On Mon, Jan 05, 2015 at 03:23:38PM -0800, Shaohua Li wrote:
> Good, it works. But the timestamp (.time_running and friends) only gets
> updated for real hardware event between context switches. For software
> event, the timestamp is initialized once, then never updated. If I use
> it to get time, I actually get CLOCK_MONOTONIC. Hardware events work
> well here, but depending on hardware event is too tricky, which I'd like
> to avoid.
Hmm, that's an unfortunate difference in behaviour, does something like
the below cure that for you?
---
kernel/events/core.c | 6 ++++++
1 file changed, 6 insertions(+)
diff --git a/kernel/events/core.c b/kernel/events/core.c
index 4c1ee7f2bebc..0feb4e039359 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -5965,11 +5965,13 @@ static void perf_swevent_del(struct perf_event *event,
int flags)
static void perf_swevent_start(struct perf_event *event, int flags)
{
event->hw.state = 0;
+ perf_event_update_userpage(event);
}
static void perf_swevent_stop(struct perf_event *event, int flags)
{
event->hw.state = PERF_HES_STOPPED;
+ perf_event_update_userpage(event);
}
/* Deref the hlist from the update side */
@@ -6410,12 +6412,14 @@ static void cpu_clock_event_start(struct perf_event
*event, int flags)
{
local64_set(&event->hw.prev_count, local_clock());
perf_swevent_start_hrtimer(event);
+ perf_event_update_userpage(event);
}
static void cpu_clock_event_stop(struct perf_event *event, int flags)
{
perf_swevent_cancel_hrtimer(event);
cpu_clock_event_update(event);
+ perf_event_update_userpage(event);
}
static int cpu_clock_event_add(struct perf_event *event, int flags)
@@ -6484,12 +6488,14 @@ static void task_clock_event_start(struct perf_event
*event, int flags)
{
local64_set(&event->hw.prev_count, event->ctx->time);
perf_swevent_start_hrtimer(event);
+ perf_event_update_userpage(event);
}
static void task_clock_event_stop(struct perf_event *event, int flags)
{
perf_swevent_cancel_hrtimer(event);
task_clock_event_update(event, event->ctx->time);
+ perf_event_update_userpage(event);
}
static int task_clock_event_add(struct perf_event *event, int flags)
--
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