aboutsummaryrefslogtreecommitdiff
path: root/kernel
diff options
context:
space:
mode:
authorPeter Zijlstra2016-03-22 22:09:18 +0100
committerIngo Molnar2016-03-31 10:30:41 +0200
commit26657848502b78474a5f17f9ce2ae6dc8d8d6262 (patch)
tree8fe05c327ca5f72701709dd25ff4f90bdce43d03 /kernel
parent07dc900e17a94681877b5797ce62ba97fa170400 (diff)
perf/core: Verify we have a single perf_hw_context PMU
There should (and can) only be a single PMU for perf_hw_context events. This is because of how we schedule events: once a hardware event fails to schedule (the PMU is 'full') we stop trying to add more. The trivial 'fix' would break the Round-Robin scheduling we do. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephane Eranian <eranian@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vince Weaver <vincent.weaver@maine.edu> Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'kernel')
-rw-r--r--kernel/events/core.c9
1 files changed, 9 insertions, 0 deletions
diff --git a/kernel/events/core.c b/kernel/events/core.c
index 52bedc5a5aaa..525d11c59287 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -7693,6 +7693,15 @@ int perf_pmu_register(struct pmu *pmu, const char *name, int type)
}
skip_type:
+ if (pmu->task_ctx_nr == perf_hw_context) {
+ static int hw_context_taken = 0;
+
+ if (WARN_ON_ONCE(hw_context_taken))
+ pmu->task_ctx_nr = perf_invalid_context;
+
+ hw_context_taken = 1;
+ }
+
pmu->pmu_cpu_context = find_pmu_context(pmu->task_ctx_nr);
if (pmu->pmu_cpu_context)
goto got_cpu_context;