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Message-ID: <tip-9de8d686955b0e8e27847ed4edbbcd280f3fd853@git.kernel.org>
Date: Mon, 29 Feb 2016 03:12:51 -0800
From: tip-bot for Thomas Gleixner <tipbot@...or.com>
To: linux-tip-commits@...r.kernel.org
Cc: harish.chegondi@...el.com, andi.kleen@...el.com, bp@...en8.de,
tglx@...utronix.de, torvalds@...ux-foundation.org,
peterz@...radead.org, jacob.jun.pan@...ux.intel.com,
vincent.weaver@...ne.edu, eranian@...gle.com, jolsa@...hat.com,
kan.liang@...el.com, linux-kernel@...r.kernel.org,
mingo@...nel.org, hpa@...or.com, acme@...hat.com
Subject: [tip:perf/core] perf/x86/intel/rapl: Convert it to a per package
facility
Commit-ID: 9de8d686955b0e8e27847ed4edbbcd280f3fd853
Gitweb: http://git.kernel.org/tip/9de8d686955b0e8e27847ed4edbbcd280f3fd853
Author: Thomas Gleixner <tglx@...utronix.de>
AuthorDate: Mon, 22 Feb 2016 22:19:26 +0000
Committer: Ingo Molnar <mingo@...nel.org>
CommitDate: Mon, 29 Feb 2016 09:35:26 +0100
perf/x86/intel/rapl: Convert it to a per package facility
RAPL is a per package facility and we already have a mechanism for a dedicated
per package reader. So there is no point to have multiple CPUs doing the
same. The current implementation actually starts two timers on two CPUs if one
does:
perf stat -C1,2 -e -e power/energy-pkg ....
which makes the whole concept of 1 reader per package moot.
What's worse is that the above returns the double of the actual energy
consumption, but that's a different problem to address and cannot be solved by
removing the pointless per cpuness of that mechanism.
Signed-off-by: Thomas Gleixner <tglx@...utronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@...radead.org>
Cc: Andi Kleen <andi.kleen@...el.com>
Cc: Arnaldo Carvalho de Melo <acme@...hat.com>
Cc: Borislav Petkov <bp@...en8.de>
Cc: Harish Chegondi <harish.chegondi@...el.com>
Cc: Jacob Pan <jacob.jun.pan@...ux.intel.com>
Cc: Jiri Olsa <jolsa@...hat.com>
Cc: Kan Liang <kan.liang@...el.com>
Cc: Linus Torvalds <torvalds@...ux-foundation.org>
Cc: Peter Zijlstra <peterz@...radead.org>
Cc: Stephane Eranian <eranian@...gle.com>
Cc: Vince Weaver <vincent.weaver@...ne.edu>
Cc: linux-kernel@...r.kernel.org
Link: http://lkml.kernel.org/r/20160222221012.845369524@linutronix.de
Signed-off-by: Ingo Molnar <mingo@...nel.org>
---
arch/x86/events/intel/rapl.c | 194 +++++++++++++++++++------------------------
1 file changed, 86 insertions(+), 108 deletions(-)
diff --git a/arch/x86/events/intel/rapl.c b/arch/x86/events/intel/rapl.c
index 753d90c..019e541 100644
--- a/arch/x86/events/intel/rapl.c
+++ b/arch/x86/events/intel/rapl.c
@@ -129,15 +129,23 @@ struct rapl_pmu {
struct hrtimer hrtimer;
};
+struct rapl_pmus {
+ struct pmu pmu;
+ unsigned int maxpkg;
+ struct rapl_pmu *pmus[];
+};
+
/* 1/2^hw_unit Joule */
static int rapl_hw_unit[NR_RAPL_DOMAINS] __read_mostly;
-static struct pmu rapl_pmu_class;
+static struct rapl_pmus *rapl_pmus;
static cpumask_t rapl_cpu_mask;
-static int rapl_cntr_mask;
+static unsigned int rapl_cntr_mask;
static u64 rapl_timer_ms;
