Re: [RFC -tip] perf, x86: Add PERF_COUNT_HW_NMI_WATCHDOG event v2
From: Cyrill Gorcunov
Date: Wed Jun 22 2011 - 04:28:14 EST
On Tue, Jun 21, 2011 at 10:32:27PM +0400, Cyrill Gorcunov wrote:
> On Tue, Jun 21, 2011 at 08:06:54PM +0200, Stephane Eranian wrote:
> ...
> >
> > If in arch/x86/kernel/cpu/perf_event.c I add a callback which
> > checks:
> >
> > if (netburst_host) {
> > attr.type = PERF_TYPE_RAW
> > attr.config = 0x3c
> > } else {
> > attr.type = PERF_TYPE_HARDWARE
> > attr.config = PERF_COUNT_HW__CPU_CYCLES
> > }
> >
> > I simply don't think PERF_COUNT_HW_NMI_WATCHDOG should
> > ever be exposed to users.
>
> yes, and peterz pointed it out as well, i agree of course.
>
What about something like below?
Cyrill
---
arch/x86/kernel/cpu/perf_event.c | 15 +++++++++++++++
arch/x86/kernel/cpu/perf_event_amd.c | 1 +
arch/x86/kernel/cpu/perf_event_intel.c | 2 ++
arch/x86/kernel/cpu/perf_event_p4.c | 27 +++++++++++++++++++++++++++
arch/x86/kernel/cpu/perf_event_p6.c | 1 +
include/linux/perf_event.h | 6 ++++++
kernel/watchdog.c | 2 +-
7 files changed, 53 insertions(+), 1 deletion(-)
Index: linux-2.6.git/arch/x86/kernel/cpu/perf_event.c
===================================================================
--- linux-2.6.git.orig/arch/x86/kernel/cpu/perf_event.c
+++ linux-2.6.git/arch/x86/kernel/cpu/perf_event.c
@@ -233,6 +233,7 @@ struct x86_pmu {
void (*enable_all)(int added);
void (*enable)(struct perf_event *);
void (*disable)(struct perf_event *);
+ void (*hw_watchdog_config)(struct perf_event *event);
int (*hw_config)(struct perf_event *event);
int (*schedule_events)(struct cpu_hw_events *cpuc, int n, int *assign);
unsigned eventsel;
@@ -413,6 +414,17 @@ static int x86_pmu_extra_regs(u64 config
return 0;
}
+static void x86_pmu_hw_watchdog_config(struct perf_event *event)
+{
+ /*
+ * On most x86 architectures watchdog cycles
+ * are the same as cpu cycles.
+ */
+ if (event->attr.type == PERF_TYPE_HARDWARE &&
+ event->attr.config == PERF_COUNT_HW_NMI_WATCHDOG)
+ event->attr.config = PERF_COUNT_HW_CPU_CYCLES;
+}
+
static atomic_t active_events;
static DEFINE_MUTEX(pmc_reserve_mutex);
@@ -706,6 +718,9 @@ static int __x86_pmu_event_init(struct p
event->hw.last_cpu = -1;
event->hw.last_tag = ~0ULL;
+ if (x86_pmu.hw_watchdog_config)
+ x86_pmu.hw_watchdog_config(event);
+
return x86_pmu.hw_config(event);
}
Index: linux-2.6.git/arch/x86/kernel/cpu/perf_event_amd.c
===================================================================
--- linux-2.6.git.orig/arch/x86/kernel/cpu/perf_event_amd.c
+++ linux-2.6.git/arch/x86/kernel/cpu/perf_event_amd.c
@@ -372,6 +372,7 @@ static __initconst const struct x86_pmu
.enable_all = x86_pmu_enable_all,
.enable = x86_pmu_enable_event,
.disable = x86_pmu_disable_event,
+ .hw_watchdog_config = x86_pmu_hw_watchdog_config,
.hw_config = amd_pmu_hw_config,
.schedule_events = x86_schedule_events,
.eventsel = MSR_K7_EVNTSEL0,
Index: linux-2.6.git/arch/x86/kernel/cpu/perf_event_intel.c
===================================================================
--- linux-2.6.git.orig/arch/x86/kernel/cpu/perf_event_intel.c
+++ linux-2.6.git/arch/x86/kernel/cpu/perf_event_intel.c
@@ -1213,6 +1213,7 @@ static __initconst const struct x86_pmu
.enable_all = x86_pmu_enable_all,
.enable = x86_pmu_enable_event,
.disable = x86_pmu_disable_event,
+ .hw_watchdog_config = x86_pmu_hw_watchdog_config,
.hw_config = x86_pmu_hw_config,
.schedule_events = x86_schedule_events,
.eventsel = MSR_ARCH_PERFMON_EVENTSEL0,
@@ -1298,6 +1299,7 @@ static __initconst const struct x86_pmu
.enable_all = intel_pmu_enable_all,
.enable = intel_pmu_enable_event,
.disable = intel_pmu_disable_event,
+ .hw_watchdog_config = x86_pmu_hw_watchdog_config,
.hw_config = intel_pmu_hw_config,
.schedule_events = x86_schedule_events,
.eventsel = MSR_ARCH_PERFMON_EVENTSEL0,
Index: linux-2.6.git/arch/x86/kernel/cpu/perf_event_p4.c
===================================================================
--- linux-2.6.git.orig/arch/x86/kernel/cpu/perf_event_p4.c
+++ linux-2.6.git/arch/x86/kernel/cpu/perf_event_p4.c
@@ -705,6 +705,32 @@ static int p4_validate_raw_event(struct
return 0;
}
+static void p4_hw_watchdog_config(struct perf_event *event)
+{
+ /*
+ * Watchdog ticks are special on Netburst, we use
+ * that named "non-sleeping" ticks as recommended
+ * by Intel SDM Vol3b.
