2012/9/18 Andrew Vagin <[email protected]>:
> You may want to know where and how long a task is sleeping. A callchain
> may be found in sched_switch and a time slice in stat_iowait, so I add
> handler in perf inject for merging this events.
>
> My code saves sched_switch event for each process and when it meets
> stat_iowait, it reports the sched_switch event, because this event
> contains a correct callchain. By another words it replaces all
> stat_iowait events on proper sched_switch events.
>
> v2: - remove the global variable "session"
> - hadle errors from malloc()
>
> v3: - use sample->tid instead of sample->pid for merging events.
>
> Frederic Weisbecker noticed that this code works only in a root pidns.
> It's true, because a pid from trace content is not pid-namespace safe
> and currently no way to get this pid in a current pidns. This problem
> is more general, so I don't think that it should be solved in this series.
>
> Cc: Arnaldo Carvalho de Melo <[email protected]>
I'm ok with it, so Acked-by: Frederic Weisbecker <[email protected]>
I just have some suggestions below.
> Cc: Peter Zijlstra <[email protected]>
> Cc: Paul Mackerras <[email protected]>,
> Cc: Ingo Molnar <[email protected]
> Cc: Andi Kleen <[email protected]>
> Cc: David Ahern <[email protected]>
> Signed-off-by: Andrew Vagin <[email protected]>
> ---
> tools/perf/Documentation/perf-inject.txt | 4 ++
> tools/perf/builtin-inject.c | 86 ++++++++++++++++++++++++++++++
> 2 files changed, 90 insertions(+), 0 deletions(-)
>
> diff --git a/tools/perf/Documentation/perf-inject.txt b/tools/perf/Documentation/perf-inject.txt
> index 6be2101..c04e0c6 100644
> --- a/tools/perf/Documentation/perf-inject.txt
> +++ b/tools/perf/Documentation/perf-inject.txt
> @@ -35,6 +35,10 @@ OPTIONS
> -o::
> --output=::
> Output file name. (default: stdout)
> +-s::
> +--sched-stat::
> + Merge sched_stat and sched_switch for getting events where and how long
> + tasks slept.
Please provide some more explanations here. I fear it's not very clear
for the user. May be tell about the fact it results in sched_switch
events weighted with the time slept.
[...]
> +static int perf_event__sched_stat(struct perf_tool *tool,
> + union perf_event *event,
> + struct perf_sample *sample,
> + struct perf_evsel *evsel,
> + struct machine *machine)
> +{
> + const char *evname = NULL;
> + uint32_t size;
> + struct event_entry *ent;
> + union perf_event *event_sw = NULL;
> + struct perf_sample sample_sw;
> + int sched_process_exit;
> +
> + size = event->header.size;
> +
> + evname = evsel->tp_format->name;
> +
> + sched_process_exit = !strcmp(evname, "sched_process_exit");
> +
> + if (!strcmp(evname, "sched_switch") || sched_process_exit) {
> + list_for_each_entry(ent, &samples, node)
> + if (sample->tid == ent->tid)
Make sure you have PERF_SAMPLE_TID.
Thanks.
On Tue, Oct 16, 2012 at 01:27:13AM +0V400, Frederic Weisbecker wrote:
> 2012/9/18 Andrew Vagin <[email protected]>:
> > You may want to know where and how long a task is sleeping. A callchain
> > may be found in sched_switch and a time slice in stat_iowait, so I add
> > handler in perf inject for merging this events.
> >
...
>
> I'm ok with it, so Acked-by: Frederic Weisbecker <[email protected]>
>
> I just have some suggestions below.
Hello Arnaldo,
The fixed version of this patch is attached to this message.
All other patches of the series are in the branch "sleep" of your tree.
Could you move this series in a main branch for including to the
mainstream kernel?
Thanks.
>
> > Cc: Peter Zijlstra <[email protected]>
> > Cc: Paul Mackerras <[email protected]>,
> > Cc: Ingo Molnar <[email protected]
> > Cc: Andi Kleen <[email protected]>
> > Cc: David Ahern <[email protected]>
> > Signed-off-by: Andrew Vagin <[email protected]>
> > ---
> > tools/perf/Documentation/perf-inject.txt | 4 ++
> > tools/perf/builtin-inject.c | 86 ++++++++++++++++++++++++++++++
> > 2 files changed, 90 insertions(+), 0 deletions(-)
> >
> > diff --git a/tools/perf/Documentation/perf-inject.txt b/tools/perf/Documentation/perf-inject.txt
> > index 6be2101..c04e0c6 100644
> > --- a/tools/perf/Documentation/perf-inject.txt
> > +++ b/tools/perf/Documentation/perf-inject.txt
> > @@ -35,6 +35,10 @@ OPTIONS
> > -o::
> > --output=::
> > Output file name. (default: stdout)
> > +-s::
> > +--sched-stat::
> > + Merge sched_stat and sched_switch for getting events where and how long
> > + tasks slept.
>
> Please provide some more explanations here. I fear it's not very clear
> for the user. May be tell about the fact it results in sched_switch
> events weighted with the time slept.
>
> [...]
> > +static int perf_event__sched_stat(struct perf_tool *tool,
> > + union perf_event *event,
> > + struct perf_sample *sample,
> > + struct perf_evsel *evsel,
> > + struct machine *machine)
> > +{
> > + const char *evname = NULL;
> > + uint32_t size;
> > + struct event_entry *ent;
> > + union perf_event *event_sw = NULL;
> > + struct perf_sample sample_sw;
> > + int sched_process_exit;
> > +
> > + size = event->header.size;
> > +
> > + evname = evsel->tp_format->name;
> > +
> > + sched_process_exit = !strcmp(evname, "sched_process_exit");
> > +
> > + if (!strcmp(evname, "sched_switch") || sched_process_exit) {
> > + list_for_each_entry(ent, &samples, node)
> > + if (sample->tid == ent->tid)
>
> Make sure you have PERF_SAMPLE_TID.
>
> Thanks.