aboutsummaryrefslogtreecommitdiff
diff options
context:
space:
mode:
authorAndrew Murray <[email protected]>2019-01-10 13:53:25 +0000
committerIngo Molnar <[email protected]>2019-01-21 11:01:20 +0100
commitcc6795aeffea0a80d0baf9ad31ba926a6c42cef5 (patch)
tree8969ffe42449ae873b5195ae0cfb19e4b70bf04f
parent486efe9f8e30bac1e236f867df164f4966f3e207 (diff)
perf/core: Add PERF_PMU_CAP_NO_EXCLUDE for exclusion incapable PMUs
Many PMU drivers do not have the capability to exclude counting events that occur in specific contexts such as idle, kernel, guest, etc. These drivers indicate this by returning an error in their event_init upon testing the events attribute flags. This approach is error prone and often inconsistent. Let's instead allow PMU drivers to advertise their inability to exclude based on context via a new capability: PERF_PMU_CAP_NO_EXCLUDE. This allows the perf core to reject requests for exclusion events where there is no support in the PMU. Signed-off-by: Andrew Murray <[email protected]> Signed-off-by: Peter Zijlstra (Intel) <[email protected]> Cc: Arnaldo Carvalho de Melo <[email protected]> Cc: Benjamin Herrenschmidt <[email protected]> Cc: Borislav Petkov <[email protected]> Cc: Ivan Kokshaysky <[email protected]> Cc: Linus Torvalds <[email protected]> Cc: Mark Rutland <[email protected]> Cc: Matt Turner <[email protected]> Cc: Michael Ellerman <[email protected]> Cc: Paul Mackerras <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Richard Henderson <[email protected]> Cc: Russell King <[email protected]> Cc: Sascha Hauer <[email protected]> Cc: Shawn Guo <[email protected]> Cc: Thomas Gleixner <[email protected]> Cc: Will Deacon <[email protected]> Cc: [email protected] Cc: [email protected] Cc: [email protected] Cc: [email protected] Link: https://lkml.kernel.org/r/[email protected] Signed-off-by: Ingo Molnar <[email protected]>
-rw-r--r--include/linux/perf_event.h1
-rw-r--r--kernel/events/core.c9
2 files changed, 10 insertions, 0 deletions
diff --git a/include/linux/perf_event.h b/include/linux/perf_event.h
index 54a78d22f0a6..cec02dc63b51 100644
--- a/include/linux/perf_event.h
+++ b/include/linux/perf_event.h
@@ -244,6 +244,7 @@ struct perf_event;
#define PERF_PMU_CAP_EXCLUSIVE 0x10
#define PERF_PMU_CAP_ITRACE 0x20
#define PERF_PMU_CAP_HETEROGENEOUS_CPUS 0x40
+#define PERF_PMU_CAP_NO_EXCLUDE 0x80
/**
* struct pmu - generic performance monitoring unit
diff --git a/kernel/events/core.c b/kernel/events/core.c
index 3cd13a30f732..fbe59b793b36 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -9772,6 +9772,15 @@ static int perf_try_init_event(struct pmu *pmu, struct perf_event *event)
if (ctx)
perf_event_ctx_unlock(event->group_leader, ctx);
+ if (!ret) {
+ if (pmu->capabilities & PERF_PMU_CAP_NO_EXCLUDE &&
+ event_has_any_exclude_flag(event)) {
+ if (event->destroy)
+ event->destroy(event);
+ ret = -EINVAL;
+ }
+ }
+
if (ret)
module_put(pmu->module);