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Date: Mon, 1 May 2017 12:07:20 +0200
From: Ingo Molnar <mingo@...nel.org>
To: Linus Torvalds <torvalds@...ux-foundation.org>
Cc: linux-kernel@...r.kernel.org,
Peter Zijlstra <a.p.zijlstra@...llo.nl>,
Mike Galbraith <efault@....de>,
Thomas Gleixner <tglx@...utronix.de>,
Andrew Morton <akpm@...ux-foundation.org>
Subject: [GIT PULL] scheduler changes for v4.12
Linus,
Please pull the latest sched-core-for-linus git tree from:
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git sched-core-for-linus
# HEAD: 21173d0b4d2a0b9e9e5f3155cf2cfc5781a6f4b1 sched/x86: Update reschedule warning text
The main changes in this cycle were:
- Another round of rq-clock handling debugging, robustization and fixes
- PELT accounting improvements
- CPU hotplug related ->cpus_allowed affinity handling fixes all around the tree
- ... plus misc fixes, cleanups and updates.
Thanks,
Ingo
------------------>
NeilBrown (1):
sched/core: Remove 'task' parameter and rename tsk_restore_flags() to current_restore_flags()
Peter Zijlstra (14):
sched/core: Add WARNING for multiple update_rq_clock() calls
sched/core: Add rq->lock wrappers
sched/core: Add {EN,DE}QUEUE_NOCLOCK flags
sched/core: Add ENQUEUE_NOCLOCK to ENQUEUE_RESTORE
sched/core: Make sched_ttwu_pending() atomic in time
sched/core: Simplify update_rq_clock() in __schedule()
sched/core: Avoid obvious double update_rq_clock()
sched/core: Fix double update_rq_clock) calls in attach_task()/detach_task()
sched/core: Avoid double update_rq_clock() in move_queued_task()
sched/fair: Explicitly generate __update_load_avg() instances
sched/fair: Fix corner case in __accumulate_sum()
sched/fair: Fix comments
sched/fair: Increase PELT accuracy for small tasks
sched/fair: Move the PELT constants into a generated header
Prarit Bhargava (1):
sched/x86: Update reschedule warning text
Srikar Dronamraju (1):
sched/fair: Prefer sibiling only if local group is under-utilized
Steven Rostedt (VMware) (1):
sched/rt: Add comments describing the RT IPI pull method
Thomas Gleixner (13):
ia64/topology: Remove cpus_allowed manipulation
workqueue: Provide work_on_cpu_safe()
ia64/salinfo: Replace racy task affinity logic
ia64/sn/hwperf: Replace racy task affinity logic
powerpc/smp: Replace open coded task affinity logic
sparc/sysfs: Replace racy task affinity logic
ACPI/processor: Fix error handling in __acpi_processor_start()
ACPI/processor: Replace racy task affinity logic
cpufreq/ia64: Replace racy task affinity logic
cpufreq/sh: Replace racy task affinity logic
cpufreq/sparc-us3: Replace racy task affinity logic
cpufreq/sparc-us2e: Replace racy task affinity logic
crypto: N2 - Replace racy task affinity logic
Vincent Guittot (1):
sched/fair: Fix FTQ noise bench regression
Wanpeng Li (1):
sched/core: Fix rq lock pinning warning after call balance callbacks
Yuyang Du (2):
sched/fair: Optimize ___update_sched_avg()
sched/Documentation: Add 'sched-pelt' tool
Documentation/scheduler/sched-pelt.c | 108 +++++++++
arch/ia64/kernel/salinfo.c | 31 +--
arch/ia64/kernel/topology.c | 6 -
arch/ia64/sn/kernel/sn2/sn_hwperf.c | 17 +-
arch/powerpc/kernel/smp.c | 26 +--
arch/sparc/kernel/sysfs.c | 39 +---
arch/x86/kernel/smp.c | 2 +-
drivers/acpi/processor_driver.c | 10 +-
drivers/acpi/processor_throttling.c | 62 +++---
drivers/block/nbd.c | 2 +-
drivers/cpufreq/ia64-acpi-cpufreq.c | 92 ++++----
drivers/cpufreq/sh-cpufreq.c | 45 ++--
drivers/cpufreq/sparc-us2e-cpufreq.c | 45 ++--
drivers/cpufreq/sparc-us3-cpufreq.c | 46 ++--
drivers/crypto/n2_core.c | 31 +--
drivers/scsi/iscsi_tcp.c | 2 +-
fs/nfsd/vfs.c | 2 +-
include/linux/sched.h | 6 +-
include/linux/workqueue.h | 5 +
kernel/sched/core.c | 201 +++++++++--------
kernel/sched/fair.c | 418 +++++++++++++++++++----------------
kernel/sched/features.h | 7 +
kernel/sched/rt.c | 81 +++++++
kernel/sched/sched-pelt.h | 13 ++
kernel/sched/sched.h | 65 +++++-
kernel/softirq.c | 2 +-
kernel/workqueue.c | 23 ++
net/core/dev.c | 2 +-
net/core/sock.c | 2 +-
29 files changed, 847 insertions(+), 544 deletions(-)
create mode 100644 Documentation/scheduler/sched-pelt.c
create mode 100644 kernel/sched/sched-pelt.h
diff --git a/Documentation/scheduler/sched-pelt.c b/Documentation/scheduler/sched-pelt.c
new file mode 100644
index 000000000000..e4219139386a
--- /dev/null
+++ b/Documentation/scheduler/sched-pelt.c
@@ -0,0 +1,108 @@
+/*
+ * The following program is used to generate the constants for
+ * computing sched averages.
+ *
+ * ==============================================================
+ * C program (compile with -lm)
+ * ==============================================================
+ */
+
+#include <math.h>
+#include <stdio.h>
+
+#define HALFLIFE 32
+#define SHIFT 32
+
+double y;
+
+void calc_runnable_avg_yN_inv(void)
+{
+ int i;
+ unsigned int x;
+
+ printf("static const u32 runnable_avg_yN_inv[] = {");
+ for (i = 0; i < HALFLIFE; i++) {
+ x = ((1UL<<32)-1)*pow(y, i);
+
+ if (i % 6 == 0) printf("\n\t");
+ printf("0x%8x, ", x);
+ }
+ printf("\n};\n\n");
+}
+
+int sum = 1024;
+
+void calc_runnable_avg_yN_sum(void)
+{
+ int i;
+
+ printf("static const u32 runnable_avg_yN_sum[] = {\n\t 0,");
+ for (i = 1; i <= HALFLIFE; i++) {
+ if (i == 1)
+ sum *= y;
+ else
+ sum = sum*y + 1024*y;
+
+ if (i % 11 == 0)
+ printf("\n\t");
+
+ printf("%5d,", sum);
+ }
+ printf("\n};\n\n");
+}
+
+int n = -1;
+/* first period */
+long max = 1024;
+
+void calc_converged_max(void)
+{
+ long last = 0, y_inv = ((1UL<<32)-1)*y;
+
+ for (; ; n++) {
+ if (n > -1)
+ max = ((max*y_inv)>>SHIFT) + 1024;
+ /*
+ * This is the same as:
+ * max = max*y + 1024;
+ */
+
+ if (last == max)
+ break;
+
+ last = max;
+ }
+ n--;
+ printf("#define LOAD_AVG_PERIOD %d\n", HALFLIFE);
+ printf("#define LOAD_AVG_MAX %ld\n", max);
+// printf("#define LOAD_AVG_MAX_N %d\n\n", n);
+}
+
+void calc_accumulated_sum_32(void)
+{
+ int i, x = sum;
+
+ printf("static const u32 __accumulated_sum_N32[] = {\n\t 0,");
+ for (i = 1; i <= n/HALFLIFE+1; i++) {
+ if (i > 1)
+ x = x/2 + sum;
+
+ if (i % 6 == 0)
+ printf("\n\t");
+
+ printf("%6d,", x);
+ }
+ printf("\n};\n\n");
+}
+
+void main(void)
+{
+ printf("/* Generated by Documentation/scheduler/sched-pelt; do not modify. */\n\n");
+
+ y = pow(0.5, 1/(double)HALFLIFE);
+
+ calc_runnable_avg_yN_inv();
+// calc_runnable_avg_yN_sum();
+ calc_converged_max();
+// calc_accumulated_sum_32();
+}
diff --git a/arch/ia64/kernel/salinfo.c b/arch/ia64/kernel/salinfo.c
index d194d5c83d32..63dc9cdc95c5 100644
--- a/arch/ia64/kernel/salinfo.c
+++ b/arch/ia64/kernel/salinfo.c
@@ -179,14 +179,14 @@ struct salinfo_platform_oemdata_parms {
const u8 *efi_guid;
u8 **oemdata;
u64 *oemdata_size;
- int ret;
};
-static void
+static long
salinfo_platform_oemdata_cpu(void *context)
{
struct salinfo_platform_oemdata_parms *parms = context;
- parms->ret = salinfo_platform_oemdata(parms->efi_guid, parms->oemdata, parms->oemdata_size);
+
+ return salinfo_platform_oemdata(parms->efi_guid, parms->oemdata, parms->oemdata_size);
}
static void
@@ -380,16 +380,7 @@ salinfo_log_release(struct inode *inode, struct file *file)
return 0;
}
-static void
-call_on_cpu(int cpu, void (*fn)(void *), void *arg)
-{
- cpumask_t save_cpus_allowed = current->cpus_allowed;
- set_cpus_allowed_ptr(current, cpumask_of(cpu));
- (*fn)(arg);
- set_cpus_allowed_ptr(current, &save_cpus_allowed);
-}
-
-static void
+static long
salinfo_log_read_cpu(void *context)
{
struct salinfo_data *data = context;
@@ -399,6 +390,7 @@ salinfo_log_read_cpu(void *context)
/* Clear corrected errors as they are read from SAL */
if (rh->severity == sal_log_severity_corrected)
ia64_sal_clear_state_info(data->type);
+ return 0;
}
static void
@@ -430,7 +422,7 @@ salinfo_log_new_read(int cpu, struct salinfo_data *data)
spin_unlock_irqrestore(&data_saved_lock, flags);
if (!data->saved_num)
- call_on_cpu(cpu, salinfo_log_read_cpu, data);
+ work_on_cpu_safe(cpu, salinfo_log_read_cpu, data);
if (!data->log_size) {
data->state = STATE_NO_DATA;
cpumask_clear_cpu(cpu, &data->cpu_event);
@@ -459,11 +451,13 @@ salinfo_log_read(struct file *file, char __user *buffer, size_t count, loff_t *p
return simple_read_from_buffer(buffer, count, ppos, buf, bufsize);
}
-static void
+static long
salinfo_log_clear_cpu(void *context)
{
struct salinfo_data *data = context;
+
ia64_sal_clear_state_info(data->type);
+ return 0;
}
static int
@@ -486,7 +480,7 @@ salinfo_log_clear(struct salinfo_data *data, int cpu)
rh = (sal_log_record_header_t *)(data->log_buffer);
/* Corrected errors have already been cleared from SAL */
if (rh->severity != sal_log_severity_corrected)
- call_on_cpu(cpu, salinfo_log_clear_cpu, data);
+ work_on_cpu_safe(cpu, salinfo_log_clear_cpu, data);
/* clearing a record may make a new record visible */
salinfo_log_new_read(cpu, data);
if (data->state == STATE_LOG_RECORD) {
@@ -531,9 +525,8 @@ salinfo_log_write(struct file *file, const char __user *buffer, size_t count, lo
.oemdata = &data->oemdata,
.oemdata_size = &data->oemdata_size
};
- call_on_cpu(cpu, salinfo_platform_oemdata_cpu, &parms);
- if (parms.ret)
- count = parms.ret;
+ count = work_on_cpu_safe(cpu, salinfo_platform_oemdata_cpu,
+ &parms);
} else
data->oemdata_size = 0;
} else
diff --git a/arch/ia64/kernel/topology.c b/arch/ia64/kernel/topology.c
index 1a68f012a6dc..d76529cbff20 100644
--- a/arch/ia64/kernel/topology.c
+++ b/arch/ia64/kernel/topology.c
@@ -355,18 +355,12 @@ static int cache_add_dev(unsigned int cpu)
unsigned long i, j;
struct cache_info *this_object;
int retval = 0;
- cpumask_t oldmask;
if (all_cpu_cache_info[cpu].kobj.parent)
return 0;
- oldmask = current->cpus_allowed;
- retval = set_cpus_allowed_ptr(current, cpumask_of(cpu));
- if (unlikely(retval))
- return retval;
retval = cpu_cache_sysfs_init(cpu);
- set_cpus_allowed_ptr(current, &oldmask);
if (unlikely(retval < 0))
return retval;
diff --git a/arch/ia64/sn/kernel/sn2/sn_hwperf.c b/arch/ia64/sn/kernel/sn2/sn_hwperf.c
index 52704f199dd6..55febd65911a 100644
--- a/arch/ia64/sn/kernel/sn2/sn_hwperf.c
+++ b/arch/ia64/sn/kernel/sn2/sn_hwperf.c
@@ -598,12 +598,17 @@ static void sn_hwperf_call_sal(void *info)
op_info->ret = r;
}
+static long sn_hwperf_call_sal_work(void *info)
+{
+ sn_hwperf_call_sal(info);
+ return 0;
+}
+
static int sn_hwperf_op_cpu(struct sn_hwperf_op_info *op_info)
{
u32 cpu;
u32 use_ipi;
int r = 0;
- cpumask_t save_allowed;
cpu = (op_info->a->arg & SN_HWPERF_ARG_CPU_MASK) >> 32;
use_ipi = op_info->a->arg & SN_HWPERF_ARG_USE_IPI_MASK;
@@ -629,13 +634,9 @@ static int sn_hwperf_op_cpu(struct sn_hwperf_op_info *op_info)
/* use an interprocessor interrupt to call SAL */
smp_call_function_single(cpu, sn_hwperf_call_sal,
op_info, 1);
- }
- else {
- /* migrate the task before calling SAL */
- save_allowed = current->cpus_allowed;
- set_cpus_allowed_ptr(current, cpumask_of(cpu));
- sn_hwperf_call_sal(op_info);
- set_cpus_allowed_ptr(current, &save_allowed);
+ } else {
+ /* Call on the target CPU */
+ work_on_cpu_safe(cpu, sn_hwperf_call_sal_work, op_info);
}
}
r = op_info->ret;
diff --git a/arch/powerpc/kernel/smp.c b/arch/powerpc/kernel/smp.c
index 46f89e66a273..d68ed1f004a3 100644
--- a/arch/powerpc/kernel/smp.c
+++ b/arch/powerpc/kernel/smp.c
@@ -787,24 +787,21 @@ static struct sched_domain_topology_level powerpc_topology[] = {
{ NULL, },
};
-void __init smp_cpus_done(unsigned int max_cpus)
+static __init long smp_setup_cpu_workfn(void *data __always_unused)
{
- cpumask_var_t old_mask;
+ smp_ops->setup_cpu(boot_cpuid);
+ return 0;
+}
- /* We want the setup_cpu() here to be called from CPU 0, but our
- * init thread may have been "borrowed" by another CPU in the meantime
- * se we pin us down to CPU 0 for a short while
+void __init smp_cpus_done(unsigned int max_cpus)
+{
+ /*
+ * We want the setup_cpu() here to be called on the boot CPU, but
+ * init might run on any CPU, so make sure it's invoked on the boot
+ * CPU.
