#ifdef CONFIG_NUMA
- struct mempolicy *mempolicy;
- short il_next;
-#endif
#ifdef CONFIG_CPUSETS
nodemask_t mems_allowed;
int cpuset_mems_generation;
@@ -1285,6 +1265,10 @@ struct task_struct {
struct list_head pi_state_list;
struct futex_pi_state *pi_state_cache;
#endif
+#ifdef CONFIG_NUMA
+ struct mempolicy *mempolicy;
+ short il_next;
+#endif
atomic_t fs_excl; /* holding fs exclusive resources */
struct rcu_head rcu;
@@ -1504,6 +1488,7 @@ static inline void put_task_struct(struct task_struct *t)
#define PF_SWAPWRITE 0x00800000 /* Allowed to write to swap */
#define PF_SPREAD_PAGE 0x01000000 /* Spread page cache over cpuset */
#define PF_SPREAD_SLAB 0x02000000 /* Spread some slab caches over cpuset */
+#define PF_THREAD_BOUND 0x04000000 /* Thread bound to specific cpu */
#define PF_MEMPOLICY 0x10000000 /* Non-default NUMA mempolicy */
#define PF_MUTEX_TESTER 0x20000000 /* Thread belongs to the rt mutex tester */
#define PF_FREEZER_SKIP 0x40000000 /* Freezer should not count it as freezeable */
@@ -1573,13 +1558,28 @@ static inline void sched_clock_idle_sleep_event(void)
static inline void sched_clock_idle_wakeup_event(u64 delta_ns)
{
}
-#else
+
+#ifdef CONFIG_NO_HZ
+static inline void sched_clock_tick_stop(int cpu)
+{
+}
+
+static inline void sched_clock_tick_start(int cpu)
+{
+}
+#endif
+
+#else /* CONFIG_HAVE_UNSTABLE_SCHED_CLOCK */
extern void sched_clock_init(void);
extern u64 sched_clock_cpu(int cpu);
extern void sched_clock_tick(void);
extern void sched_clock_idle_sleep_event(void);
extern void sched_clock_idle_wakeup_event(u64 delta_ns);
+#ifdef CONFIG_NO_HZ
+extern void sched_clock_tick_stop(int cpu);
+extern void sched_clock_tick_start(int cpu);
#endif
+#endif /* CONFIG_HAVE_UNSTABLE_SCHED_CLOCK */
/*
* For kernel-internal use: high-speed (but slightly incorrect) per-cpu
@@ -1622,6 +1622,7 @@ extern unsigned int sysctl_sched_child_runs_first;
extern unsigned int sysctl_sched_features;
extern unsigned int sysctl_sched_migration_cost;
extern unsigned int sysctl_sched_nr_migrate;
+extern unsigned int sysctl_sched_shares_ratelimit;
int sched_nr_latency_handler(struct ctl_table *table, int write,
struct file *file, void __user *buffer, size_t *length,
diff --git a/kernel/Makefile b/kernel/Makefile
index 1c9938a..6c55301 100644
--- a/kernel/Makefile
+++ b/kernel/Makefile
@@ -3,7 +3,7 @@
#
obj-y = sched.o fork.o exec_domain.o panic.o printk.o profile.o \
- exit.o itimer.o time.o softirq.o resource.o \
+ cpu.o exit.o itimer.o time.o softirq.o resource.o \
sysctl.o capability.o ptrace.o timer.o user.o \
signal.o sys.o kmod.o workqueue.o pid.o \
rcupdate.o extable.o params.o posix-timers.o \
@@ -27,7 +27,7 @@ obj-$(CONFIG_RT_MUTEXES) += rtmutex.o
obj-$(CONFIG_DEBUG_RT_MUTEXES) += rtmutex-debug.o
obj-$(CONFIG_RT_MUTEX_TESTER) += rtmutex-tester.o
obj-$(CONFIG_GENERIC_ISA_DMA) += dma.o
-obj-$(CONFIG_SMP) += cpu.o spinlock.o
+obj-$(CONFIG_SMP) += spinlock.o
obj-$(CONFIG_DEBUG_SPINLOCK) += spinlock.o
obj-$(CONFIG_PROVE_LOCKING) += spinlock.o
obj-$(CONFIG_UID16) += uid16.o
@@ -69,6 +69,7 @@ obj-$(CONFIG_TASK_DELAY_ACCT) += delayacct.o
obj-$(CONFIG_TASKSTATS) += taskstats.o tsacct.o
obj-$(CONFIG_MARKERS) += marker.o
obj-$(CONFIG_LATENCYTOP) += latencytop.o
+obj-$(CONFIG_SMP) += sched_cpupri.o
ifneq ($(CONFIG_SCHED_NO_NO_OMIT_FRAME_POINTER),y)
# According to Alan Modra <alan@...uxcare.com.au>, the -fno-omit-frame-pointer is
diff --git a/kernel/cpu.c b/kernel/cpu.c
index c77bc3a..b11f06d 100644
--- a/kernel/cpu.c
+++ b/kernel/cpu.c
@@ -15,6 +15,28 @@
#include <linux/stop_machine.h>
#include <linux/mutex.h>
+/*
+ * Represents all cpu's present in the system
+ * In systems capable of hotplug, this map could dynamically grow
+ * as new cpu's are detected in the system via any platform specific
+ * method, such as ACPI for e.g.
+ */
+cpumask_t cpu_present_map __read_mostly;
+EXPORT_SYMBOL(cpu_present_map);
+
+#ifndef CONFIG_SMP
+
+/*
+ * Represents all cpu's that are currently online.
+ */
+cpumask_t cpu_online_map __read_mostly = CPU_MASK_ALL;
+EXPORT_SYMBOL(cpu_online_map);
+
+cpumask_t cpu_possible_map __read_mostly = CPU_MASK_ALL;
+EXPORT_SYMBOL(cpu_possible_map);
+
+#else /* CONFIG_SMP */
+
/* Serializes the updates to cpu_online_map, cpu_present_map */
static DEFINE_MUTEX(cpu_add_remove_lock);
@@ -403,3 +425,5 @@ out:
cpu_maps_update_done();
}
#endif /* CONFIG_PM_SLEEP_SMP */
+
+#endif /* CONFIG_SMP */
diff --git a/kernel/cpuset.c b/kernel/cpuset.c
index 798b3ab..459d601 100644
--- a/kernel/cpuset.c
+++ b/kernel/cpuset.c
@@ -1194,6 +1194,15 @@ static int cpuset_can_attach(struct cgroup_subsys *ss,
if (cpus_empty(cs->cpus_allowed) || nodes_empty(cs->mems_allowed))
return -ENOSPC;
+ if (tsk->flags & PF_THREAD_BOUND) {
+ cpumask_t mask;
+
+ mutex_lock(&callback_mutex);
+ mask = cs->cpus_allowed;
+ mutex_unlock(&callback_mutex);
+ if (!cpus_equal(tsk->cpus_allowed, mask))
+ return -EINVAL;
+ }
return security_task_setscheduler(tsk, 0, NULL);
}
@@ -1207,11 +1216,14 @@ static void cpuset_attach(struct cgroup_subsys *ss,
struct mm_struct *mm;
struct cpuset *cs = cgroup_cs(cont);
struct cpuset *oldcs = cgroup_cs(oldcont);
+ int err;
mutex_lock(&callback_mutex);
guarantee_online_cpus(cs, &cpus);
- set_cpus_allowed_ptr(tsk, &cpus);
+ err = set_cpus_allowed_ptr(tsk, &cpus);
mutex_unlock(&callback_mutex);
+ if (err)
+ return;
from = oldcs->mems_allowed;
to = cs->mems_allowed;
diff --git a/kernel/kthread.c b/kernel/kthread.c
index bd1b9ea..97747cd 100644
--- a/kernel/kthread.c
+++ b/kernel/kthread.c
@@ -180,6 +180,7 @@ void kthread_bind(struct task_struct *k, unsigned int cpu)
set_task_cpu(k, cpu);
k->cpus_allowed = cpumask_of_cpu(cpu);
k->rt.nr_cpus_allowed = 1;
+ k->flags |= PF_THREAD_BOUND;
}
EXPORT_SYMBOL(kthread_bind);
diff --git a/kernel/sched.c b/kernel/sched.c
index 4e2f603..d16c8d9 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -74,6 +74,8 @@
#include <asm/tlb.h>
#include <asm/irq_regs.h>
+#include "sched_cpupri.h"
+
/*
* Convert user-nice values [ -20 ... 0 ... 19 ]
* to static priority [ MAX_RT_PRIO..MAX_PRIO-1 ],
@@ -289,15 +291,15 @@ struct task_group root_task_group;
static DEFINE_PER_CPU(struct sched_entity, init_sched_entity);
/* Default task group's cfs_rq on each cpu */
static DEFINE_PER_CPU(struct cfs_rq, init_cfs_rq) ____cacheline_aligned_in_smp;
-#endif
+#endif /* CONFIG_FAIR_GROUP_SCHED */
#ifdef CONFIG_RT_GROUP_SCHED
static DEFINE_PER_CPU(struct sched_rt_entity, init_sched_rt_entity);
static DEFINE_PER_CPU(struct rt_rq, init_rt_rq) ____cacheline_aligned_in_smp;
-#endif
-#else
+#endif /* CONFIG_RT_GROUP_SCHED */
+#else /* !CONFIG_FAIR_GROUP_SCHED */
#define root_task_group init_task_group
-#endif
+#endif /* CONFIG_FAIR_GROUP_SCHED */
/* task_group_lock serializes add/remove of task groups and also changes to
* a task group's cpu shares.
@@ -307,9 +309,9 @@ static DEFINE_SPINLOCK(task_group_lock);
#ifdef CONFIG_FAIR_GROUP_SCHED
#ifdef CONFIG_USER_SCHED
# define INIT_TASK_GROUP_LOAD (2*NICE_0_LOAD)
-#else
+#else /* !CONFIG_USER_SCHED */
# define INIT_TASK_GROUP_LOAD NICE_0_LOAD
-#endif
+#endif /* CONFIG_USER_SCHED */
/*
* A weight of 0 or 1 can cause arithmetics problems.
@@ -363,6 +365,10 @@ static inline void set_task_rq(struct task_struct *p, unsigned int cpu)
#else
static inline void set_task_rq(struct task_struct *p, unsigned int cpu) { }
+static inline struct task_group *task_group(struct task_struct *p)
+{
+ return NULL;
+}
#endif /* CONFIG_GROUP_SCHED */
@@ -373,6 +379,7 @@ struct cfs_rq {
u64 exec_clock;
u64 min_vruntime;
+ u64 pair_start;
struct rb_root tasks_timeline;
struct rb_node *rb_leftmost;
@@ -401,6 +408,31 @@ struct cfs_rq {
*/
struct list_head leaf_cfs_rq_list;
struct task_group *tg; /* group that "owns" this runqueue */
+
+#ifdef CONFIG_SMP
+ /*
+ * the part of load.weight contributed by tasks
+ */
+ unsigned long task_weight;
+
+ /*
+ * h_load = weight * f(tg)
+ *
+ * Where f(tg) is the recursive weight fraction assigned to
+ * this group.
+ */
+ unsigned long h_load;
+
+ /*
+ * this cpu's part of tg->shares
+ */
+ unsigned long shares;
+
+ /*
+ * load.weight at the time we set shares
+ */
+ unsigned long rq_weight;
+#endif
#endif
};
@@ -452,6 +484,9 @@ struct root_domain {
*/
cpumask_t rto_mask;
atomic_t rto_count;
+#ifdef CONFIG_SMP
+ struct cpupri cpupri;
+#endif
};
/*
@@ -526,6 +561,9 @@ struct rq {
int push_cpu;
/* cpu of this runqueue: */
int cpu;
+ int online;
+
+ unsigned long avg_load_per_task;
struct task_struct *migration_thread;
struct list_head migration_queue;
@@ -749,6 +787,12 @@ late_initcall(sched_init_debug);
const_debug unsigned int sysctl_sched_nr_migrate = 32;
/*
+ * ratelimit for updating the group shares.
+ * default: 0.5ms
+ */
+const_debug unsigned int sysctl_sched_shares_ratelimit = 500000;
+
+/*
* period over which we measure -rt task cpu usage in us.
* default: 1s
*/
@@ -775,82 +819,6 @@ static inline u64 global_rt_runtime(void)
return (u64)sysctl_sched_rt_runtime * NSEC_PER_USEC;
}
-unsigned long long time_sync_thresh = 100000;
-
-static DEFINE_PER_CPU(unsigned long long, time_offset);
-static DEFINE_PER_CPU(unsigned long long, prev_cpu_time);
-
-/*
- * Global lock which we take every now and then to synchronize
- * the CPUs time. This method is not warp-safe, but it's good
- * enough to synchronize slowly diverging time sources and thus
- * it's good enough for tracing:
- */
-static DEFINE_SPINLOCK(time_sync_lock);
-static unsigned long long prev_global_time;
-
-static unsigned long long __sync_cpu_clock(unsigned long long time, int cpu)
-{
- /*
- * We want this inlined, to not get tracer function calls
- * in this critical section:
- */
- spin_acquire(&time_sync_lock.dep_map, 0, 0, _THIS_IP_);
- __raw_spin_lock(&time_sync_lock.raw_lock);
-
- if (time < prev_global_time) {
- per_cpu(time_offset, cpu) += prev_global_time - time;
- time = prev_global_time;
- } else {
- prev_global_time = time;
- }
-
- __raw_spin_unlock(&time_sync_lock.raw_lock);
- spin_release(&time_sync_lock.dep_map, 1, _THIS_IP_);
-
- return time;
-}
-
-static unsigned long long __cpu_clock(int cpu)
-{
- unsigned long long now;
-
- /*
- * Only call sched_clock() if the scheduler has already been
- * initialized (some code might call cpu_clock() very early):
- */
- if (unlikely(!scheduler_running))
- return 0;
-
- now = sched_clock_cpu(cpu);
-
- return now;
-}
-
-/*
- * For kernel-internal use: high-speed (but slightly incorrect) per-cpu
- * clock constructed from sched_clock():
- */
-unsigned long long cpu_clock(int cpu)
-{
- unsigned long long prev_cpu_time, time, delta_time;
- unsigned long flags;
-
- local_irq_save(flags);
- prev_cpu_time = per_cpu(prev_cpu_time, cpu);
- time = __cpu_clock(cpu) + per_cpu(time_offset, cpu);
- delta_time = time-prev_cpu_time;
-
- if (unlikely(delta_time > time_sync_thresh)) {
- time = __sync_cpu_clock(time, cpu);
- per_cpu(prev_cpu_time, cpu) = time;
- }
- local_irq_restore(flags);
-
- return time;
-}
-EXPORT_SYMBOL_GPL(cpu_clock);
-
#ifndef prepare_arch_switch
# define prepare_arch_switch(next) do { } while (0)
#endif
@@ -1313,15 +1281,15 @@ void wake_up_idle_cpu(int cpu)
if (!tsk_is_polling(rq->idle))
smp_send_reschedule(cpu);
}
-#endif
+#endif /* CONFIG_NO_HZ */
-#else
+#else /* !CONFIG_SMP */
static void __resched_task(struct task_struct *p, int tif_bit)
{
assert_spin_locked(&task_rq(p)->lock);
set_tsk_thread_flag(p, tif_bit);
}
-#endif
+#endif /* CONFIG_SMP */
#if BITS_PER_LONG == 32
# define WMULT_CONST (~0UL)
@@ -1336,6 +1304,9 @@ static void __resched_task(struct task_struct *p, int tif_bit)
*/
#define SRR(x, y) (((x) + (1UL << ((y) - 1))) >> (y))
+/*
+ * delta *= weight / lw
+ */
static unsigned long
calc_delta_mine(unsigned long delta_exec, unsigned long weight,
struct load_weight *lw)
@@ -1363,12 +1334,6 @@ calc_delta_mine(unsigned long delta_exec, unsigned long weight,
return (unsigned long)min(tmp, (u64)(unsigned long)LONG_MAX);
}
-static inline unsigned long
-calc_delta_fair(unsigned long delta_exec, struct load_weight *lw)
-{
- return calc_delta_mine(delta_exec, NICE_0_LOAD, lw);
-}
-
static inline void update_load_add(struct load_weight *lw, unsigned long inc)
{
lw->weight += inc;
@@ -1479,17 +1444,211 @@ static inline void dec_cpu_load(struct rq *rq, unsigned long load)
#ifdef CONFIG_SMP
static unsigned long source_load(int cpu, int type);
static unsigned long target_load(int cpu, int type);
-static unsigned long cpu_avg_load_per_task(int cpu);
static int task_hot(struct task_struct *p, u64 now, struct sched_domain *sd);
-#else /* CONFIG_SMP */
+
+static unsigned long cpu_avg_load_per_task(int cpu)
+{
+ struct rq *rq = cpu_rq(cpu);
+
+ if (rq->nr_running)
+ rq->avg_load_per_task = rq->load.weight / rq->nr_running;
+
+ return rq->avg_load_per_task;
+}
#ifdef CONFIG_FAIR_GROUP_SCHED
-static void cfs_rq_set_shares(struct cfs_rq *cfs_rq, unsigned long shares)
+
+typedef void (*tg_visitor)(struct task_group *, int, struct sched_domain *);
+
+/*
+ * Iterate the full tree, calling @down when first entering a node and @up when
+ * leaving it for the final time.
