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Message-ID: <4D94EF4B.6070905@gmail.com>
Date: Fri, 01 Apr 2011 01:16:59 +0400
From: Cyrill Gorcunov <gorcunov@...il.com>
To: lkml <linux-kernel@...r.kernel.org>
CC: Ingo Molnar <mingo@...e.hu>, Lin Ming <ming.m.lin@...el.com>,
Peter Zijlstra <a.p.zijlstra@...llo.nl>,
Arnaldo Carvalho de Melo <acme@...hat.com>,
Frederic Weisbecker <fweisbec@...il.com>
Subject: [RFC] [PATCH] perf, x86: Add PERF_COUNT_HW_NMI_WATCHDOG event
Because of Netburst HW restriction we can't move events arbitrary
between counters and this makes 'perf top' unable to run if nmi-watchdog
is running (since both uses PERF_COUNT_HW_CPU_CYCLES but such event is
bound to run on a few counters only). So as a workaround we could count that named
non-sleeping ticks (as oprofile does) and both perf top and nmi-watchdog would co-exsist
without conflicts but kernel needs to know about such specifics -- so PERF_COUNT_HW_NMI_WATCHDOG
event is introduced. This event is an alias of PERF_COUNT_HW_CPU_CYCLES for non-P4 x86
architecture so nothing much changed I think.
Please review, I might be missing something. Also comments on idea is quite welcome since
it touches ABI part.
---
>From b86ba38cb258bd309d96aee5b7b25c69945a2b60 Mon Sep 17 00:00:00 2001
From: Cyrill Gorcunov <gorcunov@...il.com>
Date: Sun, 27 Mar 2011 19:58:30 +0400
Subject: [PATCH] perf, x86: Add PERF_COUNT_HW_NMI_WATCHDOG event
Due to restriction and specifics of Netburst PMU we need
a separated event for NMI watchdog. Note that on all other
than P4 PMU cpus this event is a simple alias for PERF_COUNT_HW_CPU_CYCLES.
Signed-off-by: Cyrill Gorcunov <gorcunov@...il.com>
CC: Ingo Molnar <mingo@...hat.com>
CC: Peter Zijlstra <a.p.zijlstra@...llo.nl>
Tested-by: Lin Ming <ming.m.lin@...el.com>
Acked-by: Don Zickus <dzickus@...hat.com>
---
arch/x86/kernel/cpu/perf_event_amd.c | 1 +
arch/x86/kernel/cpu/perf_event_intel.c | 1 +
arch/x86/kernel/cpu/perf_event_p4.c | 15 +++++++++++++++
arch/x86/kernel/cpu/perf_event_p6.c | 1 +
include/linux/perf_event.h | 1 +
kernel/watchdog.c | 2 +-
6 files changed, 20 insertions(+), 1 deletions(-)
diff --git a/arch/x86/kernel/cpu/perf_event_amd.c b/arch/x86/kernel/cpu/perf_event_amd.c
index 461f62b..248d8d7 100644
--- a/arch/x86/kernel/cpu/perf_event_amd.c
+++ b/arch/x86/kernel/cpu/perf_event_amd.c
@@ -102,6 +102,7 @@ static const u64 amd_perfmon_event_map[] =
[PERF_COUNT_HW_CACHE_MISSES] = 0x0081,
[PERF_COUNT_HW_BRANCH_INSTRUCTIONS] = 0x00c2,
[PERF_COUNT_HW_BRANCH_MISSES] = 0x00c3,
+ [PERF_COUNT_HW_NMI_WATCHDOG] = 0x0076,
};
static u64 amd_pmu_event_map(int hw_event)