*/
- alloc_cpumask_var(&old_mask, GFP_NOWAIT);
- cpumask_copy(old_mask, ¤t->cpus_allowed);
- set_cpus_allowed_ptr(current, cpumask_of(boot_cpuid));
-
if (smp_ops && smp_ops->setup_cpu)
- smp_ops->setup_cpu(boot_cpuid);
-
- set_cpus_allowed_ptr(current, old_mask);
-
- free_cpumask_var(old_mask);
+ work_on_cpu_safe(boot_cpuid, smp_setup_cpu_workfn, NULL);
if (smp_ops && smp_ops->bringup_done)
smp_ops->bringup_done();
@@ -812,7 +809,6 @@ void __init smp_cpus_done(unsigned int max_cpus)
dump_numa_cpu_topology();
set_sched_topology(powerpc_topology);
-
}
#ifdef CONFIG_HOTPLUG_CPU
diff --git a/arch/sparc/kernel/sysfs.c b/arch/sparc/kernel/sysfs.c
index d63fc613e7a9..5fd352b759af 100644
--- a/arch/sparc/kernel/sysfs.c
+++ b/arch/sparc/kernel/sysfs.c
@@ -98,27 +98,7 @@ static struct attribute_group mmu_stat_group = {
.name = "mmu_stats",
};
-/* XXX convert to rusty's on_one_cpu */
-static unsigned long run_on_cpu(unsigned long cpu,
- unsigned long (*func)(unsigned long),
- unsigned long arg)
-{
- cpumask_t old_affinity;
- unsigned long ret;
-
- cpumask_copy(&old_affinity, ¤t->cpus_allowed);
- /* should return -EINVAL to userspace */
- if (set_cpus_allowed_ptr(current, cpumask_of(cpu)))
- return 0;
-
- ret = func(arg);
-
- set_cpus_allowed_ptr(current, &old_affinity);
-
- return ret;
-}
-
-static unsigned long read_mmustat_enable(unsigned long junk)
+static long read_mmustat_enable(void *data __maybe_unused)
{
unsigned long ra = 0;
@@ -127,11 +107,11 @@ static unsigned long read_mmustat_enable(unsigned long junk)
return ra != 0;
}
-static unsigned long write_mmustat_enable(unsigned long val)
+static long write_mmustat_enable(void *data)
{
- unsigned long ra, orig_ra;
+ unsigned long ra, orig_ra, *val = data;
- if (val)
+ if (*val)
ra = __pa(&per_cpu(mmu_stats, smp_processor_id()));
else
ra = 0UL;
@@ -142,7 +122,8 @@ static unsigned long write_mmustat_enable(unsigned long val)
static ssize_t show_mmustat_enable(struct device *s,
struct device_attribute *attr, char *buf)
{
- unsigned long val = run_on_cpu(s->id, read_mmustat_enable, 0);
+ long val = work_on_cpu(s->id, read_mmustat_enable, NULL);
+
return sprintf(buf, "%lx\n", val);
}
@@ -150,13 +131,15 @@ static ssize_t store_mmustat_enable(struct device *s,
struct device_attribute *attr, const char *buf,
size_t count)
{
- unsigned long val, err;
- int ret = sscanf(buf, "%lu", &val);
+ unsigned long val;
+ long err;
+ int ret;
+ ret = sscanf(buf, "%lu", &val);
if (ret != 1)
return -EINVAL;
- err = run_on_cpu(s->id, write_mmustat_enable, val);
+ err = work_on_cpu(s->id, write_mmustat_enable, &val);
if (err)
return -EIO;
diff --git a/arch/x86/kernel/smp.c b/arch/x86/kernel/smp.c
index d3c66a15bbde..3cab8415389a 100644
--- a/arch/x86/kernel/smp.c
+++ b/arch/x86/kernel/smp.c
@@ -124,7 +124,7 @@ static bool smp_no_nmi_ipi = false;
static void native_smp_send_reschedule(int cpu)
{
if (unlikely(cpu_is_offline(cpu))) {
- WARN_ON(1);
+ WARN(1, "sched: Unexpected reschedule of offline CPU#%d!\n", cpu);
return;
}
apic->send_IPI(cpu, RESCHEDULE_VECTOR);
diff --git a/drivers/acpi/processor_driver.c b/drivers/acpi/processor_driver.c
index 9d5f0c7ed3f7..8697a82bd465 100644
--- a/drivers/acpi/processor_driver.c
+++ b/drivers/acpi/processor_driver.c
@@ -251,6 +251,9 @@ static int __acpi_processor_start(struct acpi_device *device)
if (ACPI_SUCCESS(status))
return 0;
+ result = -ENODEV;
+ acpi_pss_perf_exit(pr, device);
+
err_power_exit:
acpi_processor_power_exit(pr);
return result;
@@ -259,11 +262,16 @@ static int __acpi_processor_start(struct acpi_device *device)
static int acpi_processor_start(struct device *dev)
{
struct acpi_device *device = ACPI_COMPANION(dev);
+ int ret;
if (!device)
return -ENODEV;
- return __acpi_processor_start(device);
+ /* Protect against concurrent CPU hotplug operations */
+ get_online_cpus();
+ ret = __acpi_processor_start(device);
+ put_online_cpus();
+ return ret;
}
static int acpi_processor_stop(struct device *dev)
diff --git a/drivers/acpi/processor_throttling.c b/drivers/acpi/processor_throttling.c
index a12f96cc93ff..3de34633f7f9 100644
--- a/drivers/acpi/processor_throttling.c
+++ b/drivers/acpi/processor_throttling.c
@@ -62,8 +62,8 @@ struct acpi_processor_throttling_arg {
#define THROTTLING_POSTCHANGE (2)
static int acpi_processor_get_throttling(struct acpi_processor *pr);
-int acpi_processor_set_throttling(struct acpi_processor *pr,
- int state, bool force);
+static int __acpi_processor_set_throttling(struct acpi_processor *pr,
+ int state, bool force, bool direct);
static int acpi_processor_update_tsd_coord(void)
{
@@ -891,7 +891,8 @@ static int acpi_processor_get_throttling_ptc(struct acpi_processor *pr)
ACPI_DEBUG_PRINT((ACPI_DB_INFO,
"Invalid throttling state, reset\n"));
state = 0;
- ret = acpi_processor_set_throttling(pr, state, true);
+ ret = __acpi_processor_set_throttling(pr, state, true,
+ true);
if (ret)
return ret;
}
@@ -901,36 +902,31 @@ static int acpi_processor_get_throttling_ptc(struct acpi_processor *pr)
return 0;
}
-static int acpi_processor_get_throttling(struct acpi_processor *pr)
+static long __acpi_processor_get_throttling(void *data)
{
- cpumask_var_t saved_mask;
- int ret;
+ struct acpi_processor *pr = data;
+
+ return pr->throttling.acpi_processor_get_throttling(pr);
+}
+static int acpi_processor_get_throttling(struct acpi_processor *pr)
+{
if (!pr)
return -EINVAL;
if (!pr->flags.throttling)
return -ENODEV;
- if (!alloc_cpumask_var(&saved_mask, GFP_KERNEL))
- return -ENOMEM;
-
/*
- * Migrate task to the cpu pointed by pr.
+ * This is either called from the CPU hotplug callback of
+ * processor_driver or via the ACPI probe function. In the latter
+ * case the CPU is not guaranteed to be online. Both call sites are
+ * protected against CPU hotplug.
*/
- cpumask_copy(saved_mask, ¤t->cpus_allowed);
- /* FIXME: use work_on_cpu() */
- if (set_cpus_allowed_ptr(current, cpumask_of(pr->id))) {
- /* Can't migrate to the target pr->id CPU. Exit */
- free_cpumask_var(saved_mask);
+ if (!cpu_online(pr->id))
return -ENODEV;
- }
- ret = pr->throttling.acpi_processor_get_throttling(pr);
- /* restore the previous state */
- set_cpus_allowed_ptr(current, saved_mask);
- free_cpumask_var(saved_mask);
- return ret;
+ return work_on_cpu(pr->id, __acpi_processor_get_throttling, pr);
}
static int acpi_processor_get_fadt_info(struct acpi_processor *pr)
@@ -1080,8 +1076,15 @@ static long acpi_processor_throttling_fn(void *data)
arg->target_state, arg->force);
}
-int acpi_processor_set_throttling(struct acpi_processor *pr,
- int state, bool force)
+static int call_on_cpu(int cpu, long (*fn)(void *), void *arg, bool direct)
+{
+ if (direct)
+ return fn(arg);
+ return work_on_cpu(cpu, fn, arg);
+}
+
+static int __acpi_processor_set_throttling(struct acpi_processor *pr,
+ int state, bool force, bool direct)
{
int ret = 0;
unsigned int i;
@@ -1130,7 +1133,8 @@ int acpi_processor_set_throttling(struct acpi_processor *pr,
arg.pr = pr;
arg.target_state = state;
arg.force = force;
- ret = work_on_cpu(pr->id, acpi_processor_throttling_fn, &arg);
+ ret = call_on_cpu(pr->id, acpi_processor_throttling_fn, &arg,
+ direct);
} else {
/*
* When the T-state coordination is SW_ALL or HW_ALL,
@@ -1163,8 +1167,8 @@ int acpi_processor_set_throttling(struct acpi_processor *pr,
arg.pr = match_pr;
arg.target_state = state;
arg.force = force;
- ret = work_on_cpu(pr->id, acpi_processor_throttling_fn,
- &arg);
+ ret = call_on_cpu(pr->id, acpi_processor_throttling_fn,
+ &arg, direct);
}
}
/*
@@ -1182,6 +1186,12 @@ int acpi_processor_set_throttling(struct acpi_processor *pr,
return ret;
}
+int acpi_processor_set_throttling(struct acpi_processor *pr, int state,
+ bool force)
+{
+ return __acpi_processor_set_throttling(pr, state, force, false);
+}
+
int acpi_processor_get_throttling_info(struct acpi_processor *pr)
{
int result = 0;
diff --git a/drivers/block/nbd.c b/drivers/block/nbd.c
index d8a23561b4cb..3c9052bf2327 100644
--- a/drivers/block/nbd.c
+++ b/drivers/block/nbd.c
@@ -244,7 +244,7 @@ static int sock_xmit(struct nbd_device *nbd, int index, int send,
*sent += result;
} while (msg_data_left(&msg));
- tsk_restore_flags(current, pflags, PF_MEMALLOC);
+ current_restore_flags(pflags, PF_MEMALLOC);
return result;
}
diff --git a/drivers/cpufreq/ia64-acpi-cpufreq.c b/drivers/cpufreq/ia64-acpi-cpufreq.c
index e28a31a40829..a757c0a1e7b5 100644
--- a/drivers/cpufreq/ia64-acpi-cpufreq.c
+++ b/drivers/cpufreq/ia64-acpi-cpufreq.c
@@ -34,6 +34,11 @@ struct cpufreq_acpi_io {
unsigned int resume;
};
+struct cpufreq_acpi_req {
+ unsigned int cpu;
+ unsigned int state;
+};
+
static struct cpufreq_acpi_io *acpi_io_data[NR_CPUS];
static struct cpufreq_driver acpi_cpufreq_driver;
@@ -83,8 +88,7 @@ processor_get_pstate (
static unsigned
extract_clock (
struct cpufreq_acpi_io *data,
- unsigned value,
- unsigned int cpu)
+ unsigned value)
{
unsigned long i;
@@ -98,60 +102,43 @@ extract_clock (
}
-static unsigned int
+static long
processor_get_freq (
- struct cpufreq_acpi_io *data,
- unsigned int cpu)
+ void *arg)
{
- int ret = 0;
- u32 value = 0;
- cpumask_t saved_mask;
- unsigned long clock_freq;
+ struct cpufreq_acpi_req *req = arg;
+ unsigned int cpu = req->cpu;
+ struct cpufreq_acpi_io *data = acpi_io_data[cpu];
+ u32 value;
+ int ret;
pr_debug("processor_get_freq\n");
-
- saved_mask = current->cpus_allowed;
- set_cpus_allowed_ptr(current, cpumask_of(cpu));
if (smp_processor_id() != cpu)
- goto migrate_end;
+ return -EAGAIN;
/* processor_get_pstate gets the instantaneous frequency */
ret = processor_get_pstate(&value);
-
if (ret) {
- set_cpus_allowed_ptr(current, &saved_mask);
pr_warn("get performance failed with error %d\n", ret);
- ret = 0;
- goto migrate_end;
+ return ret;
}
- clock_freq = extract_clock(data, value, cpu);
- ret = (clock_freq*1000);
-
-migrate_end:
- set_cpus_allowed_ptr(current, &saved_mask);
- return ret;
+ return 1000 * extract_clock(data, value);
}
-static int
+static long
processor_set_freq (
- struct cpufreq_acpi_io *data,
- struct cpufreq_policy *policy,
- int state)
+ void *arg)
{
- int ret = 0;
- u32 value = 0;
- cpumask_t saved_mask;
- int retval;
+ struct cpufreq_acpi_req *req = arg;
+ unsigned int cpu = req->cpu;
+ struct cpufreq_acpi_io *data = acpi_io_data[cpu];
+ int ret, state = req->state;
+ u32 value;
pr_debug("processor_set_freq\n");
-
- saved_mask = current->cpus_allowed;
- set_cpus_allowed_ptr(current, cpumask_of(policy->cpu));
- if (smp_processor_id() != policy->cpu) {
- retval = -EAGAIN;
- goto migrate_end;
- }
+ if (smp_processor_id() != cpu)
+ return -EAGAIN;
if (state == data->acpi_data.state) {
if (unlikely(data->resume)) {
@@ -159,8 +146,7 @@ processor_set_freq (
data->resume = 0;
} else {
pr_debug("Already at target state (P%d)\n", state);
- retval = 0;
- goto migrate_end;
+ return 0;
}
}
@@ -171,7 +157,6 @@ processor_set_freq (
* First we write the target state's 'control' value to the
* control_register.