+ */
+static void
+walk_tg_tree(tg_visitor down, tg_visitor up, int cpu, struct sched_domain *sd)
+{
+ struct task_group *parent, *child;
+
+ rcu_read_lock();
+ parent = &root_task_group;
+down:
+ (*down)(parent, cpu, sd);
+ list_for_each_entry_rcu(child, &parent->children, siblings) {
+ parent = child;
+ goto down;
+
+up:
+ continue;
+ }
+ (*up)(parent, cpu, sd);
+
+ child = parent;
+ parent = parent->parent;
+ if (parent)
+ goto up;
+ rcu_read_unlock();
+}
+
+static void __set_se_shares(struct sched_entity *se, unsigned long shares);
+
+/*
+ * Calculate and set the cpu's group shares.
+ */
+static void
+__update_group_shares_cpu(struct task_group *tg, int cpu,
+ unsigned long sd_shares, unsigned long sd_rq_weight)
{
+ int boost = 0;
+ unsigned long shares;
+ unsigned long rq_weight;
+
+ if (!tg->se[cpu])
+ return;
+
+ rq_weight = tg->cfs_rq[cpu]->load.weight;
+
+ /*
+ * If there are currently no tasks on the cpu pretend there is one of
+ * average load so that when a new task gets to run here it will not
+ * get delayed by group starvation.
+ */
+ if (!rq_weight) {
+ boost = 1;
+ rq_weight = NICE_0_LOAD;
+ }
+
+ if (unlikely(rq_weight > sd_rq_weight))
+ rq_weight = sd_rq_weight;
+
+ /*
+ * \Sum shares * rq_weight
+ * shares = -----------------------
+ * \Sum rq_weight
+ *
+ */
+ shares = (sd_shares * rq_weight) / (sd_rq_weight + 1);
+
+ /*
+ * record the actual number of shares, not the boosted amount.
+ */
+ tg->cfs_rq[cpu]->shares = boost ? 0 : shares;
+ tg->cfs_rq[cpu]->rq_weight = rq_weight;
+
+ if (shares < MIN_SHARES)
+ shares = MIN_SHARES;
+ else if (shares > MAX_SHARES)
+ shares = MAX_SHARES;
+
+ __set_se_shares(tg->se[cpu], shares);
}
+
+/*
+ * Re-compute the task group their per cpu shares over the given domain.
+ * This needs to be done in a bottom-up fashion because the rq weight of a
+ * parent group depends on the shares of its child groups.
+ */
+static void
+tg_shares_up(struct task_group *tg, int cpu, struct sched_domain *sd)
+{
+ unsigned long rq_weight = 0;
+ unsigned long shares = 0;
+ int i;
+
+ for_each_cpu_mask(i, sd->span) {
+ rq_weight += tg->cfs_rq[i]->load.weight;
+ shares += tg->cfs_rq[i]->shares;
+ }
+
+ if ((!shares && rq_weight) || shares > tg->shares)
+ shares = tg->shares;
+
+ if (!sd->parent || !(sd->parent->flags & SD_LOAD_BALANCE))
+ shares = tg->shares;
+
+ if (!rq_weight)
+ rq_weight = cpus_weight(sd->span) * NICE_0_LOAD;
+
+ for_each_cpu_mask(i, sd->span) {
+ struct rq *rq = cpu_rq(i);
+ unsigned long flags;
+
+ spin_lock_irqsave(&rq->lock, flags);
+ __update_group_shares_cpu(tg, i, shares, rq_weight);
+ spin_unlock_irqrestore(&rq->lock, flags);
+ }
+}
+
+/*
+ * Compute the cpu's hierarchical load factor for each task group.
+ * This needs to be done in a top-down fashion because the load of a child
+ * group is a fraction of its parents load.
+ */
+static void
+tg_load_down(struct task_group *tg, int cpu, struct sched_domain *sd)
+{
+ unsigned long load;
+
+ if (!tg->parent) {
+ load = cpu_rq(cpu)->load.weight;
+ } else {
+ load = tg->parent->cfs_rq[cpu]->h_load;
+ load *= tg->cfs_rq[cpu]->shares;
+ load /= tg->parent->cfs_rq[cpu]->load.weight + 1;
+ }
+
+ tg->cfs_rq[cpu]->h_load = load;
+}
+
+static void
+tg_nop(struct task_group *tg, int cpu, struct sched_domain *sd)
+{
+}
+
+static void update_shares(struct sched_domain *sd)
+{
+ u64 now = cpu_clock(raw_smp_processor_id());
+ s64 elapsed = now - sd->last_update;
+
+ if (elapsed >= (s64)(u64)sysctl_sched_shares_ratelimit) {
+ sd->last_update = now;
+ walk_tg_tree(tg_nop, tg_shares_up, 0, sd);
+ }
+}
+
+static void update_shares_locked(struct rq *rq, struct sched_domain *sd)
+{
+ spin_unlock(&rq->lock);
+ update_shares(sd);
+ spin_lock(&rq->lock);
+}
+
+static void update_h_load(int cpu)
+{
+ walk_tg_tree(tg_load_down, tg_nop, cpu, NULL);
+}
+
+#else
+
+static inline void update_shares(struct sched_domain *sd)
+{
+}
+
+static inline void update_shares_locked(struct rq *rq, struct sched_domain *sd)
+{
+}
+
#endif
-#endif /* CONFIG_SMP */
+#endif
+
+#ifdef CONFIG_FAIR_GROUP_SCHED
+static void cfs_rq_set_shares(struct cfs_rq *cfs_rq, unsigned long shares)
+{
+#ifdef CONFIG_SMP
+ cfs_rq->shares = shares;
+#endif
+}
+#endif
#include "sched_stats.h"
#include "sched_idletask.c"
@@ -1500,27 +1659,17 @@ static void cfs_rq_set_shares(struct cfs_rq *cfs_rq, unsigned long shares)
#endif
#define sched_class_highest (&rt_sched_class)
+#define for_each_class(class) \
+ for (class = sched_class_highest; class; class = class->next)
-static inline void inc_load(struct rq *rq, const struct task_struct *p)
-{
- update_load_add(&rq->load, p->se.load.weight);
-}
-
-static inline void dec_load(struct rq *rq, const struct task_struct *p)
-{
- update_load_sub(&rq->load, p->se.load.weight);
-}
-
-static void inc_nr_running(struct task_struct *p, struct rq *rq)
+static void inc_nr_running(struct rq *rq)
{
rq->nr_running++;
- inc_load(rq, p);
}
-static void dec_nr_running(struct task_struct *p, struct rq *rq)
+static void dec_nr_running(struct rq *rq)
{
rq->nr_running--;
- dec_load(rq, p);
}
static void set_load_weight(struct task_struct *p)
@@ -1544,6 +1693,12 @@ static void set_load_weight(struct task_struct *p)
p->se.load.inv_weight = prio_to_wmult[p->static_prio - MAX_RT_PRIO];
}
+static void update_avg(u64 *avg, u64 sample)
+{
+ s64 diff = sample - *avg;
+ *avg += diff >> 3;
+}
+
static void enqueue_task(struct rq *rq, struct task_struct *p, int wakeup)
{
sched_info_queued(p);
@@ -1553,6 +1708,13 @@ static void enqueue_task(struct rq *rq, struct task_struct *p, int wakeup)
static void dequeue_task(struct rq *rq, struct task_struct *p, int sleep)
{
+ if (sleep && p->se.last_wakeup) {
+ update_avg(&p->se.avg_overlap,
+ p->se.sum_exec_runtime - p->se.last_wakeup);
+ p->se.last_wakeup = 0;
+ }
+
+ sched_info_dequeued(p);
p->sched_class->dequeue_task(rq, p, sleep);
p->se.on_rq = 0;
}
@@ -1612,7 +1774,7 @@ static void activate_task(struct rq *rq, struct task_struct *p, int wakeup)
rq->nr_uninterruptible--;
enqueue_task(rq, p, wakeup);
- inc_nr_running(p, rq);
+ inc_nr_running(rq);
}
/*
@@ -1624,7 +1786,7 @@ static void deactivate_task(struct rq *rq, struct task_struct *p, int sleep)
rq->nr_uninterruptible++;
dequeue_task(rq, p, sleep);
- dec_nr_running(p, rq);
+ dec_nr_running(rq);
}
/**
@@ -1636,12 +1798,6 @@ inline int task_curr(const struct task_struct *p)
return cpu_curr(task_cpu(p)) == p;
}
-/* Used instead of source_load when we know the type == 0 */
-unsigned long weighted_cpuload(const int cpu)
-{
- return cpu_rq(cpu)->load.weight;
-}
-
static inline void __set_task_cpu(struct task_struct *p, unsigned int cpu)
{
set_task_rq(p, cpu);
@@ -1670,6 +1826,12 @@ static inline void check_class_changed(struct rq *rq, struct task_struct *p,
#ifdef CONFIG_SMP
+/* Used instead of source_load when we know the type == 0 */
+static unsigned long weighted_cpuload(const int cpu)
+{
+ return cpu_rq(cpu)->load.weight;
+}
+
/*
* Is this task likely cache-hot:
*/
@@ -1880,7 +2042,7 @@ static unsigned long source_load(int cpu, int type)
struct rq *rq = cpu_rq(cpu);
unsigned long total = weighted_cpuload(cpu);
- if (type == 0)
+ if (type == 0 || !sched_feat(LB_BIAS))
return total;
return min(rq->cpu_load[type-1], total);
@@ -1895,25 +2057,13 @@ static unsigned long target_load(int cpu, int type)
struct rq *rq = cpu_rq(cpu);
unsigned long total = weighted_cpuload(cpu);
- if (type == 0)
+ if (type == 0 || !sched_feat(LB_BIAS))
return total;
return max(rq->cpu_load[type-1], total);
}
/*
- * Return the average load per task on the cpu's run queue
- */
-static unsigned long cpu_avg_load_per_task(int cpu)
-{
- struct rq *rq = cpu_rq(cpu);
- unsigned long total = weighted_cpuload(cpu);
- unsigned long n = rq->nr_running;
-
- return n ? total / n : SCHED_LOAD_SCALE;
-}
-
-/*
* find_idlest_group finds and returns the least busy CPU group within the
* domain.
*/
@@ -2019,6 +2169,9 @@ static int sched_balance_self(int cpu, int flag)
sd = tmp;
}
+ if (sd)
+ update_shares(sd);
+
while (sd) {
cpumask_t span, tmpmask;
struct sched_group *group;
@@ -2085,6 +2238,22 @@ static int try_to_wake_up(struct task_struct *p, unsigned int state, int sync)
if (!sched_feat(SYNC_WAKEUPS))
sync = 0;
+#ifdef CONFIG_SMP
+ if (sched_feat(LB_WAKEUP_UPDATE)) {
+ struct sched_domain *sd;
+
+ this_cpu = raw_smp_processor_id();
+ cpu = task_cpu(p);
+
+ for_each_domain(this_cpu, sd) {
+ if (cpu_isset(cpu, sd->span)) {
+ update_shares(sd);
+ break;
+ }
+ }
+ }
+#endif
+
smp_wmb();
rq = task_rq_lock(p, &flags);
old_state = p->state;
@@ -2131,7 +2300,7 @@ static int try_to_wake_up(struct task_struct *p, unsigned int state, int sync)
}
}
}
-#endif
+#endif /* CONFIG_SCHEDSTATS */
out_activate:
#endif /* CONFIG_SMP */
@@ -2157,6 +2326,8 @@ out_running:
p->sched_class->task_wake_up(rq, p);
#endif
out:
+ current->se.last_wakeup = current->se.sum_exec_runtime;
+
task_rq_unlock(rq, &flags);
return success;
@@ -2277,7 +2448,7 @@ void wake_up_new_task(struct task_struct *p, unsigned long clone_flags)
* management (if any):
*/
p->sched_class->task_new(rq, p);
- inc_nr_running(p, rq);
+ inc_nr_running(rq);
}
check_preempt_curr(rq, p);
#ifdef CONFIG_SMP
@@ -2331,7 +2502,7 @@ fire_sched_out_preempt_notifiers(struct task_struct *curr,
notifier->ops->sched_out(notifier, next);
}
-#else
+#else /* !CONFIG_PREEMPT_NOTIFIERS */
static void fire_sched_in_preempt_notifiers(struct task_struct *curr)
{
@@ -2343,7 +2514,7 @@ fire_sched_out_preempt_notifiers(struct task_struct *curr,
{
}
-#endif
+#endif /* CONFIG_PREEMPT_NOTIFIERS */
/**
* prepare_task_switch - prepare to switch tasks
@@ -2785,7 +2956,7 @@ balance_tasks(struct rq *this_rq, int this_cpu, struct rq *busiest,
enum cpu_idle_type idle, int *all_pinned,
int *this_best_prio, struct rq_iterator *iterator)
{
- int loops = 0, pulled = 0, pinned = 0, skip_for_load;
+ int loops = 0, pulled = 0, pinned = 0;
struct task_struct *p;
long rem_load_move = max_load_move;
@@ -2801,14 +2972,8 @@ balance_tasks(struct rq *this_rq, int this_cpu, struct rq *busiest,
next:
if (!p || loops++ > sysctl_sched_nr_migrate)
goto out;
- /*
- * To help distribute high priority tasks across CPUs we don't
- * skip a task if it will be the highest priority task (i.e. smallest
- * prio value) on its new queue regardless of its load weight
- */
- skip_for_load = (p->se.load.weight >> 1) > rem_load_move +
- SCHED_LOAD_SCALE_FUZZ;
- if ((skip_for_load && p->prio >= *this_best_prio) ||
+
+ if ((p->se.load.weight >> 1) > rem_load_move ||
!can_migrate_task(p, busiest, this_cpu, sd, idle, &pinned)) {
p = iterator->next(iterator->arg);
goto next;
@@ -2863,6 +3028,10 @@ static int move_tasks(struct rq *this_rq, int this_cpu, struct rq *busiest,
max_load_move - total_load_moved,
sd, idle, all_pinned, &this_best_prio);
class = class->next;
+
+ if (idle == CPU_NEWLY_IDLE && this_rq->nr_running)
+ break;
+
} while (class && max_load_move > total_load_moved);
return total_load_moved > 0;
@@ -2939,6 +3108,7 @@ find_busiest_group(struct sched_domain *sd, int this_cpu,
max_load = this_load = total_load = total_pwr = 0;
busiest_load_per_task = busiest_nr_running = 0;
this_load_per_task = this_nr_running = 0;
+
if (idle == CPU_NOT_IDLE)
load_idx = sd->busy_idx;
else if (idle == CPU_NEWLY_IDLE)
@@ -2953,6 +3123,8 @@ find_busiest_group(struct sched_domain *sd, int this_cpu,
int __group_imb = 0;
unsigned int balance_cpu = -1, first_idle_cpu = 0;
unsigned long sum_nr_running, sum_weighted_load;
+ unsigned long sum_avg_load_per_task;
+ unsigned long avg_load_per_task;
local_group = cpu_isset(this_cpu, group->cpumask);
@@ -2961,6 +3133,8 @@ find_busiest_group(struct sched_domain *sd, int this_cpu,
/* Tally up the load of all CPUs in the group */
sum_weighted_load = sum_nr_running = avg_load = 0;
+ sum_avg_load_per_task = avg_load_per_task = 0;
+
max_cpu_load = 0;
min_cpu_load = ~0UL;
@@ -2994,6 +3168,8 @@ find_busiest_group(struct sched_domain *sd, int this_cpu,
avg_load += load;
sum_nr_running += rq->nr_running;
sum_weighted_load += weighted_cpuload(i);
+
+ sum_avg_load_per_task += cpu_avg_load_per_task(i);
}
/*
@@ -3015,7 +3191,20 @@ find_busiest_group(struct sched_domain *sd, int this_cpu,
avg_load = sg_div_cpu_power(group,
avg_load * SCHED_LOAD_SCALE);
- if ((max_cpu_load - min_cpu_load) > SCHED_LOAD_SCALE)
+
+ /*
+ * Consider the group unbalanced when the imbalance is larger
+ * than the average weight of two tasks.