-static DEFINE_PER_CPU(struct rapl_pmu *, rapl_pmu);
-static DEFINE_PER_CPU(struct rapl_pmu *, rapl_pmu_to_free);
+static inline struct rapl_pmu *cpu_to_rapl_pmu(unsigned int cpu)
+{
+ return rapl_pmus->pmus[topology_logical_package_id(cpu)];
+}
static inline u64 rapl_read_counter(struct perf_event *event)
{
@@ -317,12 +325,12 @@ static void rapl_pmu_event_del(struct perf_event *event, int flags)
static int rapl_pmu_event_init(struct perf_event *event)
{
- struct rapl_pmu *pmu = __this_cpu_read(rapl_pmu);
u64 cfg = event->attr.config & RAPL_EVENT_MASK;
int bit, msr, ret = 0;
+ struct rapl_pmu *pmu;
/* only look at RAPL events */
- if (event->attr.type != rapl_pmu_class.type)
+ if (event->attr.type != rapl_pmus->pmu.type)
return -ENOENT;
/* check only supported bits are set */
@@ -370,6 +378,7 @@ static int rapl_pmu_event_init(struct perf_event *event)
return -EINVAL;
/* must be done before validate_group */
+ pmu = cpu_to_rapl_pmu(event->cpu);
event->cpu = pmu->cpu;
event->pmu_private = pmu;
event->hw.event_base = msr;
@@ -502,116 +511,62 @@ const struct attribute_group *rapl_attr_groups[] = {
NULL,
};
-static struct pmu rapl_pmu_class = {
- .attr_groups = rapl_attr_groups,
- .task_ctx_nr = perf_invalid_context, /* system-wide only */
- .event_init = rapl_pmu_event_init,
- .add = rapl_pmu_event_add, /* must have */
- .del = rapl_pmu_event_del, /* must have */
- .start = rapl_pmu_event_start,
- .stop = rapl_pmu_event_stop,
- .read = rapl_pmu_event_read,
-};
-
static void rapl_cpu_exit(int cpu)
{
- struct rapl_pmu *pmu = per_cpu(rapl_pmu, cpu);
- int i, phys_id = topology_physical_package_id(cpu);
- int target = -1;
+ struct rapl_pmu *pmu = cpu_to_rapl_pmu(cpu);
+ int target;
- /* find a new cpu on same package */
- for_each_online_cpu(i) {
- if (i == cpu)
- continue;
- if (phys_id == topology_physical_package_id(i)) {
- target = i;
- break;
- }
- }
- /*
- * clear cpu from cpumask
- * if was set in cpumask and still some cpu on package,
- * then move to new cpu
- */
- if (cpumask_test_and_clear_cpu(cpu, &rapl_cpu_mask) && target >= 0)
- cpumask_set_cpu(target, &rapl_cpu_mask);
+ /* Check if exiting cpu is used for collecting rapl events */
+ if (!cpumask_test_and_clear_cpu(cpu, &rapl_cpu_mask))
+ return;
- WARN_ON(cpumask_empty(&rapl_cpu_mask));
- /*
- * migrate events and context to new cpu
- */
- if (target >= 0)
- perf_pmu_migrate_context(pmu->pmu, cpu, target);
+ pmu->cpu = -1;
+ /* Find a new cpu to collect rapl events */
+ target = cpumask_any_but(topology_core_cpumask(cpu), cpu);
- /* cancel overflow polling timer for CPU */
- hrtimer_cancel(&pmu->hrtimer);
+ /* Migrate rapl events to the new target */
+ if (target < nr_cpu_ids) {
+ cpumask_set_cpu(target, &rapl_cpu_mask);
+ pmu->cpu = target;
+ perf_pmu_migrate_context(pmu->pmu, cpu, target);
+ }
}
static void rapl_cpu_init(int cpu)
{
- int i, phys_id = topology_physical_package_id(cpu);
+ struct rapl_pmu *pmu = cpu_to_rapl_pmu(cpu);
+ int target;
+
+ /*
+ * Check if there is an online cpu in the package which collects rapl
+ * events already.