*/
-
value = (u32) data->acpi_data.states[state].control;
pr_debug("Transitioning to state: 0x%08x\n", value);
@@ -179,17 +164,11 @@ processor_set_freq (
ret = processor_set_pstate(value);
if (ret) {
pr_warn("Transition failed with error %d\n", ret);
- retval = -ENODEV;
- goto migrate_end;
+ return -ENODEV;
}
data->acpi_data.state = state;
-
- retval = 0;
-
-migrate_end:
- set_cpus_allowed_ptr(current, &saved_mask);
- return (retval);
+ return 0;
}
@@ -197,11 +176,13 @@ static unsigned int
acpi_cpufreq_get (
unsigned int cpu)
{
- struct cpufreq_acpi_io *data = acpi_io_data[cpu];
+ struct cpufreq_acpi_req req;
+ long ret;
- pr_debug("acpi_cpufreq_get\n");
+ req.cpu = cpu;
+ ret = work_on_cpu(cpu, processor_get_freq, &req);
- return processor_get_freq(data, cpu);
+ return ret > 0 ? (unsigned int) ret : 0;
}
@@ -210,7 +191,12 @@ acpi_cpufreq_target (
struct cpufreq_policy *policy,
unsigned int index)
{
- return processor_set_freq(acpi_io_data[policy->cpu], policy, index);
+ struct cpufreq_acpi_req req;
+
+ req.cpu = policy->cpu;
+ req.state = index;
+
+ return work_on_cpu(req.cpu, processor_set_freq, &req);
}
static int
diff --git a/drivers/cpufreq/sh-cpufreq.c b/drivers/cpufreq/sh-cpufreq.c
index 86628e22b2a3..719c3d9f07fb 100644
--- a/drivers/cpufreq/sh-cpufreq.c
+++ b/drivers/cpufreq/sh-cpufreq.c
@@ -30,54 +30,63 @@
static DEFINE_PER_CPU(struct clk, sh_cpuclk);
+struct cpufreq_target {
+ struct cpufreq_policy *policy;
+ unsigned int freq;
+};
+
static unsigned int sh_cpufreq_get(unsigned int cpu)
{
return (clk_get_rate(&per_cpu(sh_cpuclk, cpu)) + 500) / 1000;
}
-/*
- * Here we notify other drivers of the proposed change and the final change.
- */
-static int sh_cpufreq_target(struct cpufreq_policy *policy,
- unsigned int target_freq,
- unsigned int relation)
+static long __sh_cpufreq_target(void *arg)
{
- unsigned int cpu = policy->cpu;
+ struct cpufreq_target *target = arg;
+ struct cpufreq_policy *policy = target->policy;
+ int cpu = policy->cpu;
struct clk *cpuclk = &per_cpu(sh_cpuclk, cpu);
- cpumask_t cpus_allowed;
struct cpufreq_freqs freqs;
struct device *dev;
long freq;
- cpus_allowed = current->cpus_allowed;
- set_cpus_allowed_ptr(current, cpumask_of(cpu));
-
- BUG_ON(smp_processor_id() != cpu);
+ if (smp_processor_id() != cpu)
+ return -ENODEV;
dev = get_cpu_device(cpu);
/* Convert target_freq from kHz to Hz */
- freq = clk_round_rate(cpuclk, target_freq * 1000);
+ freq = clk_round_rate(cpuclk, target->freq * 1000);
if (freq < (policy->min * 1000) || freq > (policy->max * 1000))
return -EINVAL;
- dev_dbg(dev, "requested frequency %u Hz\n", target_freq * 1000);
+ dev_dbg(dev, "requested frequency %u Hz\n", target->freq * 1000);
freqs.old = sh_cpufreq_get(cpu);
freqs.new = (freq + 500) / 1000;
freqs.flags = 0;
- cpufreq_freq_transition_begin(policy, &freqs);
- set_cpus_allowed_ptr(current, &cpus_allowed);
+ cpufreq_freq_transition_begin(target->policy, &freqs);
clk_set_rate(cpuclk, freq);
- cpufreq_freq_transition_end(policy, &freqs, 0);
+ cpufreq_freq_transition_end(target->policy, &freqs, 0);
dev_dbg(dev, "set frequency %lu Hz\n", freq);
-
return 0;
}
+/*
+ * Here we notify other drivers of the proposed change and the final change.
+ */
+static int sh_cpufreq_target(struct cpufreq_policy *policy,
+ unsigned int target_freq,
+ unsigned int relation)
+{
+ struct cpufreq_target data = { .policy = policy, .freq = target_freq };
+
+ return work_on_cpu(policy->cpu, __sh_cpufreq_target, &data);
+}
+
static int sh_cpufreq_verify(struct cpufreq_policy *policy)
{
struct clk *cpuclk = &per_cpu(sh_cpuclk, policy->cpu);
diff --git a/drivers/cpufreq/sparc-us2e-cpufreq.c b/drivers/cpufreq/sparc-us2e-cpufreq.c
index 35ddb6da93aa..90f33efee5fc 100644
--- a/drivers/cpufreq/sparc-us2e-cpufreq.c
+++ b/drivers/cpufreq/sparc-us2e-cpufreq.c
@@ -118,10 +118,6 @@ static void us2e_transition(unsigned long estar, unsigned long new_bits,
unsigned long clock_tick,
unsigned long old_divisor, unsigned long divisor)
{
- unsigned long flags;
-
- local_irq_save(flags);
-
estar &= ~ESTAR_MODE_DIV_MASK;
/* This is based upon the state transition diagram in the IIe manual. */
@@ -152,8 +148,6 @@ static void us2e_transition(unsigned long estar, unsigned long new_bits,
} else {
BUG();
}
-
- local_irq_restore(flags);
}
static unsigned long index_to_estar_mode(unsigned int index)
@@ -229,48 +223,51 @@ static unsigned long estar_to_divisor(unsigned long estar)
return ret;
}
+static void __us2e_freq_get(void *arg)
+{
+ unsigned long *estar = arg;
+
+ *estar = read_hbreg(HBIRD_ESTAR_MODE_ADDR);
+}
+
static unsigned int us2e_freq_get(unsigned int cpu)
{
- cpumask_t cpus_allowed;
unsigned long clock_tick, estar;
- cpumask_copy(&cpus_allowed, ¤t->cpus_allowed);
- set_cpus_allowed_ptr(current, cpumask_of(cpu));
-
clock_tick = sparc64_get_clock_tick(cpu) / 1000;
- estar = read_hbreg(HBIRD_ESTAR_MODE_ADDR);
-
- set_cpus_allowed_ptr(current, &cpus_allowed);
+ if (smp_call_function_single(cpu, __us2e_freq_get, &estar, 1))
+ return 0;
return clock_tick / estar_to_divisor(estar);
}
-static int us2e_freq_target(struct cpufreq_policy *policy, unsigned int index)
+static void __us2e_freq_target(void *arg)
{
- unsigned int cpu = policy->cpu;
+ unsigned int cpu = smp_processor_id();
+ unsigned int *index = arg;
unsigned long new_bits, new_freq;
unsigned long clock_tick, divisor, old_divisor, estar;
- cpumask_t cpus_allowed;
-
- cpumask_copy(&cpus_allowed, ¤t->cpus_allowed);
- set_cpus_allowed_ptr(current, cpumask_of(cpu));
new_freq = clock_tick = sparc64_get_clock_tick(cpu) / 1000;
- new_bits = index_to_estar_mode(index);
- divisor = index_to_divisor(index);
+ new_bits = index_to_estar_mode(*index);
+ divisor = index_to_divisor(*index);
new_freq /= divisor;
estar = read_hbreg(HBIRD_ESTAR_MODE_ADDR);
old_divisor = estar_to_divisor(estar);
- if (old_divisor != divisor)
+ if (old_divisor != divisor) {
us2e_transition(estar, new_bits, clock_tick * 1000,
old_divisor, divisor);
+ }
+}
- set_cpus_allowed_ptr(current, &cpus_allowed);
+static int us2e_freq_target(struct cpufreq_policy *policy, unsigned int index)
+{
+ unsigned int cpu = policy->cpu;
- return 0;
+ return smp_call_function_single(cpu, __us2e_freq_target, &index, 1);
}
static int __init us2e_freq_cpu_init(struct cpufreq_policy *policy)
diff --git a/drivers/cpufreq/sparc-us3-cpufreq.c b/drivers/cpufreq/sparc-us3-cpufreq.c
index a8d86a449ca1..30645b0118f9 100644
--- a/drivers/cpufreq/sparc-us3-cpufreq.c
+++ b/drivers/cpufreq/sparc-us3-cpufreq.c
@@ -35,22 +35,28 @@ static struct us3_freq_percpu_info *us3_freq_table;
#define SAFARI_CFG_DIV_32 0x0000000080000000UL
#define SAFARI_CFG_DIV_MASK 0x00000000C0000000UL
-static unsigned long read_safari_cfg(void)
+static void read_safari_cfg(void *arg)
{
- unsigned long ret;
+ unsigned long ret, *val = arg;
__asm__ __volatile__("ldxa [%%g0] %1, %0"
: "=&r" (ret)
: "i" (ASI_SAFARI_CONFIG));
- return ret;
+ *val = ret;
}
-static void write_safari_cfg(unsigned long val)
+static void update_safari_cfg(void *arg)
{
+ unsigned long reg, *new_bits = arg;
+
+ read_safari_cfg(®);
+ reg &= ~SAFARI_CFG_DIV_MASK;
+ reg |= *new_bits;
+
__asm__ __volatile__("stxa %0, [%%g0] %1\n\t"
"membar #Sync"
: /* no outputs */
- : "r" (val), "i" (ASI_SAFARI_CONFIG)
+ : "r" (reg), "i" (ASI_SAFARI_CONFIG)
: "memory");
}
@@ -78,29 +84,17 @@ static unsigned long get_current_freq(unsigned int cpu, unsigned long safari_cfg
static unsigned int us3_freq_get(unsigned int cpu)
{
- cpumask_t cpus_allowed;
unsigned long reg;
- unsigned int ret;
-
- cpumask_copy(&cpus_allowed, ¤t->cpus_allowed);
- set_cpus_allowed_ptr(current, cpumask_of(cpu));
-
- reg = read_safari_cfg();
- ret = get_current_freq(cpu, reg);
-
- set_cpus_allowed_ptr(current, &cpus_allowed);
- return ret;
+ if (smp_call_function_single(cpu, read_safari_cfg, ®, 1))
+ return 0;
+ return get_current_freq(cpu, reg);
}
static int us3_freq_target(struct cpufreq_policy *policy, unsigned int index)
{
unsigned int cpu = policy->cpu;
- unsigned long new_bits, new_freq, reg;
- cpumask_t cpus_allowed;
-
- cpumask_copy(&cpus_allowed, ¤t->cpus_allowed);
- set_cpus_allowed_ptr(current, cpumask_of(cpu));
+ unsigned long new_bits, new_freq;
new_freq = sparc64_get_clock_tick(cpu) / 1000;
switch (index) {
@@ -121,15 +115,7 @@ static int us3_freq_target(struct cpufreq_policy *policy, unsigned int index)
BUG();
}
- reg = read_safari_cfg();
-
- reg &= ~SAFARI_CFG_DIV_MASK;
- reg |= new_bits;
- write_safari_cfg(reg);
-
- set_cpus_allowed_ptr(current, &cpus_allowed);
-
- return 0;
+ return smp_call_function_single(cpu, update_safari_cfg, &new_bits, 1);
}
static int __init us3_freq_cpu_init(struct cpufreq_policy *policy)
diff --git a/drivers/crypto/n2_core.c b/drivers/crypto/n2_core.c
index c5aac25a5738..4ecb77aa60e1 100644
--- a/drivers/crypto/n2_core.c
+++ b/drivers/crypto/n2_core.c
@@ -65,6 +65,11 @@ struct spu_queue {
struct list_head list;
};
+struct spu_qreg {
+ struct spu_queue *queue;
+ unsigned long type;
+};
+
static struct spu_queue **cpu_to_cwq;
static struct spu_queue **cpu_to_mau;
@@ -1631,31 +1636,27 @@ static void queue_cache_destroy(void)
kmem_cache_destroy(queue_cache[HV_NCS_QTYPE_CWQ - 1]);
}
-static int spu_queue_register(struct spu_queue *p, unsigned long q_type)
+static long spu_queue_register_workfn(void *arg)
{
- cpumask_var_t old_allowed;
+ struct spu_qreg *qr = arg;
+ struct spu_queue *p = qr->queue;
+ unsigned long q_type = qr->type;
unsigned long hv_ret;
- if (cpumask_empty(&p->sharing))
- return -EINVAL;
-
- if (!alloc_cpumask_var(&old_allowed, GFP_KERNEL))
- return -ENOMEM;
-
- cpumask_copy(old_allowed, ¤t->cpus_allowed);
-
- set_cpus_allowed_ptr(current, &p->sharing);
-
hv_ret = sun4v_ncs_qconf(q_type, __pa(p->q),
CWQ_NUM_ENTRIES, &p->qhandle);
if (!hv_ret)
sun4v_ncs_sethead_marker(p->qhandle, 0);
- set_cpus_allowed_ptr(current, old_allowed);
+ return hv_ret ? -EINVAL : 0;
+}
- free_cpumask_var(old_allowed);
+static int spu_queue_register(struct spu_queue *p, unsigned long q_type)
+{
+ int cpu = cpumask_any_and(&p->sharing, cpu_online_mask);
+ struct spu_qreg qr = { .queue = p, .type = q_type };
- return (hv_ret ? -EINVAL : 0);
+ return work_on_cpu_safe(cpu, spu_queue_register_workfn, &qr);
}
static int spu_queue_setup(struct spu_queue *p)
diff --git a/drivers/scsi/iscsi_tcp.c b/drivers/scsi/iscsi_tcp.c
index 4228aba1f654..bbea8eac9abb 100644
--- a/drivers/scsi/iscsi_tcp.c
+++ b/drivers/scsi/iscsi_tcp.c
@@ -387,7 +387,7 @@ static int iscsi_sw_tcp_pdu_xmit(struct iscsi_task *task)
rc = 0;
}
- tsk_restore_flags(current, pflags, PF_MEMALLOC);
+ current_restore_flags(pflags, PF_MEMALLOC);
return rc;
}
diff --git a/fs/nfsd/vfs.c b/fs/nfsd/vfs.c
index 19d50f600e8d..9aaf6ca77569 100644
--- a/fs/nfsd/vfs.c
+++ b/fs/nfsd/vfs.c
@@ -1004,7 +1004,7 @@ nfsd_vfs_write(struct svc_rqst *rqstp, struct svc_fh *fhp, struct file *file,
else
err = nfserrno(host_err);
if (test_bit(RQ_LOCAL, &rqstp->rq_flags))
- tsk_restore_flags(current, pflags, PF_LESS_THROTTLE);
+ current_restore_flags(pflags, PF_LESS_THROTTLE);
return err;
}
diff --git a/include/linux/sched.h b/include/linux/sched.h
index d67eee84fd43..0978fb74e45a 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -1286,10 +1286,10 @@ TASK_PFA_TEST(LMK_WAITING, lmk_waiting)
TASK_PFA_SET(LMK_WAITING, lmk_waiting)
static inline void
-tsk_restore_flags(struct task_struct *task, unsigned long orig_flags, unsigned long flags)
+current_restore_flags(unsigned long orig_flags, unsigned long flags)
{
- task->flags &= ~flags;
- task->flags |= orig_flags & flags;
+ current->flags &= ~flags;
+ current->flags |= orig_flags & flags;
}
extern int cpuset_cpumask_can_shrink(const struct cpumask *cur, const struct cpumask *trial);
diff --git a/include/linux/workqueue.h b/include/linux/workqueue.h
index bde063cefd04..c102ef65cb64 100644
--- a/include/linux/workqueue.h
+++ b/include/linux/workqueue.h
@@ -608,8 +608,13 @@ static inline long work_on_cpu(int cpu, long (*fn)(void *), void *arg)
{
return fn(arg);
}
+static inline long work_on_cpu_safe(int cpu, long (*fn)(void *), void *arg)
+{
+ return fn(arg);
+}
#else
long work_on_cpu(int cpu, long (*fn)(void *), void *arg);
+long work_on_cpu_safe(int cpu, long (*fn)(void *), void *arg);
#endif /* CONFIG_SMP */
#ifdef CONFIG_FREEZER
diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index 3b31fc05a0f1..ab9f6ac099a7 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -86,21 +86,6 @@ int sysctl_sched_rt_runtime = 950000;
cpumask_var_t cpu_isolated_map;
/*
- * this_rq_lock - lock this runqueue and disable interrupts.