+ *
+ * APZ: with cgroup the avg task weight can vary wildly and
+ * might not be a suitable number - should we keep a
+ * normalized nr_running number somewhere that negates
+ * the hierarchy?
+ */
+ avg_load_per_task = sg_div_cpu_power(group,
+ sum_avg_load_per_task * SCHED_LOAD_SCALE);
+
+ if ((max_cpu_load - min_cpu_load) > 2*avg_load_per_task)
__group_imb = 1;
group_capacity = group->__cpu_power / SCHED_LOAD_SCALE;
@@ -3156,9 +3345,9 @@ small_imbalance:
if (busiest_load_per_task > this_load_per_task)
imbn = 1;
} else
- this_load_per_task = SCHED_LOAD_SCALE;
+ this_load_per_task = cpu_avg_load_per_task(this_cpu);
- if (max_load - this_load + SCHED_LOAD_SCALE_FUZZ >=
+ if (max_load - this_load + 2*busiest_load_per_task >=
busiest_load_per_task * imbn) {
*imbalance = busiest_load_per_task;
return busiest;
@@ -3284,6 +3473,7 @@ static int load_balance(int this_cpu, struct rq *this_rq,
schedstat_inc(sd, lb_count[idle]);
redo:
+ update_shares(sd);
group = find_busiest_group(sd, this_cpu, &imbalance, idle, &sd_idle,
cpus, balance);
@@ -3386,8 +3576,9 @@ redo:
if (!ld_moved && !sd_idle && sd->flags & SD_SHARE_CPUPOWER &&
!test_sd_parent(sd, SD_POWERSAVINGS_BALANCE))
- return -1;
- return ld_moved;
+ ld_moved = -1;
+
+ goto out;
out_balanced:
schedstat_inc(sd, lb_balanced[idle]);
@@ -3402,8 +3593,13 @@ out_one_pinned:
if (!sd_idle && sd->flags & SD_SHARE_CPUPOWER &&
!test_sd_parent(sd, SD_POWERSAVINGS_BALANCE))
- return -1;
- return 0;
+ ld_moved = -1;
+ else
+ ld_moved = 0;
+out:
+ if (ld_moved)
+ update_shares(sd);
+ return ld_moved;
}
/*
@@ -3438,6 +3634,7 @@ load_balance_newidle(int this_cpu, struct rq *this_rq, struct sched_domain *sd,
schedstat_inc(sd, lb_count[CPU_NEWLY_IDLE]);
redo:
+ update_shares_locked(this_rq, sd);
group = find_busiest_group(sd, this_cpu, &imbalance, CPU_NEWLY_IDLE,
&sd_idle, cpus, NULL);
if (!group) {
@@ -3481,6 +3678,7 @@ redo:
} else
sd->nr_balance_failed = 0;
+ update_shares_locked(this_rq, sd);
return ld_moved;
out_balanced:
@@ -3672,6 +3870,7 @@ static void rebalance_domains(int cpu, enum cpu_idle_type idle)
/* Earliest time when we have to do rebalance again */
unsigned long next_balance = jiffies + 60*HZ;
int update_next_balance = 0;
+ int need_serialize;
cpumask_t tmp;
for_each_domain(cpu, sd) {
@@ -3689,8 +3888,9 @@ static void rebalance_domains(int cpu, enum cpu_idle_type idle)
if (interval > HZ*NR_CPUS/10)
interval = HZ*NR_CPUS/10;
+ need_serialize = sd->flags & SD_SERIALIZE;
- if (sd->flags & SD_SERIALIZE) {
+ if (need_serialize) {
if (!spin_trylock(&balancing))
goto out;
}
@@ -3706,7 +3906,7 @@ static void rebalance_domains(int cpu, enum cpu_idle_type idle)
}
sd->last_balance = jiffies;
}
- if (sd->flags & SD_SERIALIZE)
+ if (need_serialize)
spin_unlock(&balancing);
out:
if (time_after(next_balance, sd->last_balance + interval)) {
@@ -4070,6 +4270,7 @@ static noinline void __schedule_bug(struct task_struct *prev)
prev->comm, prev->pid, preempt_count());
debug_show_held_locks(prev);
+ print_modules();
if (irqs_disabled())
print_irqtrace_events(prev);
@@ -4143,7 +4344,7 @@ asmlinkage void __sched schedule(void)
struct task_struct *prev, *next;
unsigned long *switch_count;
struct rq *rq;
- int cpu;
+ int cpu, hrtick = sched_feat(HRTICK);
need_resched:
preempt_disable();
@@ -4158,7 +4359,8 @@ need_resched_nonpreemptible:
schedule_debug(prev);
- hrtick_clear(rq);
+ if (hrtick)
+ hrtick_clear(rq);
/*
* Do the rq-clock update outside the rq lock:
@@ -4204,7 +4406,8 @@ need_resched_nonpreemptible:
} else
spin_unlock_irq(&rq->lock);
- hrtick_set(rq);
+ if (hrtick)
+ hrtick_set(rq);
if (unlikely(reacquire_kernel_lock(current) < 0))
goto need_resched_nonpreemptible;
@@ -4586,10 +4789,8 @@ void set_user_nice(struct task_struct *p, long nice)
goto out_unlock;
}
on_rq = p->se.on_rq;
- if (on_rq) {
+ if (on_rq)
dequeue_task(rq, p, 0);
- dec_load(rq, p);
- }
p->static_prio = NICE_TO_PRIO(nice);
set_load_weight(p);
@@ -4599,7 +4800,6 @@ void set_user_nice(struct task_struct *p, long nice)
if (on_rq) {
enqueue_task(rq, p, 0);
- inc_load(rq, p);
/*
* If the task increased its priority or is running and
* lowered its priority, then reschedule its CPU:
@@ -5070,24 +5270,6 @@ asmlinkage long sys_sched_setaffinity(pid_t pid, unsigned int len,
return sched_setaffinity(pid, &new_mask);
}
-/*
- * Represents all cpu's present in the system
- * In systems capable of hotplug, this map could dynamically grow
- * as new cpu's are detected in the system via any platform specific
- * method, such as ACPI for e.g.
- */
-
-cpumask_t cpu_present_map __read_mostly;
-EXPORT_SYMBOL(cpu_present_map);
-
-#ifndef CONFIG_SMP
-cpumask_t cpu_online_map __read_mostly = CPU_MASK_ALL;
-EXPORT_SYMBOL(cpu_online_map);
-
-cpumask_t cpu_possible_map __read_mostly = CPU_MASK_ALL;
-EXPORT_SYMBOL(cpu_possible_map);
-#endif
-
long sched_getaffinity(pid_t pid, cpumask_t *mask)
{
struct task_struct *p;
@@ -5571,6 +5753,12 @@ int set_cpus_allowed_ptr(struct task_struct *p, const cpumask_t *new_mask)
goto out;
}
+ if (unlikely((p->flags & PF_THREAD_BOUND) && p != current &&
+ !cpus_equal(p->cpus_allowed, *new_mask))) {
+ ret = -EINVAL;
+ goto out;
+ }
+
if (p->sched_class->set_cpus_allowed)
p->sched_class->set_cpus_allowed(p, new_mask);
else {
@@ -6060,6 +6248,36 @@ static void unregister_sched_domain_sysctl(void)
}
#endif
+static void set_rq_online(struct rq *rq)
+{
+ if (!rq->online) {
+ const struct sched_class *class;
+
+ cpu_set(rq->cpu, rq->rd->online);
+ rq->online = 1;
+
+ for_each_class(class) {
+ if (class->rq_online)
+ class->rq_online(rq);
+ }
+ }
+}
+
+static void set_rq_offline(struct rq *rq)
+{
+ if (rq->online) {
+ const struct sched_class *class;
+
+ for_each_class(class) {
+ if (class->rq_offline)
+ class->rq_offline(rq);
+ }
+
+ cpu_clear(rq->cpu, rq->rd->online);
+ rq->online = 0;
+ }
+}
+
/*
* migration_call - callback that gets triggered when a CPU is added.
* Here we can start up the necessary migration thread for the new CPU.
@@ -6097,7 +6315,8 @@ migration_call(struct notifier_block *nfb, unsigned long action, void *hcpu)
spin_lock_irqsave(&rq->lock, flags);
if (rq->rd) {
BUG_ON(!cpu_isset(cpu, rq->rd->span));
- cpu_set(cpu, rq->rd->online);
+
+ set_rq_online(rq);
}
spin_unlock_irqrestore(&rq->lock, flags);
break;
@@ -6158,7 +6377,7 @@ migration_call(struct notifier_block *nfb, unsigned long action, void *hcpu)
spin_lock_irqsave(&rq->lock, flags);
if (rq->rd) {
BUG_ON(!cpu_isset(cpu, rq->rd->span));
- cpu_clear(cpu, rq->rd->online);
+ set_rq_offline(rq);
}
spin_unlock_irqrestore(&rq->lock, flags);
break;
@@ -6192,6 +6411,28 @@ void __init migration_init(void)
#ifdef CONFIG_SCHED_DEBUG
+static inline const char *sd_level_to_string(enum sched_domain_level lvl)
+{
+ switch (lvl) {
+ case SD_LV_NONE:
+ return "NONE";
+ case SD_LV_SIBLING:
+ return "SIBLING";
+ case SD_LV_MC:
+ return "MC";
+ case SD_LV_CPU:
+ return "CPU";
+ case SD_LV_NODE:
+ return "NODE";
+ case SD_LV_ALLNODES:
+ return "ALLNODES";
+ case SD_LV_MAX:
+ return "MAX";
+
+ }
+ return "MAX";
+}
+
static int sched_domain_debug_one(struct sched_domain *sd, int cpu, int level,
cpumask_t *groupmask)
{
@@ -6211,7 +6452,8 @@ static int sched_domain_debug_one(struct sched_domain *sd, int cpu, int level,
return -1;
}
- printk(KERN_CONT "span %s\n", str);
+ printk(KERN_CONT "span %s level %s\n",
+ str, sd_level_to_string(sd->level));
if (!cpu_isset(cpu, sd->span)) {
printk(KERN_ERR "ERROR: domain->span does not contain "
@@ -6295,9 +6537,9 @@ static void sched_domain_debug(struct sched_domain *sd, int cpu)
}
kfree(groupmask);
}
-#else
+#else /* !CONFIG_SCHED_DEBUG */
# define sched_domain_debug(sd, cpu) do { } while (0)
-#endif
+#endif /* CONFIG_SCHED_DEBUG */
static int sd_degenerate(struct sched_domain *sd)
{
@@ -6357,20 +6599,16 @@ sd_parent_degenerate(struct sched_domain *sd, struct sched_domain *parent)
static void rq_attach_root(struct rq *rq, struct root_domain *rd)
{
unsigned long flags;
- const struct sched_class *class;
spin_lock_irqsave(&rq->lock, flags);
if (rq->rd) {
struct root_domain *old_rd = rq->rd;
- for (class = sched_class_highest; class; class = class->next) {
- if (class->leave_domain)
- class->leave_domain(rq);
- }
+ if (cpu_isset(rq->cpu, old_rd->online))
+ set_rq_offline(rq);
cpu_clear(rq->cpu, old_rd->span);
- cpu_clear(rq->cpu, old_rd->online);
if (atomic_dec_and_test(&old_rd->refcount))
kfree(old_rd);
@@ -6381,12 +6619,7 @@ static void rq_attach_root(struct rq *rq, struct root_domain *rd)
cpu_set(rq->cpu, rd->span);
if (cpu_isset(rq->cpu, cpu_online_map))
- cpu_set(rq->cpu, rd->online);
-
- for (class = sched_class_highest; class; class = class->next) {
- if (class->join_domain)
- class->join_domain(rq);
- }
+ set_rq_online(rq);
spin_unlock_irqrestore(&rq->lock, flags);
}
@@ -6397,6 +6630,8 @@ static void init_rootdomain(struct root_domain *rd)
cpus_clear(rd->span);
cpus_clear(rd->online);
+
+ cpupri_init(&rd->cpupri);
}
static void init_defrootdomain(void)
@@ -6591,7 +6826,7 @@ static void sched_domain_node_span(int node, cpumask_t *span)
cpus_or(*span, *span, *nodemask);
}
}
-#endif
+#endif /* CONFIG_NUMA */
int sched_smt_power_savings = 0, sched_mc_power_savings = 0;
@@ -6610,7 +6845,7 @@ cpu_to_cpu_group(int cpu, const cpumask_t *cpu_map, struct sched_group **sg,
*sg = &per_cpu(sched_group_cpus, cpu);
return cpu;
}
-#endif
+#endif /* CONFIG_SCHED_SMT */
/*
* multi-core sched-domains:
@@ -6618,7 +6853,7 @@ cpu_to_cpu_group(int cpu, const cpumask_t *cpu_map, struct sched_group **sg,
#ifdef CONFIG_SCHED_MC
static DEFINE_PER_CPU(struct sched_domain, core_domains);
static DEFINE_PER_CPU(struct sched_group, sched_group_core);
-#endif
+#endif /* CONFIG_SCHED_MC */
#if defined(CONFIG_SCHED_MC) && defined(CONFIG_SCHED_SMT)
static int
@@ -6720,7 +6955,7 @@ static void init_numa_sched_groups_power(struct sched_group *group_head)
sg = sg->next;
} while (sg != group_head);
}
-#endif
+#endif /* CONFIG_NUMA */
#ifdef CONFIG_NUMA
/* Free memory allocated for various sched_group structures */
@@ -6757,11 +6992,11 @@ next_sg:
sched_group_nodes_bycpu[cpu] = NULL;
}
}
-#else
+#else /* !CONFIG_NUMA */
static void free_sched_groups(const cpumask_t *cpu_map, cpumask_t *nodemask)
{
}
-#endif
+#endif /* CONFIG_NUMA */
/*
* Initialize sched groups cpu_power.
