Re: [PATCH 24/41] perf tools: Add cpu to struct thread

[Adrian Hunter]

On 15/07/2014 5:24 p.m., Arnaldo Carvalho de Melo wrote:
> Em Mon, Jul 14, 2014 at 01:02:48PM +0300, Adrian Hunter escreveu:
> > Tools may wish to track on which cpu a thread
> > is running.  Add 'cpu' to struct thread for
> > that purpose.
> >
> > This will be used to determine the cpu when
> > decoding a per-thread Instruction Trace.
>
> Humm, is this the last cpu we got some event telling the cpu was running
> on? Continuing looking at the patches...

Yes.  Intel PT decoding uses sched_switch events to determine which
task is running on which cpu.  The Intel PT data comes straight
from the hardware which doesn't know about linux threads.

> - Arnaldo
>
> > Signed-off-by: Adrian Hunter <adrian.hunter@xxxxxxxxx>
> > ---
> >   tools/perf/util/thread.c | 1 +
> >   tools/perf/util/thread.h | 1 +
> >   2 files changed, 2 insertions(+)
> >
> > diff --git a/tools/perf/util/thread.c b/tools/perf/util/thread.c
> > index b9a3ee4..2f8c0c1 100644
> > --- a/tools/perf/util/thread.c
> > +++ b/tools/perf/util/thread.c
> > @@ -69,6 +69,7 @@ struct thread *thread__new(pid_t pid, pid_t tid)
> >   		thread->pid_ = pid;
> >   		thread->tid = tid;
> >   		thread->ppid = -1;
> > +		thread->cpu = -1;
> >   		INIT_LIST_HEAD(&thread->comm_list);
> >
> >   		comm_str = malloc(32);
> > diff --git a/tools/perf/util/thread.h b/tools/perf/util/thread.h
> > index b4269af..e4920ff 100644
> > --- a/tools/perf/util/thread.h
> > +++ b/tools/perf/util/thread.h
> > @@ -17,6 +17,7 @@ struct thread {
> >   	pid_t			pid_; /* Not all tools update this */
> >   	pid_t			tid;
> >   	pid_t			ppid;
> > +	int			cpu;
> >   	char			shortname[3];
> >   	bool			comm_set;
> >   	bool			dead; /* if set thread has exited */
> > --
> > 1.8.3.2
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