- */
-static struct rq *this_rq_lock(void)
- __acquires(rq->lock)
-{
- struct rq *rq;
-
- local_irq_disable();
- rq = this_rq();
- raw_spin_lock(&rq->lock);
-
- return rq;
-}
-
-/*
* __task_rq_lock - lock the rq @p resides on.
*/
struct rq *__task_rq_lock(struct task_struct *p, struct rq_flags *rf)
@@ -233,8 +218,11 @@ void update_rq_clock(struct rq *rq)
return;
#ifdef CONFIG_SCHED_DEBUG
+ if (sched_feat(WARN_DOUBLE_CLOCK))
+ SCHED_WARN_ON(rq->clock_update_flags & RQCF_UPDATED);
rq->clock_update_flags |= RQCF_UPDATED;
#endif
+
delta = sched_clock_cpu(cpu_of(rq)) - rq->clock;
if (delta < 0)
return;
@@ -261,13 +249,14 @@ static void hrtick_clear(struct rq *rq)
static enum hrtimer_restart hrtick(struct hrtimer *timer)
{
struct rq *rq = container_of(timer, struct rq, hrtick_timer);
+ struct rq_flags rf;
WARN_ON_ONCE(cpu_of(rq) != smp_processor_id());
- raw_spin_lock(&rq->lock);
+ rq_lock(rq, &rf);
update_rq_clock(rq);
rq->curr->sched_class->task_tick(rq, rq->curr, 1);
- raw_spin_unlock(&rq->lock);
+ rq_unlock(rq, &rf);
return HRTIMER_NORESTART;
}
@@ -287,11 +276,12 @@ static void __hrtick_restart(struct rq *rq)
static void __hrtick_start(void *arg)
{
struct rq *rq = arg;
+ struct rq_flags rf;
- raw_spin_lock(&rq->lock);
+ rq_lock(rq, &rf);
__hrtick_restart(rq);
rq->hrtick_csd_pending = 0;
- raw_spin_unlock(&rq->lock);
+ rq_unlock(rq, &rf);
}
/*
@@ -762,17 +752,23 @@ static void set_load_weight(struct task_struct *p)
static inline void enqueue_task(struct rq *rq, struct task_struct *p, int flags)
{
- update_rq_clock(rq);
+ if (!(flags & ENQUEUE_NOCLOCK))
+ update_rq_clock(rq);
+
if (!(flags & ENQUEUE_RESTORE))
sched_info_queued(rq, p);
+
p->sched_class->enqueue_task(rq, p, flags);
}
static inline void dequeue_task(struct rq *rq, struct task_struct *p, int flags)
{
- update_rq_clock(rq);
+ if (!(flags & DEQUEUE_NOCLOCK))
+ update_rq_clock(rq);
+
if (!(flags & DEQUEUE_SAVE))
sched_info_dequeued(rq, p);
+
p->sched_class->dequeue_task(rq, p, flags);
}
@@ -946,18 +942,19 @@ void check_preempt_curr(struct rq *rq, struct task_struct *p, int flags)
*
* Returns (locked) new rq. Old rq's lock is released.
*/
-static struct rq *move_queued_task(struct rq *rq, struct task_struct *p, int new_cpu)
+static struct rq *move_queued_task(struct rq *rq, struct rq_flags *rf,
+ struct task_struct *p, int new_cpu)
{
lockdep_assert_held(&rq->lock);
p->on_rq = TASK_ON_RQ_MIGRATING;
- dequeue_task(rq, p, 0);
+ dequeue_task(rq, p, DEQUEUE_NOCLOCK);
set_task_cpu(p, new_cpu);
- raw_spin_unlock(&rq->lock);
+ rq_unlock(rq, rf);
rq = cpu_rq(new_cpu);
- raw_spin_lock(&rq->lock);
+ rq_lock(rq, rf);
BUG_ON(task_cpu(p) != new_cpu);
enqueue_task(rq, p, 0);
p->on_rq = TASK_ON_RQ_QUEUED;
@@ -980,7 +977,8 @@ struct migration_arg {
* So we race with normal scheduler movements, but that's OK, as long
* as the task is no longer on this CPU.
*/
-static struct rq *__migrate_task(struct rq *rq, struct task_struct *p, int dest_cpu)
+static struct rq *__migrate_task(struct rq *rq, struct rq_flags *rf,
+ struct task_struct *p, int dest_cpu)
{
if (unlikely(!cpu_active(dest_cpu)))
return rq;
@@ -989,7 +987,8 @@ static struct rq *__migrate_task(struct rq *rq, struct task_struct *p, int dest_
if (!cpumask_test_cpu(dest_cpu, &p->cpus_allowed))
return rq;
- rq = move_queued_task(rq, p, dest_cpu);
+ update_rq_clock(rq);
+ rq = move_queued_task(rq, rf, p, dest_cpu);
return rq;
}
@@ -1004,6 +1003,7 @@ static int migration_cpu_stop(void *data)
struct migration_arg *arg = data;
struct task_struct *p = arg->task;
struct rq *rq = this_rq();
+ struct rq_flags rf;
/*
* The original target CPU might have gone down and we might
@@ -1018,7 +1018,7 @@ static int migration_cpu_stop(void *data)
sched_ttwu_pending();
raw_spin_lock(&p->pi_lock);
- raw_spin_lock(&rq->lock);
+ rq_lock(rq, &rf);
/*
* If task_rq(p) != rq, it cannot be migrated here, because we're
* holding rq->lock, if p->on_rq == 0 it cannot get enqueued because
@@ -1026,11 +1026,11 @@ static int migration_cpu_stop(void *data)
*/
if (task_rq(p) == rq) {
if (task_on_rq_queued(p))
- rq = __migrate_task(rq, p, arg->dest_cpu);
+ rq = __migrate_task(rq, &rf, p, arg->dest_cpu);
else
p->wake_cpu = arg->dest_cpu;
}
- raw_spin_unlock(&rq->lock);
+ rq_unlock(rq, &rf);
raw_spin_unlock(&p->pi_lock);
local_irq_enable();
@@ -1063,7 +1063,7 @@ void do_set_cpus_allowed(struct task_struct *p, const struct cpumask *new_mask)
* holding rq->lock.
*/
lockdep_assert_held(&rq->lock);
- dequeue_task(rq, p, DEQUEUE_SAVE);
+ dequeue_task(rq, p, DEQUEUE_SAVE | DEQUEUE_NOCLOCK);
}
if (running)
put_prev_task(rq, p);
@@ -1071,7 +1071,7 @@ void do_set_cpus_allowed(struct task_struct *p, const struct cpumask *new_mask)
p->sched_class->set_cpus_allowed(p, new_mask);
if (queued)
- enqueue_task(rq, p, ENQUEUE_RESTORE);
+ enqueue_task(rq, p, ENQUEUE_RESTORE | ENQUEUE_NOCLOCK);
if (running)
set_curr_task(rq, p);
}
@@ -1150,9 +1150,7 @@ static int __set_cpus_allowed_ptr(struct task_struct *p,
* OK, since we're going to drop the lock immediately
* afterwards anyway.
*/
- rq_unpin_lock(rq, &rf);
- rq = move_queued_task(rq, p, dest_cpu);
- rq_repin_lock(rq, &rf);
+ rq = move_queued_task(rq, &rf, p, dest_cpu);
}
out:
task_rq_unlock(rq, p, &rf);
@@ -1217,16 +1215,24 @@ static void __migrate_swap_task(struct task_struct *p, int cpu)
{
if (task_on_rq_queued(p)) {
struct rq *src_rq, *dst_rq;
+ struct rq_flags srf, drf;
src_rq = task_rq(p);
dst_rq = cpu_rq(cpu);
+ rq_pin_lock(src_rq, &srf);
+ rq_pin_lock(dst_rq, &drf);
+
p->on_rq = TASK_ON_RQ_MIGRATING;
deactivate_task(src_rq, p, 0);
set_task_cpu(p, cpu);
activate_task(dst_rq, p, 0);
p->on_rq = TASK_ON_RQ_QUEUED;
check_preempt_curr(dst_rq, p, 0);
+
+ rq_unpin_lock(dst_rq, &drf);
+ rq_unpin_lock(src_rq, &srf);
+
} else {
/*
* Task isn't running anymore; make it appear like we migrated
@@ -1680,7 +1686,7 @@ static void
ttwu_do_activate(struct rq *rq, struct task_struct *p, int wake_flags,
struct rq_flags *rf)
{
- int en_flags = ENQUEUE_WAKEUP;
+ int en_flags = ENQUEUE_WAKEUP | ENQUEUE_NOCLOCK;
lockdep_assert_held(&rq->lock);
@@ -1726,14 +1732,13 @@ void sched_ttwu_pending(void)
struct rq *rq = this_rq();
struct llist_node *llist = llist_del_all(&rq->wake_list);
struct task_struct *p;
- unsigned long flags;
struct rq_flags rf;
if (!llist)
return;
- raw_spin_lock_irqsave(&rq->lock, flags);
- rq_pin_lock(rq, &rf);
+ rq_lock_irqsave(rq, &rf);
+ update_rq_clock(rq);
while (llist) {
int wake_flags = 0;
@@ -1747,8 +1752,7 @@ void sched_ttwu_pending(void)
ttwu_do_activate(rq, p, wake_flags, &rf);
}
- rq_unpin_lock(rq, &rf);
- raw_spin_unlock_irqrestore(&rq->lock, flags);
+ rq_unlock_irqrestore(rq, &rf);
}
void scheduler_ipi(void)
@@ -1806,7 +1810,7 @@ static void ttwu_queue_remote(struct task_struct *p, int cpu, int wake_flags)
void wake_up_if_idle(int cpu)
{
struct rq *rq = cpu_rq(cpu);
- unsigned long flags;
+ struct rq_flags rf;
rcu_read_lock();
@@ -1816,11 +1820,11 @@ void wake_up_if_idle(int cpu)
if (set_nr_if_polling(rq->idle)) {
trace_sched_wake_idle_without_ipi(cpu);
} else {
- raw_spin_lock_irqsave(&rq->lock, flags);
+ rq_lock_irqsave(rq, &rf);
if (is_idle_task(rq->curr))
smp_send_reschedule(cpu);
/* Else CPU is not idle, do nothing here: */
- raw_spin_unlock_irqrestore(&rq->lock, flags);
+ rq_unlock_irqrestore(rq, &rf);
}
out:
@@ -1846,11 +1850,10 @@ static void ttwu_queue(struct task_struct *p, int cpu, int wake_flags)
}
#endif
- raw_spin_lock(&rq->lock);
- rq_pin_lock(rq, &rf);
+ rq_lock(rq, &rf);
+ update_rq_clock(rq);
ttwu_do_activate(rq, p, wake_flags, &rf);
- rq_unpin_lock(rq, &rf);
- raw_spin_unlock(&rq->lock);
+ rq_unlock(rq, &rf);
}
/*
@@ -2097,11 +2100,9 @@ static void try_to_wake_up_local(struct task_struct *p, struct rq_flags *rf)
* disabled avoiding further scheduler activity on it and we've
* not yet picked a replacement task.