@@ -7470,7 +7705,7 @@ int sched_create_sysfs_power_savings_entries(struct sysdev_class *cls)
#endif
return err;
}
-#endif
+#endif /* CONFIG_SCHED_MC || CONFIG_SCHED_SMT */
/*
* Force a reinitialization of the sched domains hierarchy. The domains
@@ -7481,21 +7716,28 @@ int sched_create_sysfs_power_savings_entries(struct sysdev_class *cls)
static int update_sched_domains(struct notifier_block *nfb,
unsigned long action, void *hcpu)
{
+ int cpu = (int)(long)hcpu;
+
switch (action) {
- case CPU_UP_PREPARE:
- case CPU_UP_PREPARE_FROZEN:
case CPU_DOWN_PREPARE:
case CPU_DOWN_PREPARE_FROZEN:
+ disable_runtime(cpu_rq(cpu));
+ /* fall-through */
+ case CPU_UP_PREPARE:
+ case CPU_UP_PREPARE_FROZEN:
detach_destroy_domains(&cpu_online_map);
free_sched_domains();
return NOTIFY_OK;
- case CPU_UP_CANCELED:
- case CPU_UP_CANCELED_FROZEN:
+
case CPU_DOWN_FAILED:
case CPU_DOWN_FAILED_FROZEN:
case CPU_ONLINE:
case CPU_ONLINE_FROZEN:
+ enable_runtime(cpu_rq(cpu));
+ /* fall-through */
+ case CPU_UP_CANCELED:
+ case CPU_UP_CANCELED_FROZEN:
case CPU_DEAD:
case CPU_DEAD_FROZEN:
/*
@@ -7695,8 +7937,8 @@ void __init sched_init(void)
root_task_group.cfs_rq = (struct cfs_rq **)ptr;
ptr += nr_cpu_ids * sizeof(void **);
-#endif
-#endif
+#endif /* CONFIG_USER_SCHED */
+#endif /* CONFIG_FAIR_GROUP_SCHED */
#ifdef CONFIG_RT_GROUP_SCHED
init_task_group.rt_se = (struct sched_rt_entity **)ptr;
ptr += nr_cpu_ids * sizeof(void **);
@@ -7710,8 +7952,8 @@ void __init sched_init(void)
root_task_group.rt_rq = (struct rt_rq **)ptr;
ptr += nr_cpu_ids * sizeof(void **);
-#endif
-#endif
+#endif /* CONFIG_USER_SCHED */
+#endif /* CONFIG_RT_GROUP_SCHED */
}
#ifdef CONFIG_SMP
@@ -7727,8 +7969,8 @@ void __init sched_init(void)
#ifdef CONFIG_USER_SCHED
init_rt_bandwidth(&root_task_group.rt_bandwidth,
global_rt_period(), RUNTIME_INF);
-#endif
-#endif
+#endif /* CONFIG_USER_SCHED */
+#endif /* CONFIG_RT_GROUP_SCHED */
#ifdef CONFIG_GROUP_SCHED
list_add(&init_task_group.list, &task_groups);
@@ -7738,8 +7980,8 @@ void __init sched_init(void)
INIT_LIST_HEAD(&root_task_group.children);
init_task_group.parent = &root_task_group;
list_add(&init_task_group.siblings, &root_task_group.children);
-#endif
-#endif
+#endif /* CONFIG_USER_SCHED */
+#endif /* CONFIG_GROUP_SCHED */
for_each_possible_cpu(i) {
struct rq *rq;
@@ -7819,6 +8061,7 @@ void __init sched_init(void)
rq->next_balance = jiffies;
rq->push_cpu = 0;
rq->cpu = i;
+ rq->online = 0;
rq->migration_thread = NULL;
INIT_LIST_HEAD(&rq->migration_queue);
rq_attach_root(rq, &def_root_domain);
@@ -8058,7 +8301,7 @@ static inline void unregister_fair_sched_group(struct task_group *tg, int cpu)
{
list_del_rcu(&tg->cfs_rq[cpu]->leaf_cfs_rq_list);
}
-#else
+#else /* !CONFG_FAIR_GROUP_SCHED */
static inline void free_fair_sched_group(struct task_group *tg)
{
}
@@ -8076,7 +8319,7 @@ static inline void register_fair_sched_group(struct task_group *tg, int cpu)
static inline void unregister_fair_sched_group(struct task_group *tg, int cpu)
{
}
-#endif
+#endif /* CONFIG_FAIR_GROUP_SCHED */
#ifdef CONFIG_RT_GROUP_SCHED
static void free_rt_sched_group(struct task_group *tg)
@@ -8147,7 +8390,7 @@ static inline void unregister_rt_sched_group(struct task_group *tg, int cpu)
{
list_del_rcu(&tg->rt_rq[cpu]->leaf_rt_rq_list);
}
-#else
+#else /* !CONFIG_RT_GROUP_SCHED */
static inline void free_rt_sched_group(struct task_group *tg)
{
}
@@ -8165,7 +8408,7 @@ static inline void register_rt_sched_group(struct task_group *tg, int cpu)
static inline void unregister_rt_sched_group(struct task_group *tg, int cpu)
{
}
-#endif
+#endif /* CONFIG_RT_GROUP_SCHED */
#ifdef CONFIG_GROUP_SCHED
static void free_sched_group(struct task_group *tg)
@@ -8276,17 +8519,14 @@ void sched_move_task(struct task_struct *tsk)
task_rq_unlock(rq, &flags);
}
-#endif
+#endif /* CONFIG_GROUP_SCHED */
#ifdef CONFIG_FAIR_GROUP_SCHED
-static void set_se_shares(struct sched_entity *se, unsigned long shares)
+static void __set_se_shares(struct sched_entity *se, unsigned long shares)
{
struct cfs_rq *cfs_rq = se->cfs_rq;
- struct rq *rq = cfs_rq->rq;
int on_rq;
- spin_lock_irq(&rq->lock);
-
on_rq = se->on_rq;
if (on_rq)
dequeue_entity(cfs_rq, se, 0);
@@ -8296,8 +8536,17 @@ static void set_se_shares(struct sched_entity *se, unsigned long shares)
if (on_rq)
enqueue_entity(cfs_rq, se, 0);
+}
- spin_unlock_irq(&rq->lock);
+static void set_se_shares(struct sched_entity *se, unsigned long shares)
+{
+ struct cfs_rq *cfs_rq = se->cfs_rq;
+ struct rq *rq = cfs_rq->rq;
+ unsigned long flags;
+
+ spin_lock_irqsave(&rq->lock, flags);
+ __set_se_shares(se, shares);
+ spin_unlock_irqrestore(&rq->lock, flags);
}
static DEFINE_MUTEX(shares_mutex);
@@ -8336,8 +8585,13 @@ int sched_group_set_shares(struct task_group *tg, unsigned long shares)
* w/o tripping rebalance_share or load_balance_fair.
*/
tg->shares = shares;
- for_each_possible_cpu(i)
+ for_each_possible_cpu(i) {
+ /*
+ * force a rebalance
+ */
+ cfs_rq_set_shares(tg->cfs_rq[i], 0);
set_se_shares(tg->se[i], shares);
+ }
/*
* Enable load balance activity on this group, by inserting it back on
@@ -8376,7 +8630,7 @@ static unsigned long to_ratio(u64 period, u64 runtime)
#ifdef CONFIG_CGROUP_SCHED
static int __rt_schedulable(struct task_group *tg, u64 period, u64 runtime)
{
- struct task_group *tgi, *parent = tg ? tg->parent : NULL;
+ struct task_group *tgi, *parent = tg->parent;
unsigned long total = 0;
if (!parent) {
@@ -8400,7 +8654,7 @@ static int __rt_schedulable(struct task_group *tg, u64 period, u64 runtime)
}
rcu_read_unlock();
- return total + to_ratio(period, runtime) <
+ return total + to_ratio(period, runtime) <=
to_ratio(ktime_to_ns(parent->rt_bandwidth.rt_period),
parent->rt_bandwidth.rt_runtime);
}
@@ -8520,16 +8774,21 @@ long sched_group_rt_period(struct task_group *tg)
static int sched_rt_global_constraints(void)
{
+ struct task_group *tg = &root_task_group;
+ u64 rt_runtime, rt_period;
int ret = 0;
+ rt_period = ktime_to_ns(tg->rt_bandwidth.rt_period);
+ rt_runtime = tg->rt_bandwidth.rt_runtime;
+
mutex_lock(&rt_constraints_mutex);
- if (!__rt_schedulable(NULL, 1, 0))
+ if (!__rt_schedulable(tg, rt_period, rt_runtime))
ret = -EINVAL;
mutex_unlock(&rt_constraints_mutex);
return ret;
}
-#else
+#else /* !CONFIG_RT_GROUP_SCHED */
static int sched_rt_global_constraints(void)
{
unsigned long flags;
@@ -8547,7 +8806,7 @@ static int sched_rt_global_constraints(void)
return 0;
}
-#endif
+#endif /* CONFIG_RT_GROUP_SCHED */
int sched_rt_handler(struct ctl_table *table, int write,
struct file *filp, void __user *buffer, size_t *lenp,
@@ -8655,7 +8914,7 @@ static u64 cpu_shares_read_u64(struct cgroup *cgrp, struct cftype *cft)
return (u64) tg->shares;
}
-#endif
+#endif /* CONFIG_FAIR_GROUP_SCHED */
#ifdef CONFIG_RT_GROUP_SCHED
static int cpu_rt_runtime_write(struct cgroup *cgrp, struct cftype *cft,
@@ -8679,7 +8938,7 @@ static u64 cpu_rt_period_read_uint(struct cgroup *cgrp, struct cftype *cft)
{
return sched_group_rt_period(cgroup_tg(cgrp));
}
-#endif
+#endif /* CONFIG_RT_GROUP_SCHED */
static struct cftype cpu_files[] = {
#ifdef CONFIG_FAIR_GROUP_SCHED
diff --git a/kernel/sched_clock.c b/kernel/sched_clock.c
index ce05271..22ed55d 100644
--- a/kernel/sched_clock.c
+++ b/kernel/sched_clock.c
@@ -3,6 +3,9 @@
*
* Copyright (C) 2008 Red Hat, Inc., Peter Zijlstra <pzijlstr@...hat.com>
*
+ * Updates and enhancements:
+ * Copyright (C) 2008 Red Hat, Inc. Steven Rostedt <srostedt@...hat.com>
+ *
* Based on code by:
* Ingo Molnar <mingo@...hat.com>
* Guillaume Chazarain <guichaz@...il.com>
@@ -32,6 +35,11 @@
#ifdef CONFIG_HAVE_UNSTABLE_SCHED_CLOCK
+#define MULTI_SHIFT 15
+/* Max is double, Min is 1/2 */
+#define MAX_MULTI (2LL << MULTI_SHIFT)
+#define MIN_MULTI (1LL << (MULTI_SHIFT-1))
+
struct sched_clock_data {
/*
* Raw spinlock - this is a special case: this might be called
@@ -40,11 +48,15 @@ struct sched_clock_data {
*/
raw_spinlock_t lock;
- unsigned long prev_jiffies;
+ unsigned long tick_jiffies;
u64 prev_raw;
u64 tick_raw;
u64 tick_gtod;
u64 clock;
+ s64 multi;
+#ifdef CONFIG_NO_HZ
+ int check_max;
+#endif
};
static DEFINE_PER_CPU_SHARED_ALIGNED(struct sched_clock_data, sched_clock_data);
@@ -71,41 +83,91 @@ void sched_clock_init(void)
struct sched_clock_data *scd = cpu_sdc(cpu);
scd->lock = (raw_spinlock_t)__RAW_SPIN_LOCK_UNLOCKED;
- scd->prev_jiffies = now_jiffies;
+ scd->tick_jiffies = now_jiffies;
scd->prev_raw = 0;
scd->tick_raw = 0;
scd->tick_gtod = ktime_now;
scd->clock = ktime_now;
+ scd->multi = 1 << MULTI_SHIFT;
+#ifdef CONFIG_NO_HZ
+ scd->check_max = 1;
+#endif
}
sched_clock_running = 1;
}
+#ifdef CONFIG_NO_HZ
+/*
+ * The dynamic ticks makes the delta jiffies inaccurate. This
+ * prevents us from checking the maximum time update.
+ * Disable the maximum check during stopped ticks.
+ */
+void sched_clock_tick_stop(int cpu)
+{
+ struct sched_clock_data *scd = cpu_sdc(cpu);
+
+ scd->check_max = 0;
+}
+
+void sched_clock_tick_start(int cpu)
+{
+ struct sched_clock_data *scd = cpu_sdc(cpu);
+
+ scd->check_max = 1;
+}
+
+static int check_max(struct sched_clock_data *scd)
+{
+ return scd->check_max;
+}
+#else
+static int check_max(struct sched_clock_data *scd)
+{
+ return 1;
+}
+#endif /* CONFIG_NO_HZ */
+
/*
* update the percpu scd from the raw @now value
*
* - filter out backward motion
* - use jiffies to generate a min,max window to clip the raw values
*/
-static void __update_sched_clock(struct sched_clock_data *scd, u64 now)
+static void __update_sched_clock(struct sched_clock_data *scd, u64 now, u64 *time)
{
unsigned long now_jiffies = jiffies;
- long delta_jiffies = now_jiffies - scd->prev_jiffies;
+ long delta_jiffies = now_jiffies - scd->tick_jiffies;
u64 clock = scd->clock;
u64 min_clock, max_clock;
s64 delta = now - scd->prev_raw;
WARN_ON_ONCE(!irqs_disabled());
- min_clock = scd->tick_gtod + delta_jiffies * TICK_NSEC;
+
+ /*
+ * At schedule tick the clock can be just under the gtod. We don't
+ * want to push it too prematurely.
+ */
+ min_clock = scd->tick_gtod + (delta_jiffies * TICK_NSEC);
+ if (min_clock > TICK_NSEC)
+ min_clock -= TICK_NSEC / 2;
if (unlikely(delta < 0)) {
clock++;
goto out;
}
- max_clock = min_clock + TICK_NSEC;
+ /*
+ * The clock must stay within a jiffie of the gtod.
+ * But since we may be at the start of a jiffy or the end of one
+ * we add another jiffy buffer.
+ */
+ max_clock = scd->tick_gtod + (2 + delta_jiffies) * TICK_NSEC;
+
+ delta *= scd->multi;
+ delta >>= MULTI_SHIFT;
- if (unlikely(clock + delta > max_clock)) {
+ if (unlikely(clock + delta > max_clock) && check_max(scd)) {
if (clock < max_clock)
clock = max_clock;
else
@@ -118,9 +180,12 @@ static void __update_sched_clock(struct sched_clock_data *scd, u64 now)
if (unlikely(clock < min_clock))
clock = min_clock;
- scd->prev_raw = now;
- scd->prev_jiffies = now_jiffies;
- scd->clock = clock;
+ if (time)
+ *time = clock;
+ else {
+ scd->prev_raw = now;
+ scd->clock = clock;
+ }
}
static void lock_double_clock(struct sched_clock_data *data1,
@@ -160,25 +225,30 @@ u64 sched_clock_cpu(int cpu)
now -= my_scd->tick_raw;
now += scd->tick_raw;
- now -= my_scd->tick_gtod;
- now += scd->tick_gtod;
+ now += my_scd->tick_gtod;
+ now -= scd->tick_gtod;
__raw_spin_unlock(&my_scd->lock);
+
+ __update_sched_clock(scd, now, &clock);
+
+ __raw_spin_unlock(&scd->lock);
+
} else {
__raw_spin_lock(&scd->lock);
+ __update_sched_clock(scd, now, NULL);
+ clock = scd->clock;
+ __raw_spin_unlock(&scd->lock);
}
- __update_sched_clock(scd, now);
- clock = scd->clock;
-
- __raw_spin_unlock(&scd->lock);
-
return clock;
}
void sched_clock_tick(void)
{
struct sched_clock_data *scd = this_scd();
+ unsigned long now_jiffies = jiffies;
+ s64 mult, delta_gtod, delta_raw;
u64 now, now_gtod;
if (unlikely(!sched_clock_running))
@@ -186,18 +256,33 @@ void sched_clock_tick(void)
WARN_ON_ONCE(!irqs_disabled());
- now = sched_clock();
now_gtod = ktime_to_ns(ktime_get());
+ now = sched_clock();
__raw_spin_lock(&scd->lock);
- __update_sched_clock(scd, now);
+ __update_sched_clock(scd, now, NULL);
/*
* update tick_gtod after __update_sched_clock() because that will
* already observe 1 new jiffy; adding a new tick_gtod to that would
* increase the clock 2 jiffies.
