lkml.org 
[lkml]   [2014]   [Jun]   [5]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
Date
From
Subject[tip:perf/core] perf: Disable sampled events if no PMU interrupt
Commit-ID:  53b25335dd60981ad608da7890420898a34469a6
Gitweb: http://git.kernel.org/tip/53b25335dd60981ad608da7890420898a34469a6
Author: Vince Weaver <vincent.weaver@maine.edu>
AuthorDate: Fri, 16 May 2014 17:12:12 -0400
Committer: Ingo Molnar <mingo@kernel.org>
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@maine.edu>
Acked-by: Will Deacon <will.deacon@arm.com>
[peterz: rename to PERF_PMU_CAP_* and moved the pmu::capabilities word into a hole]
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: http://lkml.kernel.org/r/alpine.DEB.2.10.1405161708060.11099@vincent-weaver-1.umelst.maine.edu
Signed-off-by: Ingo Molnar <mingo@kernel.org>

Signed-off-by: Ingo Molnar <mingo@kernel.org>
---
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);

/*

\
 
 \ /
  Last update: 2014-06-05 20:21    [W:0.786 / U:0.044 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site