*/
- rq_unpin_lock(rq, rf);
- raw_spin_unlock(&rq->lock);
+ rq_unlock(rq, rf);
raw_spin_lock(&p->pi_lock);
- raw_spin_lock(&rq->lock);
- rq_repin_lock(rq, rf);
+ rq_relock(rq, rf);
}
if (!(p->state & TASK_NORMAL))
@@ -2114,7 +2115,7 @@ static void try_to_wake_up_local(struct task_struct *p, struct rq_flags *rf)
delayacct_blkio_end();
atomic_dec(&rq->nr_iowait);
}
- ttwu_activate(rq, p, ENQUEUE_WAKEUP);
+ ttwu_activate(rq, p, ENQUEUE_WAKEUP | ENQUEUE_NOCLOCK);
}
ttwu_do_wakeup(rq, p, 0, rf);
@@ -2555,7 +2556,7 @@ void wake_up_new_task(struct task_struct *p)
update_rq_clock(rq);
post_init_entity_util_avg(&p->se);
- activate_task(rq, p, 0);
+ activate_task(rq, p, ENQUEUE_NOCLOCK);
p->on_rq = TASK_ON_RQ_QUEUED;
trace_sched_wakeup_new(p);
check_preempt_curr(rq, p, WF_FORK);
@@ -3093,15 +3094,18 @@ void scheduler_tick(void)
int cpu = smp_processor_id();
struct rq *rq = cpu_rq(cpu);
struct task_struct *curr = rq->curr;
+ struct rq_flags rf;
sched_clock_tick();
- raw_spin_lock(&rq->lock);
+ rq_lock(rq, &rf);
+
update_rq_clock(rq);
curr->sched_class->task_tick(rq, curr, 0);
cpu_load_update_active(rq);
calc_global_load_tick(rq);
- raw_spin_unlock(&rq->lock);
+
+ rq_unlock(rq, &rf);
perf_event_task_tick();
@@ -3386,18 +3390,18 @@ static void __sched notrace __schedule(bool preempt)
* done by the caller to avoid the race with signal_wake_up().
*/
smp_mb__before_spinlock();
- raw_spin_lock(&rq->lock);
- rq_pin_lock(rq, &rf);
+ rq_lock(rq, &rf);
/* Promote REQ to ACT */
rq->clock_update_flags <<= 1;
+ update_rq_clock(rq);
switch_count = &prev->nivcsw;
if (!preempt && prev->state) {
if (unlikely(signal_pending_state(prev->state, prev))) {
prev->state = TASK_RUNNING;
} else {
- deactivate_task(rq, prev, DEQUEUE_SLEEP);
+ deactivate_task(rq, prev, DEQUEUE_SLEEP | DEQUEUE_NOCLOCK);
prev->on_rq = 0;
if (prev->in_iowait) {
@@ -3421,9 +3425,6 @@ static void __sched notrace __schedule(bool preempt)
switch_count = &prev->nvcsw;
}
- if (task_on_rq_queued(prev))
- update_rq_clock(rq);
-
next = pick_next_task(rq, prev, &rf);
clear_tsk_need_resched(prev);
clear_preempt_need_resched();
@@ -3439,8 +3440,7 @@ static void __sched notrace __schedule(bool preempt)
rq = context_switch(rq, prev, next, &rf);
} else {
rq->clock_update_flags &= ~(RQCF_ACT_SKIP|RQCF_REQ_SKIP);
- rq_unpin_lock(rq, &rf);
- raw_spin_unlock_irq(&rq->lock);
+ rq_unlock_irq(rq, &rf);
}
balance_callback(rq);
@@ -3684,7 +3684,8 @@ EXPORT_SYMBOL(default_wake_function);
*/
void rt_mutex_setprio(struct task_struct *p, int prio)
{
- int oldprio, queued, running, queue_flag = DEQUEUE_SAVE | DEQUEUE_MOVE;
+ int oldprio, queued, running, queue_flag =
+ DEQUEUE_SAVE | DEQUEUE_MOVE | DEQUEUE_NOCLOCK;
const struct sched_class *prev_class;
struct rq_flags rf;
struct rq *rq;
@@ -3805,7 +3806,7 @@ void set_user_nice(struct task_struct *p, long nice)
queued = task_on_rq_queued(p);
running = task_current(rq, p);
if (queued)
- dequeue_task(rq, p, DEQUEUE_SAVE);
+ dequeue_task(rq, p, DEQUEUE_SAVE | DEQUEUE_NOCLOCK);
if (running)
put_prev_task(rq, p);
@@ -3816,7 +3817,7 @@ void set_user_nice(struct task_struct *p, long nice)
delta = p->prio - old_prio;
if (queued) {
- enqueue_task(rq, p, ENQUEUE_RESTORE);
+ enqueue_task(rq, p, ENQUEUE_RESTORE | ENQUEUE_NOCLOCK);
/*
* If the task increased its priority or is running and
* lowered its priority, then reschedule its CPU:
@@ -4126,7 +4127,7 @@ static int __sched_setscheduler(struct task_struct *p,
const struct sched_class *prev_class;
struct rq_flags rf;
int reset_on_fork;
- int queue_flags = DEQUEUE_SAVE | DEQUEUE_MOVE;
+ int queue_flags = DEQUEUE_SAVE | DEQUEUE_MOVE | DEQUEUE_NOCLOCK;
struct rq *rq;
/* May grab non-irq protected spin_locks: */
@@ -4923,7 +4924,12 @@ SYSCALL_DEFINE3(sched_getaffinity, pid_t, pid, unsigned int, len,
*/
SYSCALL_DEFINE0(sched_yield)
{
- struct rq *rq = this_rq_lock();
+ struct rq_flags rf;
+ struct rq *rq;
+
+ local_irq_disable();
+ rq = this_rq();
+ rq_lock(rq, &rf);
schedstat_inc(rq->yld_count);
current->sched_class->yield_task(rq);
@@ -4932,9 +4938,8 @@ SYSCALL_DEFINE0(sched_yield)
* Since we are going to call schedule() anyway, there's
* no need to preempt or enable interrupts:
*/
- __release(rq->lock);
- spin_release(&rq->lock.dep_map, 1, _THIS_IP_);
- do_raw_spin_unlock(&rq->lock);
+ preempt_disable();
+ rq_unlock(rq, &rf);
sched_preempt_enable_no_resched();
schedule();
@@ -5514,7 +5519,7 @@ void sched_setnuma(struct task_struct *p, int nid)
p->numa_preferred_nid = nid;
if (queued)
- enqueue_task(rq, p, ENQUEUE_RESTORE);
+ enqueue_task(rq, p, ENQUEUE_RESTORE | ENQUEUE_NOCLOCK);
if (running)
set_curr_task(rq, p);
task_rq_unlock(rq, p, &rf);
@@ -5579,11 +5584,11 @@ static struct task_struct fake_task = {
* there's no concurrency possible, we hold the required locks anyway
* because of lock validation efforts.
*/
-static void migrate_tasks(struct rq *dead_rq)
+static void migrate_tasks(struct rq *dead_rq, struct rq_flags *rf)
{
struct rq *rq = dead_rq;
struct task_struct *next, *stop = rq->stop;
- struct rq_flags rf;
+ struct rq_flags orf = *rf;
int dest_cpu;
/*
@@ -5602,9 +5607,7 @@ static void migrate_tasks(struct rq *dead_rq)
* class method both need to have an up-to-date
* value of rq->clock[_task]
*/
- rq_pin_lock(rq, &rf);
update_rq_clock(rq);
- rq_unpin_lock(rq, &rf);
for (;;) {
/*
@@ -5617,8 +5620,7 @@ static void migrate_tasks(struct rq *dead_rq)
/*
* pick_next_task() assumes pinned rq->lock:
*/
- rq_repin_lock(rq, &rf);
- next = pick_next_task(rq, &fake_task, &rf);
+ next = pick_next_task(rq, &fake_task, rf);
BUG_ON(!next);
next->sched_class->put_prev_task(rq, next);
@@ -5631,10 +5633,9 @@ static void migrate_tasks(struct rq *dead_rq)
* because !cpu_active at this point, which means load-balance
* will not interfere. Also, stop-machine.
*/
- rq_unpin_lock(rq, &rf);
- raw_spin_unlock(&rq->lock);
+ rq_unlock(rq, rf);
raw_spin_lock(&next->pi_lock);
- raw_spin_lock(&rq->lock);
+ rq_relock(rq, rf);
/*
* Since we're inside stop-machine, _nothing_ should have
@@ -5648,12 +5649,12 @@ static void migrate_tasks(struct rq *dead_rq)
/* Find suitable destination for @next, with force if needed. */
dest_cpu = select_fallback_rq(dead_rq->cpu, next);
-
- rq = __migrate_task(rq, next, dest_cpu);
+ rq = __migrate_task(rq, rf, next, dest_cpu);
if (rq != dead_rq) {
- raw_spin_unlock(&rq->lock);
+ rq_unlock(rq, rf);
rq = dead_rq;
- raw_spin_lock(&rq->lock);
+ *rf = orf;
+ rq_relock(rq, rf);
}
raw_spin_unlock(&next->pi_lock);
}
@@ -5766,7 +5767,7 @@ static int cpuset_cpu_inactive(unsigned int cpu)
int sched_cpu_activate(unsigned int cpu)
{
struct rq *rq = cpu_rq(cpu);
- unsigned long flags;
+ struct rq_flags rf;
set_cpu_active(cpu, true);
@@ -5784,12 +5785,12 @@ int sched_cpu_activate(unsigned int cpu)
* 2) At runtime, if cpuset_cpu_active() fails to rebuild the
* domains.
*/
- raw_spin_lock_irqsave(&rq->lock, flags);
+ rq_lock_irqsave(rq, &rf);
if (rq->rd) {
BUG_ON(!cpumask_test_cpu(cpu, rq->rd->span));
set_rq_online(rq);
}
- raw_spin_unlock_irqrestore(&rq->lock, flags);
+ rq_unlock_irqrestore(rq, &rf);
update_max_interval();
@@ -5847,18 +5848,20 @@ int sched_cpu_starting(unsigned int cpu)
int sched_cpu_dying(unsigned int cpu)
{
struct rq *rq = cpu_rq(cpu);
- unsigned long flags;
+ struct rq_flags rf;
/* Handle pending wakeups and then migrate everything off */
sched_ttwu_pending();
- raw_spin_lock_irqsave(&rq->lock, flags);
+
+ rq_lock_irqsave(rq, &rf);
if (rq->rd) {
BUG_ON(!cpumask_test_cpu(cpu, rq->rd->span));
set_rq_offline(rq);
}
- migrate_tasks(rq);
+ migrate_tasks(rq, &rf);
BUG_ON(rq->nr_running != 1);
- raw_spin_unlock_irqrestore(&rq->lock, flags);
+ rq_unlock_irqrestore(rq, &rf);
+
calc_load_migrate(rq);
update_max_interval();
nohz_balance_exit_idle(cpu);
@@ -6412,7 +6415,8 @@ static void sched_change_group(struct task_struct *tsk, int type)
*/
void sched_move_task(struct task_struct *tsk)
{
- int queued, running;
+ int queued, running, queue_flags =
+ DEQUEUE_SAVE | DEQUEUE_MOVE | DEQUEUE_NOCLOCK;
struct rq_flags rf;
struct rq *rq;
@@ -6423,14 +6427,14 @@ void sched_move_task(struct task_struct *tsk)
queued = task_on_rq_queued(tsk);
if (queued)
- dequeue_task(rq, tsk, DEQUEUE_SAVE | DEQUEUE_MOVE);
+ dequeue_task(rq, tsk, queue_flags);
if (running)
put_prev_task(rq, tsk);
sched_change_group(tsk, TASK_MOVE_GROUP);
if (queued)
- enqueue_task(rq, tsk, ENQUEUE_RESTORE | ENQUEUE_MOVE);
+ enqueue_task(rq, tsk, queue_flags);
if (running)
set_curr_task(rq, tsk);
@@ -7008,14 +7012,15 @@ static int tg_set_cfs_bandwidth(struct task_group *tg, u64 period, u64 quota)
for_each_online_cpu(i) {
struct cfs_rq *cfs_rq = tg->cfs_rq[i];
struct rq *rq = cfs_rq->rq;
+ struct rq_flags rf;
- raw_spin_lock_irq(&rq->lock);
+ rq_lock_irq(rq, &rf);
cfs_rq->runtime_enabled = runtime_enabled;
cfs_rq->runtime_remaining = 0;
if (cfs_rq->throttled)
unthrottle_cfs_rq(cfs_rq);
- raw_spin_unlock_irq(&rq->lock);
+ rq_unlock_irq(rq, &rf);
}
if (runtime_was_enabled && !runtime_enabled)
cfs_bandwidth_usage_dec();
diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index dea138964b91..a903276fcb62 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -717,18 +717,12 @@ static u64 sched_vslice(struct cfs_rq *cfs_rq, struct sched_entity *se)
}
#ifdef CONFIG_SMP
+
+#include "sched-pelt.h"
+
static int select_idle_sibling(struct task_struct *p, int prev_cpu, int cpu);
static unsigned long task_h_load(struct task_struct *p);
-/*
- * We choose a half-life close to 1 scheduling period.
- * Note: The tables runnable_avg_yN_inv and runnable_avg_yN_sum are
- * dependent on this value.
