[GIT PULL] perf fixes
From: Ingo Molnar
Date: Fri Apr 29 2011 - 14:17:31 EST
Linus,
Please pull the latest perf-fixes-for-linus git tree from:
git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip.git perf-fixes-for-linus
Thanks,
Ingo
------------------>
Don Zickus (1):
perf, x86, nmi: Move LVT un-masking into irq handlers
Ingo Molnar (1):
perf events, x86: Work around the Nehalem AAJ80 erratum
Michal Simek (1):
ftrace: Build without frame pointers on Microblaze
Peter Zijlstra (1):
perf, x86: Fix BTS condition
arch/x86/kernel/cpu/perf_event.c | 16 ++++++++++++----
arch/x86/kernel/cpu/perf_event_intel.c | 29 +++++++++++++++++++++++++++--
arch/x86/kernel/cpu/perf_event_p4.c | 17 +++++++++++++----
kernel/trace/Kconfig | 2 +-
4 files changed, 53 insertions(+), 11 deletions(-)
diff --git a/arch/x86/kernel/cpu/perf_event.c b/arch/x86/kernel/cpu/perf_event.c
index 632e5dc..e638689 100644
--- a/arch/x86/kernel/cpu/perf_event.c
+++ b/arch/x86/kernel/cpu/perf_event.c
@@ -613,8 +613,8 @@ static int x86_setup_perfctr(struct perf_event *event)
/*
* Branch tracing:
*/
- if ((attr->config == PERF_COUNT_HW_BRANCH_INSTRUCTIONS) &&
- (hwc->sample_period == 1)) {
+ if (attr->config == PERF_COUNT_HW_BRANCH_INSTRUCTIONS &&
+ !attr->freq && hwc->sample_period == 1) {
/* BTS is not supported by this architecture. */
if (!x86_pmu.bts_active)
return -EOPNOTSUPP;
@@ -1288,6 +1288,16 @@ static int x86_pmu_handle_irq(struct pt_regs *regs)
cpuc = &__get_cpu_var(cpu_hw_events);
+ /*
+ * Some chipsets need to unmask the LVTPC in a particular spot
+ * inside the nmi handler. As a result, the unmasking was pushed
+ * into all the nmi handlers.
+ *
+ * This generic handler doesn't seem to have any issues where the
+ * unmasking occurs so it was left at the top.
+ */
+ apic_write(APIC_LVTPC, APIC_DM_NMI);
+
for (idx = 0; idx < x86_pmu.num_counters; idx++) {
if (!test_bit(idx, cpuc->active_mask)) {
/*
@@ -1374,8 +1384,6 @@ perf_event_nmi_handler(struct notifier_block *self,
return NOTIFY_DONE;
}
- apic_write(APIC_LVTPC, APIC_DM_NMI);
-
handled = x86_pmu.handle_irq(args->regs);
if (!handled)
return NOTIFY_DONE;
diff --git a/arch/x86/kernel/cpu/perf_event_intel.c b/arch/x86/kernel/cpu/perf_event_intel.c
index 43fa20b..e61539b 100644
--- a/arch/x86/kernel/cpu/perf_event_intel.c
+++ b/arch/x86/kernel/cpu/perf_event_intel.c
@@ -25,7 +25,7 @@ struct intel_percore {
/*
* Intel PerfMon, used on Core and later.
*/
-static const u64 intel_perfmon_event_map[] =
+static u64 intel_perfmon_event_map[PERF_COUNT_HW_MAX] __read_mostly =
{
[PERF_COUNT_HW_CPU_CYCLES] = 0x003c,
[PERF_COUNT_HW_INSTRUCTIONS] = 0x00c0,
@@ -933,6 +933,16 @@ static int intel_pmu_handle_irq(struct pt_regs *regs)
cpuc = &__get_cpu_var(cpu_hw_events);
+ /*
+ * Some chipsets need to unmask the LVTPC in a particular spot
+ * inside the nmi handler. As a result, the unmasking was pushed
+ * into all the nmi handlers.
