Commit-ID: 53b25335dd60981ad608da7890420898a34469a6
Gitweb: http://git.kernel.org/tip/53b25335dd60981ad608da7890420898a34469a6
Author: Vince Weaver <vincent.weaver@xxxxxxxxx>
AuthorDate: Fri, 16 May 2014 17:12:12 -0400
Committer: Ingo Molnar <mingo@xxxxxxxxxx>
CommitDate: Thu, 5 Jun 2014 12:29:55 +0200
perf: Disable sampled events if no PMU interrupt
Add common code to generate -ENOTSUPP at event creation time if an
architecture attempts to create a sampled event and
PERF_PMU_NO_INTERRUPT is set.
This adds a new pmu->capabilities flag. Initially we only support
PERF_PMU_NO_INTERRUPT (to indicate a PMU has no support for generating
hardware interrupts) but there are other capabilities that can be
added later.
Signed-off-by: Vince Weaver <vincent.weaver@xxxxxxxxx>
Acked-by: Will Deacon <will.deacon@xxxxxxx>
[peterz: rename to PERF_PMU_CAP_* and moved the pmu::capabilities word into a hole]
Signed-off-by: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Link: http://lkml.kernel.org/r/alpine.DEB.2.10.1405161708060.11099@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx>
Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx>
---
include/linux/perf_event.h | 10 ++++++++++
kernel/events/core.c | 7 +++++++
2 files changed, 17 insertions(+)
diff --git a/include/linux/perf_event.h b/include/linux/perf_event.h
index af6dcf1..267c8f3 100644
--- a/include/linux/perf_event.h
+++ b/include/linux/perf_event.h
@@ -167,6 +167,11 @@ struct perf_event;
#define PERF_EVENT_TXN 0x1
/**
+ * pmu::capabilities flags
+ */
+#define PERF_PMU_CAP_NO_INTERRUPT 0x01
+
+/**
* struct pmu - generic performance monitoring unit
*/
struct pmu {
@@ -178,6 +183,11 @@ struct pmu {
const char *name;
int type;
+ /*
+ * various common per-pmu feature flags
+ */
+ int capabilities;
+
int * __percpu pmu_disable_count;
struct perf_cpu_context * __percpu pmu_cpu_context;
int task_ctx_nr;
diff --git a/kernel/events/core.c b/kernel/events/core.c
index a62d142..e9ef0c6 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -7120,6 +7120,13 @@ SYSCALL_DEFINE5(perf_event_open,
}
}
+ if (is_sampling_event(event)) {
+ if (event->pmu->capabilities & PERF_PMU_CAP_NO_INTERRUPT) {
+ err = -ENOTSUPP;
+ goto err_alloc;
+ }
+ }
+
account_event(event);
/*
--
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