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Date: Thu, 16 Jul 2015 16:33:44 -0400
From: kan.liang@...el.com
To: a.p.zijlstra@...llo.nl
Cc: mingo@...hat.com, acme@...nel.org, eranian@...gle.com,
ak@...ux.intel.com, mark.rutland@....com, adrian.hunter@...el.com,
dsahern@...il.com, jolsa@...nel.org, namhyung@...nel.org,
linux-kernel@...r.kernel.org, Kan Liang <kan.liang@...el.com>
Subject: [PATCH 2/9] perf/x86: core_misc PMU disable and enable support
From: Kan Liang <kan.liang@...el.com>
This patch implements core_misc PMU disable and enable functions.
core_misc PMU counters are free running counters, so it's impossible to
stop/start them. The "disable" means not read counters.
With disable/enable functions, it's possible to "disable" core_misc
events when other PMU events stop. For example, we are able to stop
read the core_misc counter during irq handler.
Signed-off-by: Kan Liang <kan.liang@...el.com>
---
arch/x86/include/asm/perf_event.h | 2 ++
arch/x86/kernel/cpu/perf_event.h | 10 ++++++
arch/x86/kernel/cpu/perf_event_intel.c | 4 +++
arch/x86/kernel/cpu/perf_event_intel_core_misc.c | 41 ++++++++++++++++++++++++
4 files changed, 57 insertions(+)
diff --git a/arch/x86/include/asm/perf_event.h b/arch/x86/include/asm/perf_event.h
index dc0f6ed..2905f4c 100644
--- a/arch/x86/include/asm/perf_event.h
+++ b/arch/x86/include/asm/perf_event.h
@@ -11,6 +11,8 @@
#define X86_PMC_IDX_MAX 64
+#define X86_CORE_MISC_COUNTER_MAX 64
+
#define MSR_ARCH_PERFMON_PERFCTR0 0xc1
#define MSR_ARCH_PERFMON_PERFCTR1 0xc2
diff --git a/arch/x86/kernel/cpu/perf_event.h b/arch/x86/kernel/cpu/perf_event.h
index 3e7fd27..fb14f8a 100644
--- a/arch/x86/kernel/cpu/perf_event.h
+++ b/arch/x86/kernel/cpu/perf_event.h
@@ -239,6 +239,12 @@ struct cpu_hw_events {
int excl_thread_id; /* 0 or 1 */
/*
+ * Intel core misc
+ */
+ struct perf_event *core_misc_events[X86_CORE_MISC_COUNTER_MAX]; /* in counter order */
+ unsigned long core_misc_active_mask[BITS_TO_LONGS(X86_CORE_MISC_COUNTER_MAX)];
+
+ /*
* AMD specific bits
*/
struct amd_nb *amd_nb;
@@ -927,6 +933,10 @@ int p6_pmu_init(void);
int knc_pmu_init(void);
+void intel_core_misc_pmu_enable(void);
+
+void intel_core_misc_pmu_disable(void);
+
ssize_t events_sysfs_show(struct device *dev, struct device_attribute *attr,
char *page);
diff --git a/arch/x86/kernel/cpu/perf_event_intel.c b/arch/x86/kernel/cpu/perf_event_intel.c
index b9826a9..651a86d 100644
--- a/arch/x86/kernel/cpu/perf_event_intel.c
+++ b/arch/x86/kernel/cpu/perf_event_intel.c
@@ -1586,6 +1586,8 @@ static int intel_pmu_handle_irq(struct pt_regs *regs)
if (!x86_pmu.late_ack)
apic_write(APIC_LVTPC, APIC_DM_NMI);
__intel_pmu_disable_all();
+ if (cpuc->core_misc_active_mask)
+ intel_core_misc_pmu_disable();
handled = intel_pmu_drain_bts_buffer();
handled += intel_bts_interrupt();
status = intel_pmu_get_status();
@@ -1671,6 +1673,8 @@ again:
done:
__intel_pmu_enable_all(0, true);
+ if (cpuc->core_misc_active_mask)
+ intel_core_misc_pmu_enable();
/*