+ *
+ * This handler doesn't seem to have any issues with the unmasking
+ * so it was left at the top.
+ */
+ apic_write(APIC_LVTPC, APIC_DM_NMI);
+
intel_pmu_disable_all();
handled = intel_pmu_drain_bts_buffer();
status = intel_pmu_get_status();
@@ -998,6 +1008,9 @@ intel_bts_constraints(struct perf_event *event)
struct hw_perf_event *hwc = &event->hw;
unsigned int hw_event, bts_event;
+ if (event->attr.freq)
+ return NULL;
+
hw_event = hwc->config & INTEL_ARCH_EVENT_MASK;
bts_event = x86_pmu.event_map(PERF_COUNT_HW_BRANCH_INSTRUCTIONS);
@@ -1305,7 +1318,7 @@ static void intel_clovertown_quirks(void)
* AJ106 could possibly be worked around by not allowing LBR
* usage from PEBS, including the fixup.
* AJ68 could possibly be worked around by always programming
- * a pebs_event_reset[0] value and coping with the lost events.
+ * a pebs_event_reset[0] value and coping with the lost events.
*
* But taken together it might just make sense to not enable PEBS on
* these chips.
@@ -1409,6 +1422,18 @@ static __init int intel_pmu_init(void)
x86_pmu.percore_constraints = intel_nehalem_percore_constraints;
x86_pmu.enable_all = intel_pmu_nhm_enable_all;
x86_pmu.extra_regs = intel_nehalem_extra_regs;
+
+ if (ebx & 0x40) {
+ /*
+ * Erratum AAJ80 detected, we work it around by using
+ * the BR_MISP_EXEC.ANY event. This will over-count
+ * branch-misses, but it's still much better than the
+ * architectural event which is often completely bogus:
+ */
+ intel_perfmon_event_map[PERF_COUNT_HW_BRANCH_MISSES] = 0x7f89;
+
+ pr_cont("erratum AAJ80 worked around, ");
+ }
pr_cont("Nehalem events, ");
break;
diff --git a/arch/x86/kernel/cpu/perf_event_p4.c b/arch/x86/kernel/cpu/perf_event_p4.c
index d1f77e2..e93fcd5 100644
--- a/arch/x86/kernel/cpu/perf_event_p4.c
+++ b/arch/x86/kernel/cpu/perf_event_p4.c
@@ -950,11 +950,20 @@ static int p4_pmu_handle_irq(struct pt_regs *regs)
x86_pmu_stop(event, 0);
}
- if (handled) {
- /* p4 quirk: unmask it again */
- apic_write(APIC_LVTPC, apic_read(APIC_LVTPC) & ~APIC_LVT_MASKED);
+ if (handled)
inc_irq_stat(apic_perf_irqs);
- }
+
+ /*
+ * When dealing with the unmasking of the LVTPC on P4 perf hw, it has
+ * been observed that the OVF bit flag has to be cleared first _before_
+ * the LVTPC can be unmasked.
+ *
+ * The reason is the NMI line will continue to be asserted while the OVF
+ * bit is set. This causes a second NMI to generate if the LVTPC is
+ * unmasked before the OVF bit is cleared, leading to unknown NMI
+ * messages.
+ */
+ apic_write(APIC_LVTPC, APIC_DM_NMI);
return handled;
}
diff --git a/kernel/trace/Kconfig b/kernel/trace/Kconfig
index 61d7d59f..2ad39e5 100644
--- a/kernel/trace/Kconfig
+++ b/kernel/trace/Kconfig
@@ -141,7 +141,7 @@ if FTRACE
config FUNCTION_TRACER
bool "Kernel Function Tracer"
depends on HAVE_FUNCTION_TRACER
- select FRAME_POINTER if !ARM_UNWIND && !S390
+ select FRAME_POINTER if !ARM_UNWIND && !S390 && !MICROBLAZE
select KALLSYMS
select GENERIC_TRACER
select CONTEXT_SWITCH_TRACER
--
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