- */
-#define LOAD_AVG_PERIOD 32
-#define LOAD_AVG_MAX 47742 /* maximum possible load avg */
-#define LOAD_AVG_MAX_N 345 /* number of full periods to produce LOAD_AVG_MAX */
-
/* Give new sched_entity start runnable values to heavy its load in infant time */
void init_entity_runnable_average(struct sched_entity *se)
{
@@ -2733,47 +2727,15 @@ static inline void update_cfs_shares(struct sched_entity *se)
#endif /* CONFIG_FAIR_GROUP_SCHED */
#ifdef CONFIG_SMP
-/* Precomputed fixed inverse multiplies for multiplication by y^n */
-static const u32 runnable_avg_yN_inv[] = {
- 0xffffffff, 0xfa83b2da, 0xf5257d14, 0xefe4b99a, 0xeac0c6e6, 0xe5b906e6,
- 0xe0ccdeeb, 0xdbfbb796, 0xd744fcc9, 0xd2a81d91, 0xce248c14, 0xc9b9bd85,
- 0xc5672a10, 0xc12c4cc9, 0xbd08a39e, 0xb8fbaf46, 0xb504f333, 0xb123f581,
- 0xad583ee9, 0xa9a15ab4, 0xa5fed6a9, 0xa2704302, 0x9ef5325f, 0x9b8d39b9,
- 0x9837f050, 0x94f4efa8, 0x91c3d373, 0x8ea4398a, 0x8b95c1e3, 0x88980e80,
- 0x85aac367, 0x82cd8698,
-};
-
-/*
- * Precomputed \Sum y^k { 1<=k<=n }. These are floor(true_value) to prevent
- * over-estimates when re-combining.
- */
-static const u32 runnable_avg_yN_sum[] = {
- 0, 1002, 1982, 2941, 3880, 4798, 5697, 6576, 7437, 8279, 9103,
- 9909,10698,11470,12226,12966,13690,14398,15091,15769,16433,17082,
- 17718,18340,18949,19545,20128,20698,21256,21802,22336,22859,23371,
-};
-
-/*
- * Precomputed \Sum y^k { 1<=k<=n, where n%32=0). Values are rolled down to
- * lower integers. See Documentation/scheduler/sched-avg.txt how these
- * were generated:
- */
-static const u32 __accumulated_sum_N32[] = {
- 0, 23371, 35056, 40899, 43820, 45281,
- 46011, 46376, 46559, 46650, 46696, 46719,
-};
-
/*
* Approximate:
* val * y^n, where y^32 ~= 0.5 (~1 scheduling period)
*/
-static __always_inline u64 decay_load(u64 val, u64 n)
+static u64 decay_load(u64 val, u64 n)
{
unsigned int local_n;
- if (!n)
- return val;
- else if (unlikely(n > LOAD_AVG_PERIOD * 63))
+ if (unlikely(n > LOAD_AVG_PERIOD * 63))
return 0;
/* after bounds checking we can collapse to 32-bit */
@@ -2795,30 +2757,97 @@ static __always_inline u64 decay_load(u64 val, u64 n)
return val;
}
+static u32 __accumulate_pelt_segments(u64 periods, u32 d1, u32 d3)
+{
+ u32 c1, c2, c3 = d3; /* y^0 == 1 */
+
+ /*
+ * c1 = d1 y^p
+ */
+ c1 = decay_load((u64)d1, periods);
+
+ /*
+ * p-1
+ * c2 = 1024 \Sum y^n
+ * n=1
+ *
+ * inf inf
+ * = 1024 ( \Sum y^n - \Sum y^n - y^0 )
+ * n=0 n=p
+ */
+ c2 = LOAD_AVG_MAX - decay_load(LOAD_AVG_MAX, periods) - 1024;
+
+ return c1 + c2 + c3;
+}
+
+#define cap_scale(v, s) ((v)*(s) >> SCHED_CAPACITY_SHIFT)
+
/*
- * For updates fully spanning n periods, the contribution to runnable
- * average will be: \Sum 1024*y^n
+ * Accumulate the three separate parts of the sum; d1 the remainder
+ * of the last (incomplete) period, d2 the span of full periods and d3
+ * the remainder of the (incomplete) current period.
+ *
+ * d1 d2 d3
+ * ^ ^ ^
+ * | | |
+ * |<->|<----------------->|<--->|
+ * ... |---x---|------| ... |------|-----x (now)
+ *
+ * p-1
+ * u' = (u + d1) y^p + 1024 \Sum y^n + d3 y^0
+ * n=1
*
- * We can compute this reasonably efficiently by combining:
- * y^PERIOD = 1/2 with precomputed \Sum 1024*y^n {for n <PERIOD}
+ * = u y^p + (Step 1)
+ *
+ * p-1
+ * d1 y^p + 1024 \Sum y^n + d3 y^0 (Step 2)
+ * n=1
*/
-static u32 __compute_runnable_contrib(u64 n)
+static __always_inline u32
+accumulate_sum(u64 delta, int cpu, struct sched_avg *sa,
+ unsigned long weight, int running, struct cfs_rq *cfs_rq)
{
- u32 contrib = 0;
+ unsigned long scale_freq, scale_cpu;
+ u32 contrib = (u32)delta; /* p == 0 -> delta < 1024 */
+ u64 periods;
- if (likely(n <= LOAD_AVG_PERIOD))
- return runnable_avg_yN_sum[n];
- else if (unlikely(n >= LOAD_AVG_MAX_N))
- return LOAD_AVG_MAX;
+ scale_freq = arch_scale_freq_capacity(NULL, cpu);
+ scale_cpu = arch_scale_cpu_capacity(NULL, cpu);
- /* Since n < LOAD_AVG_MAX_N, n/LOAD_AVG_PERIOD < 11 */
- contrib = __accumulated_sum_N32[n/LOAD_AVG_PERIOD];
- n %= LOAD_AVG_PERIOD;
- contrib = decay_load(contrib, n);
- return contrib + runnable_avg_yN_sum[n];
-}
+ delta += sa->period_contrib;
+ periods = delta / 1024; /* A period is 1024us (~1ms) */
-#define cap_scale(v, s) ((v)*(s) >> SCHED_CAPACITY_SHIFT)
+ /*
+ * Step 1: decay old *_sum if we crossed period boundaries.
+ */
+ if (periods) {
+ sa->load_sum = decay_load(sa->load_sum, periods);
+ if (cfs_rq) {
+ cfs_rq->runnable_load_sum =
+ decay_load(cfs_rq->runnable_load_sum, periods);
+ }
+ sa->util_sum = decay_load((u64)(sa->util_sum), periods);
+
+ /*
+ * Step 2
+ */
+ delta %= 1024;
+ contrib = __accumulate_pelt_segments(periods,
+ 1024 - sa->period_contrib, delta);
+ }
+ sa->period_contrib = delta;
+
+ contrib = cap_scale(contrib, scale_freq);
+ if (weight) {
+ sa->load_sum += weight * contrib;
+ if (cfs_rq)
+ cfs_rq->runnable_load_sum += weight * contrib;
+ }
+ if (running)
+ sa->util_sum += contrib * scale_cpu;
+
+ return periods;
+}
/*
* We can represent the historical contribution to runnable average as the
@@ -2849,13 +2878,10 @@ static u32 __compute_runnable_contrib(u64 n)
* = u_0 + u_1*y + u_2*y^2 + ... [re-labeling u_i --> u_{i+1}]
*/
static __always_inline int
-__update_load_avg(u64 now, int cpu, struct sched_avg *sa,
+___update_load_avg(u64 now, int cpu, struct sched_avg *sa,
unsigned long weight, int running, struct cfs_rq *cfs_rq)
{
- u64 delta, scaled_delta, periods;
- u32 contrib;
- unsigned int delta_w, scaled_delta_w, decayed = 0;
- unsigned long scale_freq, scale_cpu;
+ u64 delta;
delta = now - sa->last_update_time;
/*
@@ -2874,83 +2900,52 @@ __update_load_avg(u64 now, int cpu, struct sched_avg *sa,
delta >>= 10;
if (!delta)
return 0;
- sa->last_update_time = now;
-
- scale_freq = arch_scale_freq_capacity(NULL, cpu);
- scale_cpu = arch_scale_cpu_capacity(NULL, cpu);
-
- /* delta_w is the amount already accumulated against our next period */
- delta_w = sa->period_contrib;
- if (delta + delta_w >= 1024) {
- decayed = 1;
- /* how much left for next period will start over, we don't know yet */
- sa->period_contrib = 0;
+ sa->last_update_time += delta << 10;
- /*
- * Now that we know we're crossing a period boundary, figure
- * out how much from delta we need to complete the current
- * period and accrue it.
- */
- delta_w = 1024 - delta_w;
- scaled_delta_w = cap_scale(delta_w, scale_freq);
- if (weight) {
- sa->load_sum += weight * scaled_delta_w;
- if (cfs_rq) {
- cfs_rq->runnable_load_sum +=
- weight * scaled_delta_w;
- }
- }
- if (running)
- sa->util_sum += scaled_delta_w * scale_cpu;
-
- delta -= delta_w;
-
- /* Figure out how many additional periods this update spans */
- periods = delta / 1024;
- delta %= 1024;
+ /*
+ * Now we know we crossed measurement unit boundaries. The *_avg
+ * accrues by two steps:
+ *
+ * Step 1: accumulate *_sum since last_update_time. If we haven't
+ * crossed period boundaries, finish.
+ */
+ if (!accumulate_sum(delta, cpu, sa, weight, running, cfs_rq))
+ return 0;
- sa->load_sum = decay_load(sa->load_sum, periods + 1);
- if (cfs_rq) {
- cfs_rq->runnable_load_sum =
- decay_load(cfs_rq->runnable_load_sum, periods + 1);
- }
- sa->util_sum = decay_load((u64)(sa->util_sum), periods + 1);
-
- /* Efficiently calculate \sum (1..n_period) 1024*y^i */
- contrib = __compute_runnable_contrib(periods);
- contrib = cap_scale(contrib, scale_freq);
- if (weight) {
- sa->load_sum += weight * contrib;
- if (cfs_rq)
- cfs_rq->runnable_load_sum += weight * contrib;
- }
- if (running)
- sa->util_sum += contrib * scale_cpu;
+ /*
+ * Step 2: update *_avg.
+ */
+ sa->load_avg = div_u64(sa->load_sum, LOAD_AVG_MAX);
+ if (cfs_rq) {
+ cfs_rq->runnable_load_avg =
+ div_u64(cfs_rq->runnable_load_sum, LOAD_AVG_MAX);
}
+ sa->util_avg = sa->util_sum / LOAD_AVG_MAX;
- /* Remainder of delta accrued against u_0` */
- scaled_delta = cap_scale(delta, scale_freq);
- if (weight) {
- sa->load_sum += weight * scaled_delta;
- if (cfs_rq)
- cfs_rq->runnable_load_sum += weight * scaled_delta;
- }
- if (running)
- sa->util_sum += scaled_delta * scale_cpu;
+ return 1;
+}
- sa->period_contrib += delta;
+static int
+__update_load_avg_blocked_se(u64 now, int cpu, struct sched_entity *se)
+{
+ return ___update_load_avg(now, cpu, &se->avg, 0, 0, NULL);
+}
- if (decayed) {
- sa->load_avg = div_u64(sa->load_sum, LOAD_AVG_MAX);
- if (cfs_rq) {
- cfs_rq->runnable_load_avg =
- div_u64(cfs_rq->runnable_load_sum, LOAD_AVG_MAX);
- }
- sa->util_avg = sa->util_sum / LOAD_AVG_MAX;
- }
+static int
+__update_load_avg_se(u64 now, int cpu, struct cfs_rq *cfs_rq, struct sched_entity *se)
+{
+ return ___update_load_avg(now, cpu, &se->avg,
+ se->on_rq * scale_load_down(se->load.weight),
+ cfs_rq->curr == se, NULL);
+}
- return decayed;
+static int
+__update_load_avg_cfs_rq(u64 now, int cpu, struct cfs_rq *cfs_rq)
+{
+ return ___update_load_avg(now, cpu, &cfs_rq->avg,
+ scale_load_down(cfs_rq->load.weight),
+ cfs_rq->curr != NULL, cfs_rq);
}
/*
@@ -3014,6 +3009,9 @@ static inline void update_tg_load_avg(struct cfs_rq *cfs_rq, int force)
void set_task_rq_fair(struct sched_entity *se,
struct cfs_rq *prev, struct cfs_rq *next)
{
+ u64 p_last_update_time;
+ u64 n_last_update_time;
+
if (!sched_feat(ATTACH_AGE_LOAD))
return;
@@ -3024,11 +3022,11 @@ void set_task_rq_fair(struct sched_entity *se,
* time. This will result in the wakee task is less decayed, but giving
* the wakee more load sounds not bad.