+ */
+ target = cpumask_any_and(&rapl_cpu_mask, topology_core_cpumask(cpu));
+ if (target < nr_cpu_ids)
+ return;
- /* check if phys_is is already covered */
- for_each_cpu(i, &rapl_cpu_mask) {
- if (phys_id == topology_physical_package_id(i))
- return;
- }
- /* was not found, so add it */
cpumask_set_cpu(cpu, &rapl_cpu_mask);
+ pmu->cpu = cpu;
}
static int rapl_cpu_prepare(int cpu)
{
- struct rapl_pmu *pmu = per_cpu(rapl_pmu, cpu);
- int phys_id = topology_physical_package_id(cpu);
+ struct rapl_pmu *pmu = cpu_to_rapl_pmu(cpu);
if (pmu)
return 0;
- if (phys_id < 0)
- return -1;
-
pmu = kzalloc_node(sizeof(*pmu), GFP_KERNEL, cpu_to_node(cpu));
if (!pmu)
- return -1;
- raw_spin_lock_init(&pmu->lock);
+ return -ENOMEM;
+ raw_spin_lock_init(&pmu->lock);
INIT_LIST_HEAD(&pmu->active_list);
-
- pmu->pmu = &rapl_pmu_class;
- pmu->cpu = cpu;
-
+ pmu->pmu = &rapl_pmus->pmu;
pmu->timer_interval = ms_to_ktime(rapl_timer_ms);
-
+ pmu->cpu = -1;
rapl_hrtimer_init(pmu);
-
- /* set RAPL pmu for this cpu for now */
- per_cpu(rapl_pmu, cpu) = pmu;
- per_cpu(rapl_pmu_to_free, cpu) = NULL;
-
- return 0;
-}
-
-static void rapl_cpu_kfree(int cpu)
-{
- struct rapl_pmu *pmu = per_cpu(rapl_pmu_to_free, cpu);
-
- kfree(pmu);
-
- per_cpu(rapl_pmu_to_free, cpu) = NULL;
-}
-
-static int rapl_cpu_dying(int cpu)
-{
- struct rapl_pmu *pmu = per_cpu(rapl_pmu, cpu);
-
- if (!pmu)
- return 0;
-
- per_cpu(rapl_pmu, cpu) = NULL;
-
- per_cpu(rapl_pmu_to_free, cpu) = pmu;
-
+ rapl_pmus->pmus[topology_logical_package_id(cpu)] = pmu;
return 0;
}
@@ -624,24 +579,16 @@ static int rapl_cpu_notifier(struct notifier_block *self,
case CPU_UP_PREPARE:
rapl_cpu_prepare(cpu);
break;
- case CPU_STARTING:
- rapl_cpu_init(cpu);
- break;
- case CPU_UP_CANCELED:
- case CPU_DYING:
- rapl_cpu_dying(cpu);
- break;
+
+ case CPU_DOWN_FAILED:
case CPU_ONLINE:
- case CPU_DEAD:
- rapl_cpu_kfree(cpu);
+ rapl_cpu_init(cpu);
break;
+
case CPU_DOWN_PREPARE:
rapl_cpu_exit(cpu);
break;
- default:
- break;
}
-
return NOTIFY_OK;
}
@@ -703,10 +650,14 @@ static void __init rapl_advertise(void)
static int __init rapl_prepare_cpus(void)
{
- unsigned int cpu;
+ unsigned int cpu, pkg;
int ret;
for_each_online_cpu(cpu) {
+ pkg = topology_logical_package_id(cpu);
+ if (rapl_pmus->pmus[pkg])
+ continue;
+
ret = rapl_cpu_prepare(cpu);
if (ret)
return ret;
@@ -717,10 +668,33 @@ static int __init rapl_prepare_cpus(void)
static void __init cleanup_rapl_pmus(void)
{
- int cpu;
+ int i;
+
+ for (i = 0; i < rapl_pmus->maxpkg; i++)
+ kfree(rapl_pmus->pmus + i);
+ kfree(rapl_pmus);
+}
- for_each_online_cpu(cpu)
- kfree(per_cpu(rapl_pmu, cpu));
+static int __init init_rapl_pmus(void)
+{
+ int maxpkg = topology_max_packages();
+ size_t size;
+
+ size = sizeof(*rapl_pmus) + maxpkg * sizeof(struct rapl_pmu *);
+ rapl_pmus = kzalloc(size, GFP_KERNEL);
+ if (!rapl_pmus)
+ return -ENOMEM;
+
+ rapl_pmus->maxpkg = maxpkg;
+ rapl_pmus->pmu.attr_groups = rapl_attr_groups;
+ rapl_pmus->pmu.task_ctx_nr = perf_invalid_context;
+ rapl_pmus->pmu.event_init = rapl_pmu_event_init;
+ rapl_pmus->pmu.add = rapl_pmu_event_add;
+ rapl_pmus->pmu.del = rapl_pmu_event_del;
+ rapl_pmus->pmu.start = rapl_pmu_event_start;
+ rapl_pmus->pmu.stop = rapl_pmu_event_stop;
+ rapl_pmus->pmu.read = rapl_pmu_event_read;
+ return 0;
}
static const struct x86_cpu_id rapl_cpu_match[] __initconst = {
@@ -771,13 +745,17 @@ static int __init rapl_pmu_init(void)
if (ret)
return ret;
+ ret = init_rapl_pmus();
+ if (ret)
+ return ret;
+
cpu_notifier_register_begin();
ret = rapl_prepare_cpus();
if (ret)
goto out;
- ret = perf_pmu_register(&rapl_pmu_class, "power", -1);
+ ret = perf_pmu_register(&rapl_pmus->pmu, "power", -1);
if (ret)
goto out;
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