*/
+ delta_gtod = now_gtod - scd->tick_gtod;
+ delta_raw = now - scd->tick_raw;
+
+ if ((long)delta_raw > 0) {
+ mult = delta_gtod << MULTI_SHIFT;
+ do_div(mult, delta_raw);
+ scd->multi = mult;
+ if (scd->multi > MAX_MULTI)
+ scd->multi = MAX_MULTI;
+ else if (scd->multi < MIN_MULTI)
+ scd->multi = MIN_MULTI;
+ } else
+ scd->multi = 1 << MULTI_SHIFT;
+
scd->tick_raw = now;
scd->tick_gtod = now_gtod;
+ scd->tick_jiffies = now_jiffies;
__raw_spin_unlock(&scd->lock);
}
@@ -227,6 +312,7 @@ void sched_clock_idle_wakeup_event(u64 delta_ns)
__raw_spin_lock(&scd->lock);
scd->prev_raw = now;
scd->clock += delta_ns;
+ scd->multi = 1 << MULTI_SHIFT;
__raw_spin_unlock(&scd->lock);
touch_softlockup_watchdog();
@@ -244,3 +330,16 @@ unsigned long long __attribute__((weak)) sched_clock(void)
{
return (unsigned long long)jiffies * (NSEC_PER_SEC / HZ);
}
+
+unsigned long long cpu_clock(int cpu)
+{
+ unsigned long long clock;
+ unsigned long flags;
+
+ local_irq_save(flags);
+ clock = sched_clock_cpu(cpu);
+ local_irq_restore(flags);
+
+ return clock;
+}
+EXPORT_SYMBOL_GPL(cpu_clock);
diff --git a/kernel/sched_cpupri.c b/kernel/sched_cpupri.c
new file mode 100644
index 0000000..52154fe
--- /dev/null
+++ b/kernel/sched_cpupri.c
@@ -0,0 +1,174 @@
+/*
+ * kernel/sched_cpupri.c
+ *
+ * CPU priority management
+ *
+ * Copyright (C) 2007-2008 Novell
+ *
+ * Author: Gregory Haskins <ghaskins@...ell.com>
+ *
+ * This code tracks the priority of each CPU so that global migration
+ * decisions are easy to calculate. Each CPU can be in a state as follows:
+ *
+ * (INVALID), IDLE, NORMAL, RT1, ... RT99
+ *
+ * going from the lowest priority to the highest. CPUs in the INVALID state
+ * are not eligible for routing. The system maintains this state with
+ * a 2 dimensional bitmap (the first for priority class, the second for cpus
+ * in that class). Therefore a typical application without affinity
+ * restrictions can find a suitable CPU with O(1) complexity (e.g. two bit
+ * searches). For tasks with affinity restrictions, the algorithm has a
+ * worst case complexity of O(min(102, nr_domcpus)), though the scenario that
+ * yields the worst case search is fairly contrived.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; version 2
+ * of the License.
+ */
+
+#include "sched_cpupri.h"
+
+/* Convert between a 140 based task->prio, and our 102 based cpupri */
+static int convert_prio(int prio)
+{
+ int cpupri;
+
+ if (prio == CPUPRI_INVALID)
+ cpupri = CPUPRI_INVALID;
+ else if (prio == MAX_PRIO)
+ cpupri = CPUPRI_IDLE;
+ else if (prio >= MAX_RT_PRIO)
+ cpupri = CPUPRI_NORMAL;
+ else
+ cpupri = MAX_RT_PRIO - prio + 1;
+
+ return cpupri;
+}
+
+#define for_each_cpupri_active(array, idx) \
+ for (idx = find_first_bit(array, CPUPRI_NR_PRIORITIES); \
+ idx < CPUPRI_NR_PRIORITIES; \
+ idx = find_next_bit(array, CPUPRI_NR_PRIORITIES, idx+1))
+
+/**
+ * cpupri_find - find the best (lowest-pri) CPU in the system
+ * @cp: The cpupri context
+ * @p: The task
+ * @lowest_mask: A mask to fill in with selected CPUs
+ *
+ * Note: This function returns the recommended CPUs as calculated during the
+ * current invokation. By the time the call returns, the CPUs may have in
+ * fact changed priorities any number of times. While not ideal, it is not
+ * an issue of correctness since the normal rebalancer logic will correct
+ * any discrepancies created by racing against the uncertainty of the current
+ * priority configuration.
+ *
+ * Returns: (int)bool - CPUs were found
+ */
+int cpupri_find(struct cpupri *cp, struct task_struct *p,
+ cpumask_t *lowest_mask)
+{
+ int idx = 0;
+ int task_pri = convert_prio(p->prio);
+
+ for_each_cpupri_active(cp->pri_active, idx) {
+ struct cpupri_vec *vec = &cp->pri_to_cpu[idx];
+ cpumask_t mask;
+
+ if (idx >= task_pri)
+ break;
+
+ cpus_and(mask, p->cpus_allowed, vec->mask);
+
+ if (cpus_empty(mask))
+ continue;
+
+ *lowest_mask = mask;
+ return 1;
+ }
+
+ return 0;
+}
+
+/**
+ * cpupri_set - update the cpu priority setting
+ * @cp: The cpupri context
+ * @cpu: The target cpu
+ * @pri: The priority (INVALID-RT99) to assign to this CPU
+ *
+ * Note: Assumes cpu_rq(cpu)->lock is locked
+ *
+ * Returns: (void)
+ */
+void cpupri_set(struct cpupri *cp, int cpu, int newpri)
+{
+ int *currpri = &cp->cpu_to_pri[cpu];
+ int oldpri = *currpri;
+ unsigned long flags;
+
+ newpri = convert_prio(newpri);
+
+ BUG_ON(newpri >= CPUPRI_NR_PRIORITIES);
+
+ if (newpri == oldpri)
+ return;
+
+ /*
+ * If the cpu was currently mapped to a different value, we
+ * first need to unmap the old value
+ */
+ if (likely(oldpri != CPUPRI_INVALID)) {
+ struct cpupri_vec *vec = &cp->pri_to_cpu[oldpri];
+
+ spin_lock_irqsave(&vec->lock, flags);
+
+ vec->count--;
+ if (!vec->count)
+ clear_bit(oldpri, cp->pri_active);
+ cpu_clear(cpu, vec->mask);
+
+ spin_unlock_irqrestore(&vec->lock, flags);
+ }
+
+ if (likely(newpri != CPUPRI_INVALID)) {
+ struct cpupri_vec *vec = &cp->pri_to_cpu[newpri];
+
+ spin_lock_irqsave(&vec->lock, flags);
+
+ cpu_set(cpu, vec->mask);
+ vec->count++;
+ if (vec->count == 1)
+ set_bit(newpri, cp->pri_active);
+
+ spin_unlock_irqrestore(&vec->lock, flags);
+ }
+
+ *currpri = newpri;
+}
+
+/**
+ * cpupri_init - initialize the cpupri structure
+ * @cp: The cpupri context
+ *
+ * Returns: (void)
+ */
+void cpupri_init(struct cpupri *cp)
+{
+ int i;
+
+ memset(cp, 0, sizeof(*cp));
+
+ for (i = 0; i < CPUPRI_NR_PRIORITIES; i++) {
+ struct cpupri_vec *vec = &cp->pri_to_cpu[i];
+
+ spin_lock_init(&vec->lock);
+ vec->count = 0;
+ cpus_clear(vec->mask);
+ }
+
+ for_each_possible_cpu(i)
+ cp->cpu_to_pri[i] = CPUPRI_INVALID;
+}
+
+
diff --git a/kernel/sched_cpupri.h b/kernel/sched_cpupri.h
new file mode 100644
index 0000000..f25811b
--- /dev/null
+++ b/kernel/sched_cpupri.h
@@ -0,0 +1,36 @@
+#ifndef _LINUX_CPUPRI_H
+#define _LINUX_CPUPRI_H
+
+#include <linux/sched.h>
+
+#define CPUPRI_NR_PRIORITIES (MAX_RT_PRIO + 2)
+#define CPUPRI_NR_PRI_WORDS BITS_TO_LONGS(CPUPRI_NR_PRIORITIES)
+
+#define CPUPRI_INVALID -1
+#define CPUPRI_IDLE 0
+#define CPUPRI_NORMAL 1
+/* values 2-101 are RT priorities 0-99 */
+
+struct cpupri_vec {
+ spinlock_t lock;
+ int count;
+ cpumask_t mask;
+};
+
+struct cpupri {
+ struct cpupri_vec pri_to_cpu[CPUPRI_NR_PRIORITIES];
+ long pri_active[CPUPRI_NR_PRI_WORDS];
+ int cpu_to_pri[NR_CPUS];
+};
+
+#ifdef CONFIG_SMP
+int cpupri_find(struct cpupri *cp,
+ struct task_struct *p, cpumask_t *lowest_mask);
+void cpupri_set(struct cpupri *cp, int cpu, int pri);
+void cpupri_init(struct cpupri *cp);
+#else
+#define cpupri_set(cp, cpu, pri) do { } while (0)
+#define cpupri_init() do { } while (0)
+#endif
+
+#endif /* _LINUX_CPUPRI_H */
diff --git a/kernel/sched_debug.c b/kernel/sched_debug.c
index 8bb7130..bbe6b31 100644
--- a/kernel/sched_debug.c
+++ b/kernel/sched_debug.c
@@ -119,9 +119,7 @@ void print_cfs_rq(struct seq_file *m, int cpu, struct cfs_rq *cfs_rq)
struct sched_entity *last;
unsigned long flags;
-#if !defined(CONFIG_CGROUP_SCHED) || !defined(CONFIG_USER_SCHED)
- SEQ_printf(m, "\ncfs_rq[%d]:\n", cpu);
-#else
+#if defined(CONFIG_CGROUP_SCHED) && defined(CONFIG_FAIR_GROUP_SCHED)
char path[128] = "";
struct cgroup *cgroup = NULL;
struct task_group *tg = cfs_rq->tg;
@@ -133,6 +131,8 @@ void print_cfs_rq(struct seq_file *m, int cpu, struct cfs_rq *cfs_rq)
cgroup_path(cgroup, path, sizeof(path));
SEQ_printf(m, "\ncfs_rq[%d]:%s\n", cpu, path);
+#else
+ SEQ_printf(m, "\ncfs_rq[%d]:\n", cpu);
#endif
SEQ_printf(m, " .%-30s: %Ld.%06ld\n", "exec_clock",
@@ -162,11 +162,64 @@ void print_cfs_rq(struct seq_file *m, int cpu, struct cfs_rq *cfs_rq)
SEQ_printf(m, " .%-30s: %ld\n", "nr_running", cfs_rq->nr_running);
SEQ_printf(m, " .%-30s: %ld\n", "load", cfs_rq->load.weight);
#ifdef CONFIG_SCHEDSTATS
- SEQ_printf(m, " .%-30s: %d\n", "bkl_count",
- rq->bkl_count);
+#define P(n) SEQ_printf(m, " .%-30s: %d\n", #n, rq->n);
+
+ P(yld_exp_empty);
+ P(yld_act_empty);
+ P(yld_both_empty);
+ P(yld_count);
+
+ P(sched_switch);
+ P(sched_count);
+ P(sched_goidle);
+
+ P(ttwu_count);
+ P(ttwu_local);
+
+ P(bkl_count);
+
+#undef P
#endif
SEQ_printf(m, " .%-30s: %ld\n", "nr_spread_over",
cfs_rq->nr_spread_over);
+#ifdef CONFIG_FAIR_GROUP_SCHED
+#ifdef CONFIG_SMP
+ SEQ_printf(m, " .%-30s: %lu\n", "shares", cfs_rq->shares);
+#endif
+#endif
+}
+
+void print_rt_rq(struct seq_file *m, int cpu, struct rt_rq *rt_rq)
+{
+#if defined(CONFIG_CGROUP_SCHED) && defined(CONFIG_RT_GROUP_SCHED)
+ char path[128] = "";
+ struct cgroup *cgroup = NULL;
+ struct task_group *tg = rt_rq->tg;
+
+ if (tg)
+ cgroup = tg->css.cgroup;
+
+ if (cgroup)
+ cgroup_path(cgroup, path, sizeof(path));
+
+ SEQ_printf(m, "\nrt_rq[%d]:%s\n", cpu, path);
+#else
+ SEQ_printf(m, "\nrt_rq[%d]:\n", cpu);
+#endif
+
+
+#define P(x) \
+ SEQ_printf(m, " .%-30s: %Ld\n", #x, (long long)(rt_rq->x))
+#define PN(x) \
+ SEQ_printf(m, " .%-30s: %Ld.%06ld\n", #x, SPLIT_NS(rt_rq->x))
+
+ P(rt_nr_running);
+ P(rt_throttled);
+ PN(rt_time);
+ PN(rt_runtime);
+
+#undef PN
+#undef P
}
static void print_cpu(struct seq_file *m, int cpu)
@@ -208,6 +261,7 @@ static void print_cpu(struct seq_file *m, int cpu)
#undef PN
print_cfs_stats(m, cpu);
+ print_rt_stats(m, cpu);
print_rq(m, rq, cpu);
}
diff --git a/kernel/sched_fair.c b/kernel/sched_fair.c
index 08ae848..f2aa987 100644
--- a/kernel/sched_fair.c
+++ b/kernel/sched_fair.c
@@ -63,13 +63,13 @@ unsigned int __read_mostly sysctl_sched_compat_yield;
/*
* SCHED_OTHER wake-up granularity.
- * (default: 10 msec * (1 + ilog(ncpus)), units: nanoseconds)
+ * (default: 5 msec * (1 + ilog(ncpus)), units: nanoseconds)
*
* This option delays the preemption effects of decoupled workloads
* and reduces their over-scheduling. Synchronous workloads will still
* have immediate wakeup/sleep latencies.
*/
-unsigned int sysctl_sched_wakeup_granularity = 10000000UL;
+unsigned int sysctl_sched_wakeup_granularity = 5000000UL;
const_debug unsigned int sysctl_sched_migration_cost = 500000UL;
@@ -334,6 +334,34 @@ int sched_nr_latency_handler(struct ctl_table *table, int write,
#endif
/*
+ * delta *= w / rw
+ */
+static inline unsigned long
+calc_delta_weight(unsigned long delta, struct sched_entity *se)
+{
+ for_each_sched_entity(se) {
+ delta = calc_delta_mine(delta,
+ se->load.weight, &cfs_rq_of(se)->load);
+ }
+
+ return delta;
+}
+
+/*
+ * delta *= rw / w
+ */
+static inline unsigned long
+calc_delta_fair(unsigned long delta, struct sched_entity *se)
+{
+ for_each_sched_entity(se) {
+ delta = calc_delta_mine(delta,
+ cfs_rq_of(se)->load.weight, &se->load);
+ }
+
+ return delta;
+}
+
+/*
* The idea is to set a period in which each task runs once.