diff --git a/arch/x86/kernel/cpu/perf_event_intel.c b/arch/x86/kernel/cpu/perf_event_intel.c
index 8fc2b2c..53b4790 100644
--- a/arch/x86/kernel/cpu/perf_event_intel.c
+++ b/arch/x86/kernel/cpu/perf_event_intel.c
@@ -34,6 +34,7 @@ static const u64 intel_perfmon_event_map[] =
[PERF_COUNT_HW_BRANCH_INSTRUCTIONS] = 0x00c4,
[PERF_COUNT_HW_BRANCH_MISSES] = 0x00c5,
[PERF_COUNT_HW_BUS_CYCLES] = 0x013c,
+ [PERF_COUNT_HW_NMI_WATCHDOG] = 0x003c,
};
static struct event_constraint intel_core_event_constraints[] =
diff --git a/arch/x86/kernel/cpu/perf_event_p4.c b/arch/x86/kernel/cpu/perf_event_p4.c
index 8ff882f..ef65c94 100644
--- a/arch/x86/kernel/cpu/perf_event_p4.c
+++ b/arch/x86/kernel/cpu/perf_event_p4.c
@@ -557,6 +557,7 @@ static __initconst const u64 p4_hw_cache_event_ids
};
static u64 p4_general_events[PERF_COUNT_HW_MAX] = {
+
/* non-halted CPU clocks */
[PERF_COUNT_HW_CPU_CYCLES] =
p4_config_pack_escr(P4_ESCR_EVENT(P4_EVENT_GLOBAL_POWER_EVENTS) |
@@ -607,6 +608,20 @@ static u64 p4_general_events[PERF_COUNT_HW_MAX] = {
P4_ESCR_EMASK_BIT(P4_EVENT_FSB_DATA_ACTIVITY, DRDY_DRV) |
P4_ESCR_EMASK_BIT(P4_EVENT_FSB_DATA_ACTIVITY, DRDY_OWN)) |
p4_config_pack_cccr(P4_CCCR_EDGE | P4_CCCR_COMPARE),
+
+ /* we use that named non-sleeping calls */
+ [PERF_COUNT_HW_NMI_WATCHDOG] =
+ 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 struct p4_event_bind *p4_config_get_bind(u64 config)
diff --git a/arch/x86/kernel/cpu/perf_event_p6.c b/arch/x86/kernel/cpu/perf_event_p6.c
index 20c097e..3daeb18 100644
--- a/arch/x86/kernel/cpu/perf_event_p6.c
+++ b/arch/x86/kernel/cpu/perf_event_p6.c
@@ -12,6 +12,7 @@ static const u64 p6_perfmon_event_map[] =
[PERF_COUNT_HW_BRANCH_INSTRUCTIONS] = 0x00c4,
[PERF_COUNT_HW_BRANCH_MISSES] = 0x00c5,
[PERF_COUNT_HW_BUS_CYCLES] = 0x0062,
+ [PERF_COUNT_HW_NMI_WATCHDOG] = 0x0079,
};
static u64 p6_pmu_event_map(int hw_event)
diff --git a/include/linux/perf_event.h b/include/linux/perf_event.h
index 04d75a8..78da67d 100644
--- a/include/linux/perf_event.h
+++ b/include/linux/perf_event.h
@@ -52,6 +52,7 @@ enum perf_hw_id {
PERF_COUNT_HW_BRANCH_INSTRUCTIONS = 4,
PERF_COUNT_HW_BRANCH_MISSES = 5,
PERF_COUNT_HW_BUS_CYCLES = 6,
+ PERF_COUNT_HW_NMI_WATCHDOG = 7,
PERF_COUNT_HW_MAX, /* non-ABI */
};
diff --git a/kernel/watchdog.c b/kernel/watchdog.c
index 140dce7..46a849a 100644
--- a/kernel/watchdog.c
+++ b/kernel/watchdog.c
@@ -191,7 +191,7 @@ static int is_softlockup(unsigned long touch_ts)
#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_NMI_WATCHDOG,
.size = sizeof(struct perf_event_attr),
.pinned = 1,
.disabled = 1,
--
1.7.3.3
--
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