* Only unmask the NMI after the overflow counters
* have been reset. This avoids spurious NMIs on
diff --git a/arch/x86/kernel/cpu/perf_event_intel_core_misc.c b/arch/x86/kernel/cpu/perf_event_intel_core_misc.c
index c6c82ac..4efe842 100644
--- a/arch/x86/kernel/cpu/perf_event_intel_core_misc.c
+++ b/arch/x86/kernel/cpu/perf_event_intel_core_misc.c
@@ -250,12 +250,19 @@ static void __core_misc_pmu_event_start(struct core_misc_pmu *pmu,
static void core_misc_pmu_event_start(struct perf_event *event, int mode)
{
struct core_misc_pmu *pmu = get_core_misc_pmu(event);
+ struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
+ int idx = event->hw.idx;
unsigned long flags;
if (pmu == NULL)
return;
spin_lock_irqsave(&pmu->lock, flags);
+
+ if (pmu->pmu->type == perf_intel_core_misc_thread) {
+ cpuc->core_misc_events[idx] = event;
+ __set_bit(idx, cpuc->core_misc_active_mask);
+ }
__core_misc_pmu_event_start(pmu, event);
spin_unlock_irqrestore(&pmu->lock, flags);
}
@@ -264,6 +271,7 @@ static void core_misc_pmu_event_stop(struct perf_event *event, int mode)
{
struct core_misc_pmu *pmu = get_core_misc_pmu(event);
struct hw_perf_event *hwc = &event->hw;
+ struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
unsigned long flags;
if (pmu == NULL)
@@ -273,6 +281,8 @@ static void core_misc_pmu_event_stop(struct perf_event *event, int mode)
/* mark event as deactivated and stopped */
if (!(hwc->state & PERF_HES_STOPPED)) {
+ if (__test_and_clear_bit(hwc->idx, cpuc->core_misc_active_mask))
+ cpuc->core_misc_events[hwc->idx] = NULL;
WARN_ON_ONCE(pmu->n_active <= 0);
pmu->n_active--;
@@ -294,6 +304,32 @@ static void core_misc_pmu_event_stop(struct perf_event *event, int mode)
spin_unlock_irqrestore(&pmu->lock, flags);
}
+void intel_core_misc_pmu_enable(void)
+{
+ struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
+ struct perf_event *event;
+ u64 start;
+ int bit;
+
+ for_each_set_bit(bit, cpuc->core_misc_active_mask,
+ X86_CORE_MISC_COUNTER_MAX) {
+ event = cpuc->core_misc_events[bit];
+ start = core_misc_pmu_read_counter(event);
+ local64_set(&event->hw.prev_count, start);
+ }
+}
+
+void intel_core_misc_pmu_disable(void)
+{
+ struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
+ int bit;
+
+ for_each_set_bit(bit, cpuc->core_misc_active_mask,
+ X86_CORE_MISC_COUNTER_MAX) {
+ core_misc_pmu_event_update(cpuc->core_misc_events[bit]);
+ }
+}
+
static void core_misc_pmu_event_del(struct perf_event *event, int mode)
{
core_misc_pmu_event_stop(event, PERF_EF_UPDATE);
@@ -863,6 +899,11 @@ static void __init core_misc_pmus_register(void)
.capabilities = PERF_PMU_CAP_NO_INTERRUPT,
};
+ if (type->type == perf_intel_core_misc_thread) {
+ type->pmu.pmu_disable = (void *) intel_core_misc_pmu_disable;
+ type->pmu.pmu_enable = (void *) intel_core_misc_pmu_enable;
+ }
+
err = perf_pmu_register(&type->pmu, type->name, -1);
if (WARN_ON(err))
pr_info("Failed to register PMU %s error %d\n",
--
1.8.3.1
--
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