*
* When there are too many tasks (sysctl_sched_nr_latency) we have to stretch
@@ -362,47 +390,80 @@ static u64 __sched_period(unsigned long nr_running)
*/
static u64 sched_slice(struct cfs_rq *cfs_rq, struct sched_entity *se)
{
- u64 slice = __sched_period(cfs_rq->nr_running);
-
- for_each_sched_entity(se) {
- cfs_rq = cfs_rq_of(se);
-
- slice *= se->load.weight;
- do_div(slice, cfs_rq->load.weight);
- }
-
-
- return slice;
+ return calc_delta_weight(__sched_period(cfs_rq->nr_running), se);
}
/*
* We calculate the vruntime slice of a to be inserted task
*
- * vs = s/w = p/rw
+ * vs = s*rw/w = p
*/
static u64 sched_vslice_add(struct cfs_rq *cfs_rq, struct sched_entity *se)
{
unsigned long nr_running = cfs_rq->nr_running;
- unsigned long weight;
- u64 vslice;
if (!se->on_rq)
nr_running++;
- vslice = __sched_period(nr_running);
+ return __sched_period(nr_running);
+}
+
+/*
+ * The goal of calc_delta_asym() is to be asymmetrically around NICE_0_LOAD, in
+ * that it favours >=0 over <0.
+ *
+ * -20 |
+ * |
+ * 0 --------+-------
+ * .'
+ * 19 .'
+ *
+ */
+static unsigned long
+calc_delta_asym(unsigned long delta, struct sched_entity *se)
+{
+ struct load_weight lw = {
+ .weight = NICE_0_LOAD,
+ .inv_weight = 1UL << (WMULT_SHIFT-NICE_0_SHIFT)
+ };
for_each_sched_entity(se) {
- cfs_rq = cfs_rq_of(se);
+ struct load_weight *se_lw = &se->load;
+ unsigned long rw = cfs_rq_of(se)->load.weight;
+
+#ifdef CONFIG_FAIR_SCHED_GROUP
+ struct cfs_rq *cfs_rq = se->my_q;
+ struct task_group *tg = NULL
+
+ if (cfs_rq)
+ tg = cfs_rq->tg;
+
+ if (tg && tg->shares < NICE_0_LOAD) {
+ /*
+ * scale shares to what it would have been had
+ * tg->weight been NICE_0_LOAD:
+ *
+ * weight = 1024 * shares / tg->weight
+ */
+ lw.weight *= se->load.weight;
+ lw.weight /= tg->shares;
+
+ lw.inv_weight = 0;
+
+ se_lw = &lw;
+ rw += lw.weight - se->load.weight;
+ } else
+#endif
- weight = cfs_rq->load.weight;
- if (!se->on_rq)
- weight += se->load.weight;
+ if (se->load.weight < NICE_0_LOAD) {
+ se_lw = &lw;
+ rw += NICE_0_LOAD - se->load.weight;
+ }
- vslice *= NICE_0_LOAD;
- do_div(vslice, weight);
+ delta = calc_delta_mine(delta, rw, se_lw);
}
- return vslice;
+ return delta;
}
/*
@@ -419,11 +480,7 @@ __update_curr(struct cfs_rq *cfs_rq, struct sched_entity *curr,
curr->sum_exec_runtime += delta_exec;
schedstat_add(cfs_rq, exec_clock, delta_exec);
- delta_exec_weighted = delta_exec;
- if (unlikely(curr->load.weight != NICE_0_LOAD)) {
- delta_exec_weighted = calc_delta_fair(delta_exec_weighted,
- &curr->load);
- }
+ delta_exec_weighted = calc_delta_fair(delta_exec, curr);
curr->vruntime += delta_exec_weighted;
}
@@ -510,10 +567,27 @@ update_stats_curr_start(struct cfs_rq *cfs_rq, struct sched_entity *se)
* Scheduling class queueing methods:
*/
+#if defined CONFIG_SMP && defined CONFIG_FAIR_GROUP_SCHED
+static void
+add_cfs_task_weight(struct cfs_rq *cfs_rq, unsigned long weight)
+{
+ cfs_rq->task_weight += weight;
+}
+#else
+static inline void
+add_cfs_task_weight(struct cfs_rq *cfs_rq, unsigned long weight)
+{
+}
+#endif
+
static void
account_entity_enqueue(struct cfs_rq *cfs_rq, struct sched_entity *se)
{
update_load_add(&cfs_rq->load, se->load.weight);
+ if (!parent_entity(se))
+ inc_cpu_load(rq_of(cfs_rq), se->load.weight);
+ if (entity_is_task(se))
+ add_cfs_task_weight(cfs_rq, se->load.weight);
cfs_rq->nr_running++;
se->on_rq = 1;
list_add(&se->group_node, &cfs_rq->tasks);
@@ -523,6 +597,10 @@ static void
account_entity_dequeue(struct cfs_rq *cfs_rq, struct sched_entity *se)
{
update_load_sub(&cfs_rq->load, se->load.weight);
+ if (!parent_entity(se))
+ dec_cpu_load(rq_of(cfs_rq), se->load.weight);
+ if (entity_is_task(se))
+ add_cfs_task_weight(cfs_rq, -se->load.weight);
cfs_rq->nr_running--;
se->on_rq = 0;
list_del_init(&se->group_node);
@@ -609,8 +687,17 @@ place_entity(struct cfs_rq *cfs_rq, struct sched_entity *se, int initial)
if (!initial) {
/* sleeps upto a single latency don't count. */
- if (sched_feat(NEW_FAIR_SLEEPERS))
- vruntime -= sysctl_sched_latency;
+ if (sched_feat(NEW_FAIR_SLEEPERS)) {
+ unsigned long thresh = sysctl_sched_latency;
+
+ /*
+ * convert the sleeper threshold into virtual time
+ */
+ if (sched_feat(NORMALIZED_SLEEPER))
+ thresh = calc_delta_fair(thresh, se);
+
+ vruntime -= thresh;
+ }
/* ensure we never gain time by being placed backwards. */
vruntime = max_vruntime(se->vruntime, vruntime);
@@ -639,21 +726,6 @@ enqueue_entity(struct cfs_rq *cfs_rq, struct sched_entity *se, int wakeup)
__enqueue_entity(cfs_rq, se);
}
-static void update_avg(u64 *avg, u64 sample)
-{
- s64 diff = sample - *avg;
- *avg += diff >> 3;
-}
-
-static void update_avg_stats(struct cfs_rq *cfs_rq, struct sched_entity *se)
-{
- if (!se->last_wakeup)
- return;
-
- update_avg(&se->avg_overlap, se->sum_exec_runtime - se->last_wakeup);
- se->last_wakeup = 0;
-}
-
static void
dequeue_entity(struct cfs_rq *cfs_rq, struct sched_entity *se, int sleep)
{
@@ -664,7 +736,6 @@ dequeue_entity(struct cfs_rq *cfs_rq, struct sched_entity *se, int sleep)
update_stats_dequeue(cfs_rq, se);
if (sleep) {
- update_avg_stats(cfs_rq, se);
#ifdef CONFIG_SCHEDSTATS
if (entity_is_task(se)) {
struct task_struct *tsk = task_of(se);
@@ -726,17 +797,16 @@ set_next_entity(struct cfs_rq *cfs_rq, struct sched_entity *se)
se->prev_sum_exec_runtime = se->sum_exec_runtime;
}
-static int
-wakeup_preempt_entity(struct sched_entity *curr, struct sched_entity *se);
-
static struct sched_entity *
pick_next(struct cfs_rq *cfs_rq, struct sched_entity *se)
{
- if (!cfs_rq->next)
- return se;
+ struct rq *rq = rq_of(cfs_rq);
+ u64 pair_slice = rq->clock - cfs_rq->pair_start;
- if (wakeup_preempt_entity(cfs_rq->next, se) != 0)
+ if (!cfs_rq->next || pair_slice > sched_slice(cfs_rq, cfs_rq->next)) {
+ cfs_rq->pair_start = rq->clock;
return se;
+ }
return cfs_rq->next;
}
@@ -835,7 +905,7 @@ static void hrtick_start_fair(struct rq *rq, struct task_struct *p)
hrtick_start(rq, delta, requeue);
}
}
-#else
+#else /* !CONFIG_SCHED_HRTICK */
static inline void
hrtick_start_fair(struct rq *rq, struct task_struct *p)
{
@@ -976,7 +1046,7 @@ static int wake_idle(int cpu, struct task_struct *p)
}
return cpu;
}
-#else
+#else /* !ARCH_HAS_SCHED_WAKE_IDLE*/
static inline int wake_idle(int cpu, struct task_struct *p)
{
return cpu;
@@ -987,6 +1057,89 @@ static inline int wake_idle(int cpu, struct task_struct *p)
static const struct sched_class fair_sched_class;
+#ifdef CONFIG_FAIR_GROUP_SCHED
+/*
+ * effective_load() calculates the load change as seen from the root_task_group
+ *
+ * Adding load to a group doesn't make a group heavier, but can cause movement
+ * of group shares between cpus. Assuming the shares were perfectly aligned one
+ * can calculate the shift in shares.
+ *
+ * The problem is that perfectly aligning the shares is rather expensive, hence
+ * we try to avoid doing that too often - see update_shares(), which ratelimits
+ * this change.
+ *
+ * We compensate this by not only taking the current delta into account, but
+ * also considering the delta between when the shares were last adjusted and
+ * now.
+ *
+ * We still saw a performance dip, some tracing learned us that between
+ * cgroup:/ and cgroup:/foo balancing the number of affine wakeups increased
+ * significantly. Therefore try to bias the error in direction of failing
+ * the affine wakeup.
+ *
+ */
+static long effective_load(struct task_group *tg, int cpu,
+ long wl, long wg)
+{
+ struct sched_entity *se = tg->se[cpu];
+ long more_w;
+
+ if (!tg->parent)
+ return wl;
+
+ /*
+ * By not taking the decrease of shares on the other cpu into
+ * account our error leans towards reducing the affine wakeups.
+ */
+ if (!wl && sched_feat(ASYM_EFF_LOAD))
+ return wl;
+
+ /*
+ * Instead of using this increment, also add the difference
+ * between when the shares were last updated and now.
+ */
+ more_w = se->my_q->load.weight - se->my_q->rq_weight;
+ wl += more_w;
+ wg += more_w;
+
+ for_each_sched_entity(se) {
+#define D(n) (likely(n) ? (n) : 1)
+
+ long S, rw, s, a, b;
+
+ S = se->my_q->tg->shares;
+ s = se->my_q->shares;
+ rw = se->my_q->rq_weight;
+
+ a = S*(rw + wl);
+ b = S*rw + s*wg;
+
+ wl = s*(a-b)/D(b);
+ /*
+ * Assume the group is already running and will
+ * thus already be accounted for in the weight.
+ *
+ * That is, moving shares between CPUs, does not
+ * alter the group weight.
+ */
+ wg = 0;
+#undef D
+ }
+
+ return wl;
+}
+
+#else
+
+static inline unsigned long effective_load(struct task_group *tg, int cpu,
+ unsigned long wl, unsigned long wg)
+{
+ return wl;
+}
+
+#endif
+
static int
wake_affine(struct rq *rq, struct sched_domain *this_sd, struct rq *this_rq,
struct task_struct *p, int prev_cpu, int this_cpu, int sync,
@@ -994,8 +1147,10 @@ wake_affine(struct rq *rq, struct sched_domain *this_sd, struct rq *this_rq,
unsigned int imbalance)
{
struct task_struct *curr = this_rq->curr;
+ struct task_group *tg;
unsigned long tl = this_load;
unsigned long tl_per_task;
+ unsigned long weight;
int balanced;
if (!(this_sd->flags & SD_WAKE_AFFINE) || !sched_feat(AFFINE_WAKEUPS))
@@ -1006,19 +1161,28 @@ wake_affine(struct rq *rq, struct sched_domain *this_sd, struct rq *this_rq,
* effect of the currently running task from the load
* of the current CPU:
*/
- if (sync)
- tl -= current->se.load.weight;
+ if (sync) {
+ tg = task_group(current);
+ weight = current->se.load.weight;
+
+ tl += effective_load(tg, this_cpu, -weight, -weight);
+ load += effective_load(tg, prev_cpu, 0, -weight);
+ }
- balanced = 100*(tl + p->se.load.weight) <= imbalance*load;
+ tg = task_group(p);
+ weight = p->se.load.weight;
+
+ balanced = 100*(tl + effective_load(tg, this_cpu, weight, weight)) <=
+ imbalance*(load + effective_load(tg, prev_cpu, 0, weight));
/*
* If the currently running task will sleep within
* a reasonable amount of time then attract this newly
* woken task:
*/
- if (sync && balanced && curr->sched_class == &fair_sched_class) {
+ if (sync && balanced) {
if (curr->se.avg_overlap < sysctl_sched_migration_cost &&
- p->se.avg_overlap < sysctl_sched_migration_cost)
+ p->se.avg_overlap < sysctl_sched_migration_cost)
return 1;
}
@@ -1111,11 +1275,13 @@ static unsigned long wakeup_gran(struct sched_entity *se)
unsigned long gran = sysctl_sched_wakeup_granularity;
/*
- * More easily preempt - nice tasks, while not making
- * it harder for + nice tasks.
+ * More easily preempt - nice tasks, while not making it harder for
+ * + nice tasks.