*/
- if (se->avg.last_update_time && prev) {
- u64 p_last_update_time;
- u64 n_last_update_time;
+ if (!(se->avg.last_update_time && prev))
+ return;
#ifndef CONFIG_64BIT
+ {
u64 p_last_update_time_copy;
u64 n_last_update_time_copy;
@@ -3043,14 +3041,13 @@ void set_task_rq_fair(struct sched_entity *se,
} while (p_last_update_time != p_last_update_time_copy ||
n_last_update_time != n_last_update_time_copy);
+ }
#else
- p_last_update_time = prev->avg.last_update_time;
- n_last_update_time = next->avg.last_update_time;
+ p_last_update_time = prev->avg.last_update_time;
+ n_last_update_time = next->avg.last_update_time;
#endif
- __update_load_avg(p_last_update_time, cpu_of(rq_of(prev)),
- &se->avg, 0, 0, NULL);
- se->avg.last_update_time = n_last_update_time;
- }
+ __update_load_avg_blocked_se(p_last_update_time, cpu_of(rq_of(prev)), se);
+ se->avg.last_update_time = n_last_update_time;
}
/* Take into account change of utilization of a child task group */
@@ -3173,6 +3170,36 @@ static inline int propagate_entity_load_avg(struct sched_entity *se)
return 1;
}
+/*
+ * Check if we need to update the load and the utilization of a blocked
+ * group_entity:
+ */
+static inline bool skip_blocked_update(struct sched_entity *se)
+{
+ struct cfs_rq *gcfs_rq = group_cfs_rq(se);
+
+ /*
+ * If sched_entity still have not zero load or utilization, we have to
+ * decay it:
+ */
+ if (se->avg.load_avg || se->avg.util_avg)
+ return false;
+
+ /*
+ * If there is a pending propagation, we have to update the load and
+ * the utilization of the sched_entity:
+ */
+ if (gcfs_rq->propagate_avg)
+ return false;
+
+ /*
+ * Otherwise, the load and the utilization of the sched_entity is
+ * already zero and there is no pending propagation, so it will be a
+ * waste of time to try to decay it:
+ */
+ return true;
+}
+
#else /* CONFIG_FAIR_GROUP_SCHED */
static inline void update_tg_load_avg(struct cfs_rq *cfs_rq, int force) {}
@@ -3265,8 +3292,7 @@ update_cfs_rq_load_avg(u64 now, struct cfs_rq *cfs_rq, bool update_freq)
set_tg_cfs_propagate(cfs_rq);
}
- decayed = __update_load_avg(now, cpu_of(rq_of(cfs_rq)), sa,
- scale_load_down(cfs_rq->load.weight), cfs_rq->curr != NULL, cfs_rq);
+ decayed = __update_load_avg_cfs_rq(now, cpu_of(rq_of(cfs_rq)), cfs_rq);
#ifndef CONFIG_64BIT
smp_wmb();
@@ -3298,11 +3324,8 @@ static inline void update_load_avg(struct sched_entity *se, int flags)
* Track task load average for carrying it to new CPU after migrated, and
* track group sched_entity load average for task_h_load calc in migration
*/
- if (se->avg.last_update_time && !(flags & SKIP_AGE_LOAD)) {
- __update_load_avg(now, cpu, &se->avg,
- se->on_rq * scale_load_down(se->load.weight),
- cfs_rq->curr == se, NULL);
- }
+ if (se->avg.last_update_time && !(flags & SKIP_AGE_LOAD))
+ __update_load_avg_se(now, cpu, cfs_rq, se);
decayed = update_cfs_rq_load_avg(now, cfs_rq, true);
decayed |= propagate_entity_load_avg(se);
@@ -3407,7 +3430,7 @@ void sync_entity_load_avg(struct sched_entity *se)
u64 last_update_time;
last_update_time = cfs_rq_last_update_time(cfs_rq);
- __update_load_avg(last_update_time, cpu_of(rq_of(cfs_rq)), &se->avg, 0, 0, NULL);
+ __update_load_avg_blocked_se(last_update_time, cpu_of(rq_of(cfs_rq)), se);
}
/*
@@ -4271,8 +4294,9 @@ static u64 distribute_cfs_runtime(struct cfs_bandwidth *cfs_b,
list_for_each_entry_rcu(cfs_rq, &cfs_b->throttled_cfs_rq,
throttled_list) {
struct rq *rq = rq_of(cfs_rq);
+ struct rq_flags rf;
- raw_spin_lock(&rq->lock);
+ rq_lock(rq, &rf);
if (!cfs_rq_throttled(cfs_rq))
goto next;
@@ -4289,7 +4313,7 @@ static u64 distribute_cfs_runtime(struct cfs_bandwidth *cfs_b,
unthrottle_cfs_rq(cfs_rq);
next:
- raw_spin_unlock(&rq->lock);
+ rq_unlock(rq, &rf);
if (!remaining)
break;
@@ -5097,15 +5121,16 @@ void cpu_load_update_nohz_stop(void)
unsigned long curr_jiffies = READ_ONCE(jiffies);
struct rq *this_rq = this_rq();
unsigned long load;
+ struct rq_flags rf;
if (curr_jiffies == this_rq->last_load_update_tick)
return;
load = weighted_cpuload(cpu_of(this_rq));
- raw_spin_lock(&this_rq->lock);
+ rq_lock(this_rq, &rf);
update_rq_clock(this_rq);
cpu_load_update_nohz(this_rq, curr_jiffies, load);
- raw_spin_unlock(&this_rq->lock);
+ rq_unlock(this_rq, &rf);
}
#else /* !CONFIG_NO_HZ_COMMON */
static inline void cpu_load_update_nohz(struct rq *this_rq,
@@ -6769,7 +6794,7 @@ static void detach_task(struct task_struct *p, struct lb_env *env)
lockdep_assert_held(&env->src_rq->lock);
p->on_rq = TASK_ON_RQ_MIGRATING;
- deactivate_task(env->src_rq, p, 0);
+ deactivate_task(env->src_rq, p, DEQUEUE_NOCLOCK);
set_task_cpu(p, env->dst_cpu);
}
@@ -6902,7 +6927,7 @@ static void attach_task(struct rq *rq, struct task_struct *p)
lockdep_assert_held(&rq->lock);
BUG_ON(task_rq(p) != rq);
- activate_task(rq, p, 0);
+ activate_task(rq, p, ENQUEUE_NOCLOCK);
p->on_rq = TASK_ON_RQ_QUEUED;
check_preempt_curr(rq, p, 0);
}
@@ -6913,9 +6938,12 @@ static void attach_task(struct rq *rq, struct task_struct *p)
*/
static void attach_one_task(struct rq *rq, struct task_struct *p)
{
- raw_spin_lock(&rq->lock);
+ struct rq_flags rf;
+
+ rq_lock(rq, &rf);
+ update_rq_clock(rq);
attach_task(rq, p);
- raw_spin_unlock(&rq->lock);
+ rq_unlock(rq, &rf);
}
/*
@@ -6926,8 +6954,10 @@ static void attach_tasks(struct lb_env *env)
{
struct list_head *tasks = &env->tasks;
struct task_struct *p;
+ struct rq_flags rf;
- raw_spin_lock(&env->dst_rq->lock);
+ rq_lock(env->dst_rq, &rf);
+ update_rq_clock(env->dst_rq);
while (!list_empty(tasks)) {
p = list_first_entry(tasks, struct task_struct, se.group_node);
@@ -6936,7 +6966,7 @@ static void attach_tasks(struct lb_env *env)
attach_task(env->dst_rq, p);
}
- raw_spin_unlock(&env->dst_rq->lock);
+ rq_unlock(env->dst_rq, &rf);
}
#ifdef CONFIG_FAIR_GROUP_SCHED
@@ -6944,9 +6974,9 @@ static void update_blocked_averages(int cpu)
{
struct rq *rq = cpu_rq(cpu);
struct cfs_rq *cfs_rq;
- unsigned long flags;
+ struct rq_flags rf;
- raw_spin_lock_irqsave(&rq->lock, flags);
+ rq_lock_irqsave(rq, &rf);
update_rq_clock(rq);
/*
@@ -6954,6 +6984,8 @@ static void update_blocked_averages(int cpu)
* list_add_leaf_cfs_rq() for details.
*/
for_each_leaf_cfs_rq(rq, cfs_rq) {
+ struct sched_entity *se;
+
/* throttled entities do not contribute to load */
if (throttled_hierarchy(cfs_rq))
continue;
@@ -6961,11 +6993,12 @@ static void update_blocked_averages(int cpu)
if (update_cfs_rq_load_avg(cfs_rq_clock_task(cfs_rq), cfs_rq, true))
update_tg_load_avg(cfs_rq, 0);
- /* Propagate pending load changes to the parent */
- if (cfs_rq->tg->se[cpu])
- update_load_avg(cfs_rq->tg->se[cpu], 0);
+ /* Propagate pending load changes to the parent, if any: */
+ se = cfs_rq->tg->se[cpu];
+ if (se && !skip_blocked_update(se))
+ update_load_avg(se, 0);
}
- raw_spin_unlock_irqrestore(&rq->lock, flags);
+ rq_unlock_irqrestore(rq, &rf);
}
/*
@@ -7019,12 +7052,12 @@ static inline void update_blocked_averages(int cpu)
{
struct rq *rq = cpu_rq(cpu);
struct cfs_rq *cfs_rq = &rq->cfs;
- unsigned long flags;
+ struct rq_flags rf;
- raw_spin_lock_irqsave(&rq->lock, flags);
+ rq_lock_irqsave(rq, &rf);
update_rq_clock(rq);
update_cfs_rq_load_avg(cfs_rq_clock_task(cfs_rq), cfs_rq, true);
- raw_spin_unlock_irqrestore(&rq->lock, flags);
+ rq_unlock_irqrestore(rq, &rf);
}
static unsigned long task_h_load(struct task_struct *p)
@@ -7525,6 +7558,7 @@ static inline void update_sd_lb_stats(struct lb_env *env, struct sd_lb_stats *sd
{
struct sched_domain *child = env->sd->child;
struct sched_group *sg = env->sd->groups;
+ struct sg_lb_stats *local = &sds->local_stat;
struct sg_lb_stats tmp_sgs;
int load_idx, prefer_sibling = 0;
bool overload = false;
@@ -7541,7 +7575,7 @@ static inline void update_sd_lb_stats(struct lb_env *env, struct sd_lb_stats *sd
local_group = cpumask_test_cpu(env->dst_cpu, sched_group_cpus(sg));
if (local_group) {
sds->local = sg;
- sgs = &sds->local_stat;
+ sgs = local;
if (env->idle != CPU_NEWLY_IDLE ||
time_after_eq(jiffies, sg->sgc->next_update))
@@ -7565,8 +7599,8 @@ static inline void update_sd_lb_stats(struct lb_env *env, struct sd_lb_stats *sd
* the tasks on the system).
*/
if (prefer_sibling && sds->local &&
- group_has_capacity(env, &sds->local_stat) &&
- (sgs->sum_nr_running > 1)) {
+ group_has_capacity(env, local) &&
+ (sgs->sum_nr_running > local->sum_nr_running + 1)) {
sgs->group_no_capacity = 1;
sgs->group_type = group_classify(sg, sgs);
}
@@ -8042,7 +8076,7 @@ static int load_balance(int this_cpu, struct rq *this_rq,
struct sched_domain *sd_parent = sd->parent;
struct sched_group *group;
struct rq *busiest;
- unsigned long flags;
+ struct rq_flags rf;
struct cpumask *cpus = this_cpu_cpumask_var_ptr(load_balance_mask);
struct lb_env env = {
@@ -8105,7 +8139,7 @@ static int load_balance(int this_cpu, struct rq *this_rq,
env.loop_max = min(sysctl_sched_nr_migrate, busiest->nr_running);
more_balance:
- raw_spin_lock_irqsave(&busiest->lock, flags);
+ rq_lock_irqsave(busiest, &rf);
update_rq_clock(busiest);
/*
@@ -8122,14 +8156,14 @@ static int load_balance(int this_cpu, struct rq *this_rq,
* See task_rq_lock() family for the details.
*/
- raw_spin_unlock(&busiest->lock);
+ rq_unlock(busiest, &rf);
if (cur_ld_moved) {
attach_tasks(&env);
ld_moved += cur_ld_moved;
}
- local_irq_restore(flags);
+ local_irq_restore(rf.flags);
if (env.flags & LBF_NEED_BREAK) {
env.flags &= ~LBF_NEED_BREAK;
@@ -8207,6 +8241,8 @@ static int load_balance(int this_cpu, struct rq *this_rq,
sd->nr_balance_failed++;
if (need_active_balance(&env)) {
+ unsigned long flags;
+
raw_spin_lock_irqsave(&busiest->lock, flags);
/* don't kick the active_load_balance_cpu_stop,
@@ -8444,8 +8480,9 @@ static int active_load_balance_cpu_stop(void *data)
struct rq *target_rq = cpu_rq(target_cpu);
struct sched_domain *sd;
struct task_struct *p = NULL;
+ struct rq_flags rf;
- raw_spin_lock_irq(&busiest_rq->lock);
+ rq_lock_irq(busiest_rq, &rf);
/* make sure the requested cpu hasn't gone down in the meantime */
if (unlikely(busiest_cpu != smp_processor_id() ||
@@ -8496,7 +8533,7 @@ static int active_load_balance_cpu_stop(void *data)
rcu_read_unlock();
out_unlock:
busiest_rq->active_balance = 0;
- raw_spin_unlock(&busiest_rq->lock);
+ rq_unlock(busiest_rq, &rf);
if (p)
attach_one_task(target_rq, p);
@@ -8794,10 +8831,13 @@ static void nohz_idle_balance(struct rq *this_rq, enum cpu_idle_type idle)
* do the balance.
*/
if (time_after_eq(jiffies, rq->next_balance)) {
- raw_spin_lock_irq(&rq->lock);
+ struct rq_flags rf;
+
+ rq_lock_irq(rq, &rf);
update_rq_clock(rq);
cpu_load_update_idle(rq);
- raw_spin_unlock_irq(&rq->lock);
+ rq_unlock_irq(rq, &rf);
+
rebalance_domains(rq, CPU_IDLE);
}
@@ -8988,8 +9028,9 @@ static void task_fork_fair(struct task_struct *p)
struct cfs_rq *cfs_rq;
struct sched_entity *se = &p->se, *curr;
struct rq *rq = this_rq();
+ struct rq_flags rf;
- raw_spin_lock(&rq->lock);
+ rq_lock(rq, &rf);
update_rq_clock(rq);
cfs_rq = task_cfs_rq(current);
@@ -9010,7 +9051,7 @@ static void task_fork_fair(struct task_struct *p)
}
se->vruntime -= cfs_rq->min_vruntime;
- raw_spin_unlock(&rq->lock);
+ rq_unlock(rq, &rf);
}
/*
@@ -9372,7 +9413,6 @@ static DEFINE_MUTEX(shares_mutex);
int sched_group_set_shares(struct task_group *tg, unsigned long shares)
{
int i;
- unsigned long flags;
/*
* We can't change the weight of the root cgroup.
