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authorJiri Olsa <jolsa@redhat.com>2013-05-01 17:25:44 +0200
committerIngo Molnar <mingo@kernel.org>2013-05-28 08:59:54 +0200
commitab573844e3058eef2788803d373019f8bebead57 (patch)
tree8d040ef2da05caccabce8ccb5f4b168ee3f63216
parentddd40da4ccbabdd2e941837aa987e08dfa4396b4 (diff)
downloadblackbird-op-linux-ab573844e3058eef2788803d373019f8bebead57.tar.gz
blackbird-op-linux-ab573844e3058eef2788803d373019f8bebead57.zip
perf: Fix hw breakpoints overflow period sampling
The hw breakpoint pmu 'add' function is missing the period_left update needed for SW events. The perf HW breakpoint events use the SW events framework to process the overflow, so it needs to be properly initialized in the PMU 'add' method. Signed-off-by: Jiri Olsa <jolsa@redhat.com> Reviewed-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Arnaldo Carvalho de Melo <acme@ghostprotocols.net> Cc: Ingo Molnar <mingo@elte.hu> Cc: Paul Mackerras <paulus@samba.org> Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Vince Weaver <vincent.weaver@maine.edu> Cc: Stephane Eranian <eranian@google.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/1367421944-19082-5-git-send-email-jolsa@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
-rw-r--r--include/linux/perf_event.h2
-rw-r--r--kernel/events/core.c2
-rw-r--r--kernel/events/hw_breakpoint.c5
3 files changed, 8 insertions, 1 deletions
diff --git a/include/linux/perf_event.h b/include/linux/perf_event.h
index f463a46424e2..fa38612d70b6 100644
--- a/include/linux/perf_event.h
+++ b/include/linux/perf_event.h
@@ -743,6 +743,7 @@ extern unsigned int perf_output_skip(struct perf_output_handle *handle,
unsigned int len);
extern int perf_swevent_get_recursion_context(void);
extern void perf_swevent_put_recursion_context(int rctx);
+extern u64 perf_swevent_set_period(struct perf_event *event);
extern void perf_event_enable(struct perf_event *event);
extern void perf_event_disable(struct perf_event *event);
extern int __perf_event_disable(void *info);
@@ -782,6 +783,7 @@ static inline void perf_event_fork(struct task_struct *tsk) { }
static inline void perf_event_init(void) { }
static inline int perf_swevent_get_recursion_context(void) { return -1; }
static inline void perf_swevent_put_recursion_context(int rctx) { }
+static inline u64 perf_swevent_set_period(struct perf_event *event) { return 0; }
static inline void perf_event_enable(struct perf_event *event) { }
static inline void perf_event_disable(struct perf_event *event) { }
static inline int __perf_event_disable(void *info) { return -1; }
diff --git a/kernel/events/core.c b/kernel/events/core.c
index 9dc297faf7c0..e0dcced282e4 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -4961,7 +4961,7 @@ static DEFINE_PER_CPU(struct swevent_htable, swevent_htable);
* sign as trigger.
*/
-static u64 perf_swevent_set_period(struct perf_event *event)
+u64 perf_swevent_set_period(struct perf_event *event)
{
struct hw_perf_event *hwc = &event->hw;
u64 period = hwc->last_period;
diff --git a/kernel/events/hw_breakpoint.c b/kernel/events/hw_breakpoint.c
index a64f8aeb5c1f..966a241e8616 100644
--- a/kernel/events/hw_breakpoint.c
+++ b/kernel/events/hw_breakpoint.c
@@ -612,6 +612,11 @@ static int hw_breakpoint_add(struct perf_event *bp, int flags)
if (!(flags & PERF_EF_START))
bp->hw.state = PERF_HES_STOPPED;
+ if (is_sampling_event(bp)) {
+ bp->hw.last_period = bp->hw.sample_period;
+ perf_swevent_set_period(bp);
+ }
+
return arch_install_hw_breakpoint(bp);
}
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