*/
- if (unlikely(se->load.weight > NICE_0_LOAD))
- gran = calc_delta_fair(gran, &se->load);
+ if (sched_feat(ASYM_GRAN))
+ gran = calc_delta_asym(sysctl_sched_wakeup_granularity, se);
+ else
+ gran = calc_delta_fair(sysctl_sched_wakeup_granularity, se);
return gran;
}
@@ -1177,7 +1343,6 @@ static void check_preempt_wakeup(struct rq *rq, struct task_struct *p)
return;
}
- se->last_wakeup = se->sum_exec_runtime;
if (unlikely(se == pse))
return;
@@ -1275,23 +1440,18 @@ __load_balance_iterator(struct cfs_rq *cfs_rq, struct list_head *next)
struct task_struct *p = NULL;
struct sched_entity *se;
- if (next == &cfs_rq->tasks)
- return NULL;
-
- /* Skip over entities that are not tasks */
- do {
+ while (next != &cfs_rq->tasks) {
se = list_entry(next, struct sched_entity, group_node);
next = next->next;
- } while (next != &cfs_rq->tasks && !entity_is_task(se));
- if (next == &cfs_rq->tasks)
- return NULL;
+ /* Skip over entities that are not tasks */
+ if (entity_is_task(se)) {
+ p = task_of(se);
+ break;
+ }
+ }
cfs_rq->balance_iterator = next;
-
- if (entity_is_task(se))
- p = task_of(se);
-
return p;
}
@@ -1309,75 +1469,82 @@ static struct task_struct *load_balance_next_fair(void *arg)
return __load_balance_iterator(cfs_rq, cfs_rq->balance_iterator);
}
-#ifdef CONFIG_FAIR_GROUP_SCHED
-static int cfs_rq_best_prio(struct cfs_rq *cfs_rq)
+static unsigned long
+__load_balance_fair(struct rq *this_rq, int this_cpu, struct rq *busiest,
+ unsigned long max_load_move, struct sched_domain *sd,
+ enum cpu_idle_type idle, int *all_pinned, int *this_best_prio,
+ struct cfs_rq *cfs_rq)
{
- struct sched_entity *curr;
- struct task_struct *p;
-
- if (!cfs_rq->nr_running || !first_fair(cfs_rq))
- return MAX_PRIO;
-
- curr = cfs_rq->curr;
- if (!curr)
- curr = __pick_next_entity(cfs_rq);
+ struct rq_iterator cfs_rq_iterator;
- p = task_of(curr);
+ cfs_rq_iterator.start = load_balance_start_fair;
+ cfs_rq_iterator.next = load_balance_next_fair;
+ cfs_rq_iterator.arg = cfs_rq;
- return p->prio;
+ return balance_tasks(this_rq, this_cpu, busiest,
+ max_load_move, sd, idle, all_pinned,
+ this_best_prio, &cfs_rq_iterator);
}
-#endif
+#ifdef CONFIG_FAIR_GROUP_SCHED
static unsigned long
load_balance_fair(struct rq *this_rq, int this_cpu, struct rq *busiest,
unsigned long max_load_move,
struct sched_domain *sd, enum cpu_idle_type idle,
int *all_pinned, int *this_best_prio)
{
- struct cfs_rq *busy_cfs_rq;
long rem_load_move = max_load_move;
- struct rq_iterator cfs_rq_iterator;
-
- cfs_rq_iterator.start = load_balance_start_fair;
- cfs_rq_iterator.next = load_balance_next_fair;
+ int busiest_cpu = cpu_of(busiest);
+ struct task_group *tg;
- for_each_leaf_cfs_rq(busiest, busy_cfs_rq) {
-#ifdef CONFIG_FAIR_GROUP_SCHED
- struct cfs_rq *this_cfs_rq;
- long imbalance;
- unsigned long maxload;
+ rcu_read_lock();
+ update_h_load(busiest_cpu);
- this_cfs_rq = cpu_cfs_rq(busy_cfs_rq, this_cpu);
+ list_for_each_entry(tg, &task_groups, list) {
+ struct cfs_rq *busiest_cfs_rq = tg->cfs_rq[busiest_cpu];
+ unsigned long busiest_h_load = busiest_cfs_rq->h_load;
+ unsigned long busiest_weight = busiest_cfs_rq->load.weight;
+ u64 rem_load, moved_load;
- imbalance = busy_cfs_rq->load.weight - this_cfs_rq->load.weight;
- /* Don't pull if this_cfs_rq has more load than busy_cfs_rq */
- if (imbalance <= 0)
+ /*
+ * empty group
+ */
+ if (!busiest_cfs_rq->task_weight)
continue;
- /* Don't pull more than imbalance/2 */
- imbalance /= 2;
- maxload = min(rem_load_move, imbalance);
+ rem_load = (u64)rem_load_move * busiest_weight;
+ rem_load = div_u64(rem_load, busiest_h_load + 1);
- *this_best_prio = cfs_rq_best_prio(this_cfs_rq);
-#else
-# define maxload rem_load_move
-#endif
- /*
- * pass busy_cfs_rq argument into
- * load_balance_[start|next]_fair iterators
- */
- cfs_rq_iterator.arg = busy_cfs_rq;
- rem_load_move -= balance_tasks(this_rq, this_cpu, busiest,
- maxload, sd, idle, all_pinned,
- this_best_prio,
- &cfs_rq_iterator);
+ moved_load = __load_balance_fair(this_rq, this_cpu, busiest,
+ rem_load, sd, idle, all_pinned, this_best_prio,
+ tg->cfs_rq[busiest_cpu]);
+
+ if (!moved_load)
+ continue;
+
+ moved_load *= busiest_h_load;
+ moved_load = div_u64(moved_load, busiest_weight + 1);
- if (rem_load_move <= 0)
+ rem_load_move -= moved_load;
+ if (rem_load_move < 0)
break;
}
+ rcu_read_unlock();
return max_load_move - rem_load_move;
}
+#else
+static unsigned long
+load_balance_fair(struct rq *this_rq, int this_cpu, struct rq *busiest,
+ unsigned long max_load_move,
+ struct sched_domain *sd, enum cpu_idle_type idle,
+ int *all_pinned, int *this_best_prio)
+{
+ return __load_balance_fair(this_rq, this_cpu, busiest,
+ max_load_move, sd, idle, all_pinned,
+ this_best_prio, &busiest->cfs);
+}
+#endif
static int
move_one_task_fair(struct rq *this_rq, int this_cpu, struct rq *busiest,
@@ -1402,7 +1569,7 @@ move_one_task_fair(struct rq *this_rq, int this_cpu, struct rq *busiest,
return 0;
}
-#endif
+#endif /* CONFIG_SMP */
/*
* scheduler tick hitting a task of our scheduling class:
diff --git a/kernel/sched_features.h b/kernel/sched_features.h
index 1c7283c..862b06b 100644
--- a/kernel/sched_features.h
+++ b/kernel/sched_features.h
@@ -1,4 +1,5 @@
SCHED_FEAT(NEW_FAIR_SLEEPERS, 1)
+SCHED_FEAT(NORMALIZED_SLEEPER, 1)
SCHED_FEAT(WAKEUP_PREEMPT, 1)
SCHED_FEAT(START_DEBIT, 1)
SCHED_FEAT(AFFINE_WAKEUPS, 1)
@@ -6,5 +7,7 @@ SCHED_FEAT(CACHE_HOT_BUDDY, 1)
SCHED_FEAT(SYNC_WAKEUPS, 1)
SCHED_FEAT(HRTICK, 1)
SCHED_FEAT(DOUBLE_TICK, 0)
-SCHED_FEAT(NORMALIZED_SLEEPER, 1)
-SCHED_FEAT(DEADLINE, 1)
+SCHED_FEAT(ASYM_GRAN, 1)
+SCHED_FEAT(LB_BIAS, 0)
+SCHED_FEAT(LB_WAKEUP_UPDATE, 1)
+SCHED_FEAT(ASYM_EFF_LOAD, 1)
diff --git a/kernel/sched_rt.c b/kernel/sched_rt.c
index 0f3c191..47ceac9 100644
--- a/kernel/sched_rt.c
+++ b/kernel/sched_rt.c
@@ -12,6 +12,9 @@ static inline int rt_overloaded(struct rq *rq)
static inline void rt_set_overload(struct rq *rq)
{
+ if (!rq->online)
+ return;
+
cpu_set(rq->cpu, rq->rd->rto_mask);
/*
* Make sure the mask is visible before we set
@@ -26,6 +29,9 @@ static inline void rt_set_overload(struct rq *rq)
static inline void rt_clear_overload(struct rq *rq)
{
+ if (!rq->online)
+ return;
+
/* the order here really doesn't matter */
atomic_dec(&rq->rd->rto_count);
cpu_clear(rq->cpu, rq->rd->rto_mask);
@@ -155,7 +161,7 @@ static inline struct rt_bandwidth *sched_rt_bandwidth(struct rt_rq *rt_rq)
return &rt_rq->tg->rt_bandwidth;
}
-#else
+#else /* !CONFIG_RT_GROUP_SCHED */
static inline u64 sched_rt_runtime(struct rt_rq *rt_rq)
{
@@ -220,49 +226,10 @@ static inline struct rt_bandwidth *sched_rt_bandwidth(struct rt_rq *rt_rq)
return &def_rt_bandwidth;
}
-#endif
-
-static int do_sched_rt_period_timer(struct rt_bandwidth *rt_b, int overrun)
-{
- int i, idle = 1;
- cpumask_t span;
-
- if (rt_b->rt_runtime == RUNTIME_INF)
- return 1;
-
- span = sched_rt_period_mask();
- for_each_cpu_mask(i, span) {
- int enqueue = 0;
- struct rt_rq *rt_rq = sched_rt_period_rt_rq(rt_b, i);
- struct rq *rq = rq_of_rt_rq(rt_rq);
-
- spin_lock(&rq->lock);
- if (rt_rq->rt_time) {
- u64 runtime;
-
- spin_lock(&rt_rq->rt_runtime_lock);
- runtime = rt_rq->rt_runtime;
- rt_rq->rt_time -= min(rt_rq->rt_time, overrun*runtime);
- if (rt_rq->rt_throttled && rt_rq->rt_time < runtime) {
- rt_rq->rt_throttled = 0;
- enqueue = 1;
- }
- if (rt_rq->rt_time || rt_rq->rt_nr_running)
- idle = 0;
- spin_unlock(&rt_rq->rt_runtime_lock);
- } else if (rt_rq->rt_nr_running)
- idle = 0;
-
- if (enqueue)
- sched_rt_rq_enqueue(rt_rq);
- spin_unlock(&rq->lock);
- }
-
- return idle;
-}
+#endif /* CONFIG_RT_GROUP_SCHED */
#ifdef CONFIG_SMP
-static int balance_runtime(struct rt_rq *rt_rq)
+static int do_balance_runtime(struct rt_rq *rt_rq)
{
struct rt_bandwidth *rt_b = sched_rt_bandwidth(rt_rq);
struct root_domain *rd = cpu_rq(smp_processor_id())->rd;
@@ -281,6 +248,9 @@ static int balance_runtime(struct rt_rq *rt_rq)
continue;
spin_lock(&iter->rt_runtime_lock);
+ if (iter->rt_runtime == RUNTIME_INF)
+ goto next;
+
diff = iter->rt_runtime - iter->rt_time;
if (diff > 0) {
do_div(diff, weight);
@@ -294,13 +264,163 @@ static int balance_runtime(struct rt_rq *rt_rq)
break;
}
}
+next:
spin_unlock(&iter->rt_runtime_lock);
}
spin_unlock(&rt_b->rt_runtime_lock);
return more;
}
-#endif
+
+static void __disable_runtime(struct rq *rq)
+{
+ struct root_domain *rd = rq->rd;
+ struct rt_rq *rt_rq;
+
+ if (unlikely(!scheduler_running))
+ return;
+
+ for_each_leaf_rt_rq(rt_rq, rq) {
+ struct rt_bandwidth *rt_b = sched_rt_bandwidth(rt_rq);
+ s64 want;
+ int i;
+
+ spin_lock(&rt_b->rt_runtime_lock);
+ spin_lock(&rt_rq->rt_runtime_lock);
+ if (rt_rq->rt_runtime == RUNTIME_INF ||
+ rt_rq->rt_runtime == rt_b->rt_runtime)
+ goto balanced;
+ spin_unlock(&rt_rq->rt_runtime_lock);
+
+ want = rt_b->rt_runtime - rt_rq->rt_runtime;
+
+ for_each_cpu_mask(i, rd->span) {
+ struct rt_rq *iter = sched_rt_period_rt_rq(rt_b, i);
+ s64 diff;
+
+ if (iter == rt_rq)
+ continue;
+
+ spin_lock(&iter->rt_runtime_lock);
+ if (want > 0) {
+ diff = min_t(s64, iter->rt_runtime, want);
+ iter->rt_runtime -= diff;
+ want -= diff;
+ } else {
+ iter->rt_runtime -= want;
+ want -= want;
+ }
+ spin_unlock(&iter->rt_runtime_lock);
+
+ if (!want)
+ break;
+ }
+
+ spin_lock(&rt_rq->rt_runtime_lock);
+ BUG_ON(want);
+balanced:
+ rt_rq->rt_runtime = RUNTIME_INF;
+ spin_unlock(&rt_rq->rt_runtime_lock);
+ spin_unlock(&rt_b->rt_runtime_lock);
+ }
+}
+
+static void disable_runtime(struct rq *rq)
+{
+ unsigned long flags;
+
+ spin_lock_irqsave(&rq->lock, flags);
+ __disable_runtime(rq);
+ spin_unlock_irqrestore(&rq->lock, flags);
+}
+
+static void __enable_runtime(struct rq *rq)
+{
+ struct rt_rq *rt_rq;
+
+ if (unlikely(!scheduler_running))
+ return;
+
+ for_each_leaf_rt_rq(rt_rq, rq) {
+ struct rt_bandwidth *rt_b = sched_rt_bandwidth(rt_rq);
+
+ spin_lock(&rt_b->rt_runtime_lock);
+ spin_lock(&rt_rq->rt_runtime_lock);
+ rt_rq->rt_runtime = rt_b->rt_runtime;
+ rt_rq->rt_time = 0;
+ spin_unlock(&rt_rq->rt_runtime_lock);
+ spin_unlock(&rt_b->rt_runtime_lock);
+ }
+}
+
+static void enable_runtime(struct rq *rq)
+{
+ unsigned long flags;
+
+ spin_lock_irqsave(&rq->lock, flags);
+ __enable_runtime(rq);
+ spin_unlock_irqrestore(&rq->lock, flags);
+}
+
+static int balance_runtime(struct rt_rq *rt_rq)
+{
+ int more = 0;
+
+ if (rt_rq->rt_time > rt_rq->rt_runtime) {
+ spin_unlock(&rt_rq->rt_runtime_lock);
+ more = do_balance_runtime(rt_rq);
+ spin_lock(&rt_rq->rt_runtime_lock);
+ }
+
+ return more;
+}
+#else /* !CONFIG_SMP */
+static inline int balance_runtime(struct rt_rq *rt_rq)
+{
+ return 0;
+}
+#endif /* CONFIG_SMP */
+
+static int do_sched_rt_period_timer(struct rt_bandwidth *rt_b, int overrun)
+{
+ int i, idle = 1;
+ cpumask_t span;
+
+ if (rt_b->rt_runtime == RUNTIME_INF)
+ return 1;
+
+ span = sched_rt_period_mask();
+ for_each_cpu_mask(i, span) {
+ int enqueue = 0;
+ struct rt_rq *rt_rq = sched_rt_period_rt_rq(rt_b, i);
+ struct rq *rq = rq_of_rt_rq(rt_rq);
+
+ spin_lock(&rq->lock);
+ if (rt_rq->rt_time) {
+ u64 runtime;
+
+ spin_lock(&rt_rq->rt_runtime_lock);
+ if (rt_rq->rt_throttled)
+ balance_runtime(rt_rq);
+ runtime = rt_rq->rt_runtime;
+ rt_rq->rt_time -= min(rt_rq->rt_time, overrun*runtime);
+ if (rt_rq->rt_throttled && rt_rq->rt_time < runtime) {
+ rt_rq->rt_throttled = 0;
+ enqueue = 1;
+ }
+ if (rt_rq->rt_time || rt_rq->rt_nr_running)
+ idle = 0;
+ spin_unlock(&rt_rq->rt_runtime_lock);
+ } else if (rt_rq->rt_nr_running)
+ idle = 0;
+
+ if (enqueue)
+ sched_rt_rq_enqueue(rt_rq);
+ spin_unlock(&rq->lock);
+ }
+
+ return idle;
+}
static inline int rt_se_prio(struct sched_rt_entity *rt_se)
{
@@ -327,18 +447,10 @@ static int sched_rt_runtime_exceeded(struct rt_rq *rt_rq)
if (sched_rt_runtime(rt_rq) >= sched_rt_period(rt_rq))
return 0;
-#ifdef CONFIG_SMP
- if (rt_rq->rt_time > runtime) {
- int more;
-
- spin_unlock(&rt_rq->rt_runtime_lock);
- more = balance_runtime(rt_rq);
- spin_lock(&rt_rq->rt_runtime_lock);
-
- if (more)
- runtime = sched_rt_runtime(rt_rq);
- }
-#endif
+ balance_runtime(rt_rq);
+ runtime = sched_rt_runtime(rt_rq);
+ if (runtime == RUNTIME_INF)
+ return 0;
if (rt_rq->rt_time > runtime) {
rt_rq->rt_throttled = 1;
@@ -392,12 +504,21 @@ void inc_rt_tasks(struct sched_rt_entity *rt_se, struct rt_rq *rt_rq)
WARN_ON(!rt_prio(rt_se_prio(rt_se)));
rt_rq->rt_nr_running++;
#if defined CONFIG_SMP || defined CONFIG_RT_GROUP_SCHED
- if (rt_se_prio(rt_se) < rt_rq->highest_prio)
+ if (rt_se_prio(rt_se) < rt_rq->highest_prio) {
+ struct rq *rq = rq_of_rt_rq(rt_rq);
+
rt_rq->highest_prio = rt_se_prio(rt_se);
+#ifdef CONFIG_SMP
+ if (rq->online)
+ cpupri_set(&rq->rd->cpupri, rq->cpu,
+ rt_se_prio(rt_se));
+#endif
+ }
#endif
#ifdef CONFIG_SMP
if (rt_se->nr_cpus_allowed > 1) {
struct rq *rq = rq_of_rt_rq(rt_rq);
+
rq->rt.rt_nr_migratory++;
}
@@ -417,6 +538,10 @@ void inc_rt_tasks(struct sched_rt_entity *rt_se, struct rt_rq *rt_rq)
static inline
void dec_rt_tasks(struct sched_rt_entity *rt_se, struct rt_rq *rt_rq)
{
+#ifdef CONFIG_SMP
+ int highest_prio = rt_rq->highest_prio;
+#endif
+
WARN_ON(!rt_prio(rt_se_prio(rt_se)));
WARN_ON(!rt_rq->rt_nr_running);
rt_rq->rt_nr_running--;
@@ -440,6 +565,14 @@ void dec_rt_tasks(struct sched_rt_entity *rt_se, struct rt_rq *rt_rq)
rq->rt.rt_nr_migratory--;
}
+ if (rt_rq->highest_prio != highest_prio) {
+ struct rq *rq = rq_of_rt_rq(rt_rq);
+
+ if (rq->online)
+ cpupri_set(&rq->rd->cpupri, rq->cpu,
+ rt_rq->highest_prio);
+ }
+
update_rt_migration(rq_of_rt_rq(rt_rq));
#endif /* CONFIG_SMP */
#ifdef CONFIG_RT_GROUP_SCHED
@@ -455,6 +588,7 @@ static void __enqueue_rt_entity(struct sched_rt_entity *rt_se)
struct rt_rq *rt_rq = rt_rq_of_se(rt_se);
struct rt_prio_array *array = &rt_rq->active;
struct rt_rq *group_rq = group_rt_rq(rt_se);
+ struct list_head *queue = array->queue + rt_se_prio(rt_se);
/*
* Don't enqueue the group if its throttled, or when empty.