@@ -9389,19 +9429,17 @@ int sched_group_set_shares(struct task_group *tg, unsigned long shares)
tg->shares = shares;
for_each_possible_cpu(i) {
struct rq *rq = cpu_rq(i);
- struct sched_entity *se;
+ struct sched_entity *se = tg->se[i];
+ struct rq_flags rf;
- se = tg->se[i];
/* Propagate contribution to hierarchy */
- raw_spin_lock_irqsave(&rq->lock, flags);
-
- /* Possible calls to update_curr() need rq clock */
+ rq_lock_irqsave(rq, &rf);
update_rq_clock(rq);
for_each_sched_entity(se) {
update_load_avg(se, UPDATE_TG);
update_cfs_shares(se);
}
- raw_spin_unlock_irqrestore(&rq->lock, flags);
+ rq_unlock_irqrestore(rq, &rf);
}
done:
diff --git a/kernel/sched/features.h b/kernel/sched/features.h
index 1b3c8189b286..11192e0cb122 100644
--- a/kernel/sched/features.h
+++ b/kernel/sched/features.h
@@ -56,6 +56,13 @@ SCHED_FEAT(TTWU_QUEUE, true)
*/
SCHED_FEAT(SIS_AVG_CPU, false)
+/*
+ * Issue a WARN when we do multiple update_rq_clock() calls
+ * in a single rq->lock section. Default disabled because the
+ * annotations are not complete.
+ */
+SCHED_FEAT(WARN_DOUBLE_CLOCK, false)
+
#ifdef HAVE_RT_PUSH_IPI
/*
* In order to avoid a thundering herd attack of CPUs that are
diff --git a/kernel/sched/rt.c b/kernel/sched/rt.c
index 9f3e40226dec..979b7341008a 100644
--- a/kernel/sched/rt.c
+++ b/kernel/sched/rt.c
@@ -1927,6 +1927,87 @@ static int find_next_push_cpu(struct rq *rq)
#define RT_PUSH_IPI_EXECUTING 1
#define RT_PUSH_IPI_RESTART 2
+/*
+ * When a high priority task schedules out from a CPU and a lower priority
+ * task is scheduled in, a check is made to see if there's any RT tasks
+ * on other CPUs that are waiting to run because a higher priority RT task
+ * is currently running on its CPU. In this case, the CPU with multiple RT
+ * tasks queued on it (overloaded) needs to be notified that a CPU has opened
+ * up that may be able to run one of its non-running queued RT tasks.
+ *
+ * On large CPU boxes, there's the case that several CPUs could schedule
+ * a lower priority task at the same time, in which case it will look for
+ * any overloaded CPUs that it could pull a task from. To do this, the runqueue
+ * lock must be taken from that overloaded CPU. Having 10s of CPUs all fighting
+ * for a single overloaded CPU's runqueue lock can produce a large latency.
+ * (This has actually been observed on large boxes running cyclictest).
+ * Instead of taking the runqueue lock of the overloaded CPU, each of the
+ * CPUs that scheduled a lower priority task simply sends an IPI to the
+ * overloaded CPU. An IPI is much cheaper than taking an runqueue lock with
+ * lots of contention. The overloaded CPU will look to push its non-running
+ * RT task off, and if it does, it can then ignore the other IPIs coming
+ * in, and just pass those IPIs off to any other overloaded CPU.
+ *
+ * When a CPU schedules a lower priority task, it only sends an IPI to
+ * the "next" CPU that has overloaded RT tasks. This prevents IPI storms,
+ * as having 10 CPUs scheduling lower priority tasks and 10 CPUs with
+ * RT overloaded tasks, would cause 100 IPIs to go out at once.
+ *
+ * The overloaded RT CPU, when receiving an IPI, will try to push off its
+ * overloaded RT tasks and then send an IPI to the next CPU that has
+ * overloaded RT tasks. This stops when all CPUs with overloaded RT tasks
+ * have completed. Just because a CPU may have pushed off its own overloaded
+ * RT task does not mean it should stop sending the IPI around to other
+ * overloaded CPUs. There may be another RT task waiting to run on one of
+ * those CPUs that are of higher priority than the one that was just
+ * pushed.
+ *
+ * An optimization that could possibly be made is to make a CPU array similar
+ * to the cpupri array mask of all running RT tasks, but for the overloaded
+ * case, then the IPI could be sent to only the CPU with the highest priority
+ * RT task waiting, and that CPU could send off further IPIs to the CPU with
+ * the next highest waiting task. Since the overloaded case is much less likely
+ * to happen, the complexity of this implementation may not be worth it.
+ * Instead, just send an IPI around to all overloaded CPUs.
+ *
+ * The rq->rt.push_flags holds the status of the IPI that is going around.
+ * A run queue can only send out a single IPI at a time. The possible flags
+ * for rq->rt.push_flags are:
+ *
+ * (None or zero): No IPI is going around for the current rq
+ * RT_PUSH_IPI_EXECUTING: An IPI for the rq is being passed around
+ * RT_PUSH_IPI_RESTART: The priority of the running task for the rq
+ * has changed, and the IPI should restart
+ * circulating the overloaded CPUs again.
+ *
+ * rq->rt.push_cpu contains the CPU that is being sent the IPI. It is updated
+ * before sending to the next CPU.
+ *
+ * Instead of having all CPUs that schedule a lower priority task send
+ * an IPI to the same "first" CPU in the RT overload mask, they send it
+ * to the next overloaded CPU after their own CPU. This helps distribute
+ * the work when there's more than one overloaded CPU and multiple CPUs
+ * scheduling in lower priority tasks.
+ *
+ * When a rq schedules a lower priority task than what was currently
+ * running, the next CPU with overloaded RT tasks is examined first.
+ * That is, if CPU 1 and 5 are overloaded, and CPU 3 schedules a lower
+ * priority task, it will send an IPI first to CPU 5, then CPU 5 will
+ * send to CPU 1 if it is still overloaded. CPU 1 will clear the
+ * rq->rt.push_flags if RT_PUSH_IPI_RESTART is not set.
+ *
+ * The first CPU to notice IPI_RESTART is set, will clear that flag and then
+ * send an IPI to the next overloaded CPU after the rq->cpu and not the next
+ * CPU after push_cpu. That is, if CPU 1, 4 and 5 are overloaded when CPU 3
+ * schedules a lower priority task, and the IPI_RESTART gets set while the
+ * handling is being done on CPU 5, it will clear the flag and send it back to
+ * CPU 4 instead of CPU 1.
+ *
+ * Note, the above logic can be disabled by turning off the sched_feature
+ * RT_PUSH_IPI. Then the rq lock of the overloaded CPU will simply be
+ * taken by the CPU requesting a pull and the waiting RT task will be pulled
+ * by that CPU. This may be fine for machines with few CPUs.
+ */
static void tell_cpu_to_push(struct rq *rq)
{
int cpu;
diff --git a/kernel/sched/sched-pelt.h b/kernel/sched/sched-pelt.h
new file mode 100644
index 000000000000..cd200d16529e
--- /dev/null
+++ b/kernel/sched/sched-pelt.h
@@ -0,0 +1,13 @@
+/* Generated by Documentation/scheduler/sched-pelt; do not modify. */
+
+static const u32 runnable_avg_yN_inv[] = {
+ 0xffffffff, 0xfa83b2da, 0xf5257d14, 0xefe4b99a, 0xeac0c6e6, 0xe5b906e6,
+ 0xe0ccdeeb, 0xdbfbb796, 0xd744fcc9, 0xd2a81d91, 0xce248c14, 0xc9b9bd85,
+ 0xc5672a10, 0xc12c4cc9, 0xbd08a39e, 0xb8fbaf46, 0xb504f333, 0xb123f581,
+ 0xad583ee9, 0xa9a15ab4, 0xa5fed6a9, 0xa2704302, 0x9ef5325f, 0x9b8d39b9,
+ 0x9837f050, 0x94f4efa8, 0x91c3d373, 0x8ea4398a, 0x8b95c1e3, 0x88980e80,
+ 0x85aac367, 0x82cd8698,
+};
+
+#define LOAD_AVG_PERIOD 32
+#define LOAD_AVG_MAX 47742
diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h
index 5cbf92214ad8..de4b934ba974 100644
--- a/kernel/sched/sched.h
+++ b/kernel/sched/sched.h
@@ -1331,15 +1331,17 @@ extern const u32 sched_prio_to_wmult[40];
#define DEQUEUE_SLEEP 0x01
#define DEQUEUE_SAVE 0x02 /* matches ENQUEUE_RESTORE */
#define DEQUEUE_MOVE 0x04 /* matches ENQUEUE_MOVE */
+#define DEQUEUE_NOCLOCK 0x08 /* matches ENQUEUE_NOCLOCK */
#define ENQUEUE_WAKEUP 0x01
#define ENQUEUE_RESTORE 0x02
#define ENQUEUE_MOVE 0x04
+#define ENQUEUE_NOCLOCK 0x08
-#define ENQUEUE_HEAD 0x08
-#define ENQUEUE_REPLENISH 0x10
+#define ENQUEUE_HEAD 0x10
+#define ENQUEUE_REPLENISH 0x20
#ifdef CONFIG_SMP
-#define ENQUEUE_MIGRATED 0x20
+#define ENQUEUE_MIGRATED 0x40
#else
#define ENQUEUE_MIGRATED 0x00
#endif
@@ -1624,6 +1626,7 @@ static inline void sched_avg_update(struct rq *rq) { }
struct rq *__task_rq_lock(struct task_struct *p, struct rq_flags *rf)
__acquires(rq->lock);
+
struct rq *task_rq_lock(struct task_struct *p, struct rq_flags *rf)
__acquires(p->pi_lock)
__acquires(rq->lock);
@@ -1645,6 +1648,62 @@ task_rq_unlock(struct rq *rq, struct task_struct *p, struct rq_flags *rf)
raw_spin_unlock_irqrestore(&p->pi_lock, rf->flags);
}
+static inline void
+rq_lock_irqsave(struct rq *rq, struct rq_flags *rf)
+ __acquires(rq->lock)
+{
+ raw_spin_lock_irqsave(&rq->lock, rf->flags);
+ rq_pin_lock(rq, rf);
+}
+
+static inline void
+rq_lock_irq(struct rq *rq, struct rq_flags *rf)
+ __acquires(rq->lock)
+{
+ raw_spin_lock_irq(&rq->lock);
+ rq_pin_lock(rq, rf);
+}
+
+static inline void
+rq_lock(struct rq *rq, struct rq_flags *rf)
+ __acquires(rq->lock)
+{
+ raw_spin_lock(&rq->lock);
+ rq_pin_lock(rq, rf);
+}
+
+static inline void
+rq_relock(struct rq *rq, struct rq_flags *rf)
+ __acquires(rq->lock)
+{
+ raw_spin_lock(&rq->lock);
+ rq_repin_lock(rq, rf);
+}
+
+static inline void
+rq_unlock_irqrestore(struct rq *rq, struct rq_flags *rf)
+ __releases(rq->lock)
+{
+ rq_unpin_lock(rq, rf);
+ raw_spin_unlock_irqrestore(&rq->lock, rf->flags);
+}
+
+static inline void
+rq_unlock_irq(struct rq *rq, struct rq_flags *rf)
+ __releases(rq->lock)
+{
+ rq_unpin_lock(rq, rf);
+ raw_spin_unlock_irq(&rq->lock);
+}
+
+static inline void
+rq_unlock(struct rq *rq, struct rq_flags *rf)
+ __releases(rq->lock)
+{
+ rq_unpin_lock(rq, rf);
+ raw_spin_unlock(&rq->lock);
+}
+
#ifdef CONFIG_SMP
#ifdef CONFIG_PREEMPT
diff --git a/kernel/softirq.c b/kernel/softirq.c
index 744fa611cae0..4e09821f9d9e 100644
--- a/kernel/softirq.c
+++ b/kernel/softirq.c
@@ -309,7 +309,7 @@ asmlinkage __visible void __softirq_entry __do_softirq(void)
account_irq_exit_time(current);
__local_bh_enable(SOFTIRQ_OFFSET);
WARN_ON_ONCE(in_interrupt());
- tsk_restore_flags(current, old_flags, PF_MEMALLOC);
+ current_restore_flags(old_flags, PF_MEMALLOC);
}
asmlinkage __visible void do_softirq(void)
diff --git a/kernel/workqueue.c b/kernel/workqueue.c
index c0168b7da1ea..5bf1be018628 100644
--- a/kernel/workqueue.c
+++ b/kernel/workqueue.c
@@ -4735,6 +4735,29 @@ long work_on_cpu(int cpu, long (*fn)(void *), void *arg)
return wfc.ret;
}
EXPORT_SYMBOL_GPL(work_on_cpu);
+
+/**
+ * work_on_cpu_safe - run a function in thread context on a particular cpu
+ * @cpu: the cpu to run on
+ * @fn: the function to run
+ * @arg: the function argument
+ *
+ * Disables CPU hotplug and calls work_on_cpu(). The caller must not hold
+ * any locks which would prevent @fn from completing.
+ *
+ * Return: The value @fn returns.
+ */
+long work_on_cpu_safe(int cpu, long (*fn)(void *), void *arg)
+{
+ long ret = -ENODEV;
+
+ get_online_cpus();
+ if (cpu_online(cpu))
+ ret = work_on_cpu(cpu, fn, arg);
+ put_online_cpus();
+ return ret;
+}
+EXPORT_SYMBOL_GPL(work_on_cpu_safe);
#endif /* CONFIG_SMP */
#ifdef CONFIG_FREEZER
diff --git a/net/core/dev.c b/net/core/dev.c
index 7869ae3837ca..e8a366387a99 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -4240,7 +4240,7 @@ static int __netif_receive_skb(struct sk_buff *skb)
*/
current->flags |= PF_MEMALLOC;
ret = __netif_receive_skb_core(skb, true);
- tsk_restore_flags(current, pflags, PF_MEMALLOC);
+ current_restore_flags(pflags, PF_MEMALLOC);
} else
ret = __netif_receive_skb_core(skb, false);
diff --git a/net/core/sock.c b/net/core/sock.c
index 2c4f574168fb..b416a537bd0a 100644
--- a/net/core/sock.c
+++ b/net/core/sock.c
@@ -325,7 +325,7 @@ int __sk_backlog_rcv(struct sock *sk, struct sk_buff *skb)
current->flags |= PF_MEMALLOC;
ret = sk->sk_backlog_rcv(sk, skb);
- tsk_restore_flags(current, pflags, PF_MEMALLOC);
+ current_restore_flags(pflags, PF_MEMALLOC);
return ret;
}
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