+ */
+ if (event->attr.type != PERF_TYPE_HARDWARE ||
+ event->attr.config != PERF_COUNT_HW_NMI_WATCHDOG)
+ return;
+
+ event->attr.type = PERF_TYPE_RAW;
+ event->attr.config =
+ p4_config_pack_escr(P4_ESCR_EVENT(P4_EVENT_EXECUTION_EVENT) |
+ P4_ESCR_EMASK_BIT(P4_EVENT_EXECUTION_EVENT, NBOGUS0) |
+ P4_ESCR_EMASK_BIT(P4_EVENT_EXECUTION_EVENT, NBOGUS1) |
+ P4_ESCR_EMASK_BIT(P4_EVENT_EXECUTION_EVENT, NBOGUS2) |
+ P4_ESCR_EMASK_BIT(P4_EVENT_EXECUTION_EVENT, NBOGUS3) |
+ P4_ESCR_EMASK_BIT(P4_EVENT_EXECUTION_EVENT, BOGUS0) |
+ P4_ESCR_EMASK_BIT(P4_EVENT_EXECUTION_EVENT, BOGUS1) |
+ P4_ESCR_EMASK_BIT(P4_EVENT_EXECUTION_EVENT, BOGUS2) |
+ P4_ESCR_EMASK_BIT(P4_EVENT_EXECUTION_EVENT, BOGUS3)) |
+ p4_config_pack_cccr(P4_CCCR_THRESHOLD(15) | P4_CCCR_COMPLEMENT |
+ P4_CCCR_COMPARE),
+}
+
static int p4_hw_config(struct perf_event *event)
{
int cpu = get_cpu();
@@ -1179,6 +1205,7 @@ static __initconst const struct x86_pmu
.cntval_bits = ARCH_P4_CNTRVAL_BITS,
.cntval_mask = ARCH_P4_CNTRVAL_MASK,
.max_period = (1ULL << (ARCH_P4_CNTRVAL_BITS - 1)) - 1,
+ .hw_watchdog_config = p4_hw_watchdog_config,
.hw_config = p4_hw_config,
.schedule_events = p4_pmu_schedule_events,
/*
Index: linux-2.6.git/arch/x86/kernel/cpu/perf_event_p6.c
===================================================================
--- linux-2.6.git.orig/arch/x86/kernel/cpu/perf_event_p6.c
+++ linux-2.6.git/arch/x86/kernel/cpu/perf_event_p6.c
@@ -91,6 +91,7 @@ static __initconst const struct x86_pmu
.enable_all = p6_pmu_enable_all,
.enable = p6_pmu_enable_event,
.disable = p6_pmu_disable_event,
+ .hw_watchdog_config = x86_pmu_hw_watchdog_config,
.hw_config = x86_pmu_hw_config,
.schedule_events = x86_schedule_events,
.eventsel = MSR_P6_EVNTSEL0,
Index: linux-2.6.git/include/linux/perf_event.h
===================================================================
--- linux-2.6.git.orig/include/linux/perf_event.h
+++ linux-2.6.git/include/linux/perf_event.h
@@ -582,6 +582,12 @@ struct hw_perf_event {
};
/*
+ * Watchdog cycles are special on some architectures (such as Netburst)
+ * and because of that it must be unique among enum perf_hw_id.
+ */
+#define PERF_COUNT_HW_WATCHDOG_CYCLES (PERF_COUNT_HW_MAX + 1)
+
+/*
* hw_perf_event::state flags
*/
#define PERF_HES_STOPPED 0x01 /* the counter is stopped */
Index: linux-2.6.git/kernel/watchdog.c
===================================================================
--- linux-2.6.git.orig/kernel/watchdog.c
+++ linux-2.6.git/kernel/watchdog.c
@@ -202,7 +202,7 @@ static int is_softlockup(unsigned long t
#ifdef CONFIG_HARDLOCKUP_DETECTOR
static struct perf_event_attr wd_hw_attr = {
.type = PERF_TYPE_HARDWARE,
- .config = PERF_COUNT_HW_CPU_CYCLES,
+ .config = PERF_COUNT_HW_WATCHDOG_CYCLES,
.size = sizeof(struct perf_event_attr),
.pinned = 1,
.disabled = 1,
--
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