@@ -465,7 +599,11 @@ static void __enqueue_rt_entity(struct sched_rt_entity *rt_se)
if (group_rq && (rt_rq_throttled(group_rq) || !group_rq->rt_nr_running))
return;
- list_add_tail(&rt_se->run_list, array->queue + rt_se_prio(rt_se));
+ if (rt_se->nr_cpus_allowed == 1)
+ list_add(&rt_se->run_list, queue);
+ else
+ list_add_tail(&rt_se->run_list, queue);
+
__set_bit(rt_se_prio(rt_se), array->bitmap);
inc_rt_tasks(rt_se, rt_rq);
@@ -532,6 +670,8 @@ static void enqueue_task_rt(struct rq *rq, struct task_struct *p, int wakeup)
rt_se->timeout = 0;
enqueue_rt_entity(rt_se);
+
+ inc_cpu_load(rq, p->se.load.weight);
}
static void dequeue_task_rt(struct rq *rq, struct task_struct *p, int sleep)
@@ -540,6 +680,8 @@ static void dequeue_task_rt(struct rq *rq, struct task_struct *p, int sleep)
update_curr_rt(rq);
dequeue_rt_entity(rt_se);
+
+ dec_cpu_load(rq, p->se.load.weight);
}
/*
@@ -550,10 +692,12 @@ static
void requeue_rt_entity(struct rt_rq *rt_rq, struct sched_rt_entity *rt_se)
{
struct rt_prio_array *array = &rt_rq->active;
- struct list_head *queue = array->queue + rt_se_prio(rt_se);
- if (on_rt_rq(rt_se))
- list_move_tail(&rt_se->run_list, queue);
+ if (on_rt_rq(rt_se)) {
+ list_del_init(&rt_se->run_list);
+ list_add_tail(&rt_se->run_list,
+ array->queue + rt_se_prio(rt_se));
+ }
}
static void requeue_task_rt(struct rq *rq, struct task_struct *p)
@@ -616,8 +760,37 @@ static int select_task_rq_rt(struct task_struct *p, int sync)
*/
static void check_preempt_curr_rt(struct rq *rq, struct task_struct *p)
{
- if (p->prio < rq->curr->prio)
+ if (p->prio < rq->curr->prio) {
resched_task(rq->curr);
+ return;
+ }
+
+#ifdef CONFIG_SMP
+ /*
+ * If:
+ *
+ * - the newly woken task is of equal priority to the current task
+ * - the newly woken task is non-migratable while current is migratable
+ * - current will be preempted on the next reschedule
+ *
+ * we should check to see if current can readily move to a different
+ * cpu. If so, we will reschedule to allow the push logic to try
+ * to move current somewhere else, making room for our non-migratable
+ * task.
+ */
+ if((p->prio == rq->curr->prio)
+ && p->rt.nr_cpus_allowed == 1
+ && rq->curr->rt.nr_cpus_allowed != 1) {
+ cpumask_t mask;
+
+ if (cpupri_find(&rq->rd->cpupri, rq->curr, &mask))
+ /*
+ * There appears to be other cpus that can accept
+ * current, so lets reschedule to try and push it away
+ */
+ resched_task(rq->curr);
+ }
+#endif
}
static struct sched_rt_entity *pick_next_rt_entity(struct rq *rq,
@@ -720,73 +893,6 @@ static struct task_struct *pick_next_highest_task_rt(struct rq *rq, int cpu)
static DEFINE_PER_CPU(cpumask_t, local_cpu_mask);
-static int find_lowest_cpus(struct task_struct *task, cpumask_t *lowest_mask)
-{
- int lowest_prio = -1;
- int lowest_cpu = -1;
- int count = 0;
- int cpu;
-
- cpus_and(*lowest_mask, task_rq(task)->rd->online, task->cpus_allowed);
-
- /*
- * Scan each rq for the lowest prio.
- */
- for_each_cpu_mask(cpu, *lowest_mask) {
- struct rq *rq = cpu_rq(cpu);
-
- /* We look for lowest RT prio or non-rt CPU */
- if (rq->rt.highest_prio >= MAX_RT_PRIO) {
- /*
- * if we already found a low RT queue
- * and now we found this non-rt queue
- * clear the mask and set our bit.
- * Otherwise just return the queue as is
- * and the count==1 will cause the algorithm
- * to use the first bit found.
- */
- if (lowest_cpu != -1) {
- cpus_clear(*lowest_mask);
- cpu_set(rq->cpu, *lowest_mask);
- }
- return 1;
- }
-
- /* no locking for now */
- if ((rq->rt.highest_prio > task->prio)
- && (rq->rt.highest_prio >= lowest_prio)) {
- if (rq->rt.highest_prio > lowest_prio) {
- /* new low - clear old data */
- lowest_prio = rq->rt.highest_prio;
- lowest_cpu = cpu;
- count = 0;
- }
- count++;
- } else
- cpu_clear(cpu, *lowest_mask);
- }
-
- /*
- * Clear out all the set bits that represent
- * runqueues that were of higher prio than
- * the lowest_prio.
- */
- if (lowest_cpu > 0) {
- /*
- * Perhaps we could add another cpumask op to
- * zero out bits. Like cpu_zero_bits(cpumask, nrbits);
- * Then that could be optimized to use memset and such.
- */
- for_each_cpu_mask(cpu, *lowest_mask) {
- if (cpu >= lowest_cpu)
- break;
- cpu_clear(cpu, *lowest_mask);
- }
- }
-
- return count;
-}
-
static inline int pick_optimal_cpu(int this_cpu, cpumask_t *mask)
{
int first;
@@ -808,17 +914,12 @@ static int find_lowest_rq(struct task_struct *task)
cpumask_t *lowest_mask = &__get_cpu_var(local_cpu_mask);
int this_cpu = smp_processor_id();
int cpu = task_cpu(task);
- int count = find_lowest_cpus(task, lowest_mask);
- if (!count)
- return -1; /* No targets found */
+ if (task->rt.nr_cpus_allowed == 1)
+ return -1; /* No other targets possible */
- /*
- * There is no sense in performing an optimal search if only one
- * target is found.
- */
- if (count == 1)
- return first_cpu(*lowest_mask);
+ if (!cpupri_find(&task_rq(task)->rd->cpupri, task, lowest_mask))
+ return -1; /* No targets found */
/*
* At this point we have built a mask of cpus representing the
@@ -1163,17 +1264,25 @@ static void set_cpus_allowed_rt(struct task_struct *p,
}
/* Assumes rq->lock is held */
-static void join_domain_rt(struct rq *rq)
+static void rq_online_rt(struct rq *rq)
{
if (rq->rt.overloaded)
rt_set_overload(rq);
+
+ __enable_runtime(rq);
+
+ cpupri_set(&rq->rd->cpupri, rq->cpu, rq->rt.highest_prio);
}
/* Assumes rq->lock is held */
-static void leave_domain_rt(struct rq *rq)
+static void rq_offline_rt(struct rq *rq)
{
if (rq->rt.overloaded)
rt_clear_overload(rq);
+
+ __disable_runtime(rq);
+
+ cpupri_set(&rq->rd->cpupri, rq->cpu, CPUPRI_INVALID);
}
/*
@@ -1336,8 +1445,8 @@ static const struct sched_class rt_sched_class = {
.load_balance = load_balance_rt,
.move_one_task = move_one_task_rt,
.set_cpus_allowed = set_cpus_allowed_rt,
- .join_domain = join_domain_rt,
- .leave_domain = leave_domain_rt,
+ .rq_online = rq_online_rt,
+ .rq_offline = rq_offline_rt,
.pre_schedule = pre_schedule_rt,
.post_schedule = post_schedule_rt,
.task_wake_up = task_wake_up_rt,
@@ -1350,3 +1459,17 @@ static const struct sched_class rt_sched_class = {
.prio_changed = prio_changed_rt,
.switched_to = switched_to_rt,
};
+
+#ifdef CONFIG_SCHED_DEBUG
+extern void print_rt_rq(struct seq_file *m, int cpu, struct rt_rq *rt_rq);
+
+static void print_rt_stats(struct seq_file *m, int cpu)
+{
+ struct rt_rq *rt_rq;
+
+ rcu_read_lock();
+ for_each_leaf_rt_rq(rt_rq, cpu_rq(cpu))
+ print_rt_rq(m, cpu, rt_rq);
+ rcu_read_unlock();
+}
+#endif /* CONFIG_SCHED_DEBUG */
diff --git a/kernel/sched_stats.h b/kernel/sched_stats.h
index 80179ef..8385d43 100644
--- a/kernel/sched_stats.h
+++ b/kernel/sched_stats.h
@@ -118,6 +118,13 @@ rq_sched_info_depart(struct rq *rq, unsigned long long delta)
if (rq)
rq->rq_sched_info.cpu_time += delta;
}
+
+static inline void
+rq_sched_info_dequeued(struct rq *rq, unsigned long long delta)
+{
+ if (rq)
+ rq->rq_sched_info.run_delay += delta;
+}
# define schedstat_inc(rq, field) do { (rq)->field++; } while (0)
# define schedstat_add(rq, field, amt) do { (rq)->field += (amt); } while (0)
# define schedstat_set(var, val) do { var = (val); } while (0)
@@ -126,6 +133,9 @@ static inline void
rq_sched_info_arrive(struct rq *rq, unsigned long long delta)
{}
static inline void
+rq_sched_info_dequeued(struct rq *rq, unsigned long long delta)
+{}
+static inline void
rq_sched_info_depart(struct rq *rq, unsigned long long delta)
{}
# define schedstat_inc(rq, field) do { } while (0)
@@ -134,6 +144,11 @@ rq_sched_info_depart(struct rq *rq, unsigned long long delta)
#endif
#if defined(CONFIG_SCHEDSTATS) || defined(CONFIG_TASK_DELAY_ACCT)
+static inline void sched_info_reset_dequeued(struct task_struct *t)
+{
+ t->sched_info.last_queued = 0;
+}
+
/*
* Called when a process is dequeued from the active array and given
* the cpu. We should note that with the exception of interactive
@@ -143,15 +158,22 @@ rq_sched_info_depart(struct rq *rq, unsigned long long delta)
* active queue, thus delaying tasks in the expired queue from running;
* see scheduler_tick()).
*
- * This function is only called from sched_info_arrive(), rather than
- * dequeue_task(). Even though a task may be queued and dequeued multiple
- * times as it is shuffled about, we're really interested in knowing how
- * long it was from the *first* time it was queued to the time that it
- * finally hit a cpu.
+ * Though we are interested in knowing how long it was from the *first* time a
+ * task was queued to the time that it finally hit a cpu, we call this routine
+ * from dequeue_task() to account for possible rq->clock skew across cpus. The
+ * delta taken on each cpu would annul the skew.
*/
static inline void sched_info_dequeued(struct task_struct *t)
{
- t->sched_info.last_queued = 0;
+ unsigned long long now = task_rq(t)->clock, delta = 0;
+
+ if (unlikely(sched_info_on()))
+ if (t->sched_info.last_queued)
+ delta = now - t->sched_info.last_queued;
+ sched_info_reset_dequeued(t);
+ t->sched_info.run_delay += delta;
+
+ rq_sched_info_dequeued(task_rq(t), delta);
}
/*
@@ -165,7 +187,7 @@ static void sched_info_arrive(struct task_struct *t)
if (t->sched_info.last_queued)
delta = now - t->sched_info.last_queued;
- sched_info_dequeued(t);
+ sched_info_reset_dequeued(t);
t->sched_info.run_delay += delta;
t->sched_info.last_arrival = now;
t->sched_info.pcount++;
@@ -242,7 +264,9 @@ sched_info_switch(struct task_struct *prev, struct task_struct *next)
__sched_info_switch(prev, next);
}
#else
-#define sched_info_queued(t) do { } while (0)
-#define sched_info_switch(t, next) do { } while (0)
+#define sched_info_queued(t) do { } while (0)
+#define sched_info_reset_dequeued(t) do { } while (0)
+#define sched_info_dequeued(t) do { } while (0)
+#define sched_info_switch(t, next) do { } while (0)
#endif /* CONFIG_SCHEDSTATS || CONFIG_TASK_DELAY_ACCT */
diff --git a/kernel/sysctl.c b/kernel/sysctl.c
index 2911665..fe8cdc8 100644
--- a/kernel/sysctl.c
+++ b/kernel/sysctl.c
@@ -266,6 +266,14 @@ static struct ctl_table kern_table[] = {
},
{
.ctl_name = CTL_UNNUMBERED,
+ .procname = "sched_shares_ratelimit",
+ .data = &sysctl_sched_shares_ratelimit,
+ .maxlen = sizeof(unsigned int),
+ .mode = 0644,
+ .proc_handler = &proc_dointvec,
+ },
+ {
+ .ctl_name = CTL_UNNUMBERED,
.procname = "sched_child_runs_first",
.data = &sysctl_sched_child_runs_first,
.maxlen = sizeof(unsigned int),
diff --git a/kernel/time/tick-sched.c b/kernel/time/tick-sched.c
index b854a89..d63008b 100644
--- a/kernel/time/tick-sched.c
+++ b/kernel/time/tick-sched.c
@@ -276,6 +276,7 @@ void tick_nohz_stop_sched_tick(void)
ts->tick_stopped = 1;
ts->idle_jiffies = last_jiffies;
rcu_enter_nohz();
+ sched_clock_tick_stop(cpu);
}
/*
@@ -375,6 +376,7 @@ void tick_nohz_restart_sched_tick(void)
select_nohz_load_balancer(0);
now = ktime_get();
tick_do_update_jiffies64(now);
+ sched_clock_tick_start(cpu);
cpu_clear(cpu, nohz_cpu_mask);
/*
--
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