[GIT pull] perf fixes for 4.8

From: Thomas Gleixner
Date: Sat Sep 24 2016 - 15:35:47 EST


Linus,

please pull the latest perf-urgent-for-linus git tree from:

git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git perf-urgent-for-linus

Three fixlets for perf:

- Add a missing NULL pointer check in the intel BTS driver.

- Make BTS an exclusive PMU because BTS can only handle one event at a
time

- Ensure that exclusive events are limited to one PMU so that several
exclusive events can be scheduled on different PMU instances.

Thanks,

tglx

------------------>
Alexander Shishkin (2):
perf/x86/intel/bts: Make it an exclusive PMU
perf/core: Limit matching exclusive events to one PMU

Sebastian Andrzej Siewior (1):
perf/x86/intel/bts: Make sure debug store is valid


arch/x86/events/intel/bts.c | 5 +++--
kernel/events/core.c | 2 +-
2 files changed, 4 insertions(+), 3 deletions(-)

diff --git a/arch/x86/events/intel/bts.c b/arch/x86/events/intel/bts.c
index bdcd6510992c..982c9e31daca 100644
--- a/arch/x86/events/intel/bts.c
+++ b/arch/x86/events/intel/bts.c
@@ -455,7 +455,7 @@ int intel_bts_interrupt(void)
* The only surefire way of knowing if this NMI is ours is by checking
* the write ptr against the PMI threshold.
*/
- if (ds->bts_index >= ds->bts_interrupt_threshold)
+ if (ds && (ds->bts_index >= ds->bts_interrupt_threshold))
handled = 1;

/*
@@ -584,7 +584,8 @@ static __init int bts_init(void)
if (!boot_cpu_has(X86_FEATURE_DTES64) || !x86_pmu.bts)
return -ENODEV;

- bts_pmu.capabilities = PERF_PMU_CAP_AUX_NO_SG | PERF_PMU_CAP_ITRACE;
+ bts_pmu.capabilities = PERF_PMU_CAP_AUX_NO_SG | PERF_PMU_CAP_ITRACE |
+ PERF_PMU_CAP_EXCLUSIVE;
bts_pmu.task_ctx_nr = perf_sw_context;
bts_pmu.event_init = bts_event_init;
bts_pmu.add = bts_event_add;
diff --git a/kernel/events/core.c b/kernel/events/core.c
index a54f2c2cdb20..fc9bb2225291 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -3929,7 +3929,7 @@ static void exclusive_event_destroy(struct perf_event *event)

static bool exclusive_event_match(struct perf_event *e1, struct perf_event *e2)
{
- if ((e1->pmu->capabilities & PERF_PMU_CAP_EXCLUSIVE) &&
+ if ((e1->pmu == e2->pmu) &&
(e1->cpu == e2->cpu ||
e1->cpu == -1 ||
e2->cpu == -1))