linux-kernel - Re: [PATCH 2/9] perf tools: Count periods of filtered entries separately

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Date:	Tue, 18 Mar 2014 23:11:10 +0900
From:	Namhyung Kim <namhyung@...nel.org>
To:	Arnaldo Carvalho de Melo <acme@...stprotocols.net>
Cc:	Peter Zijlstra <a.p.zijlstra@...llo.nl>,
	Ingo Molnar <mingo@...nel.org>,
	Paul Mackerras <paulus@...ba.org>,
	Namhyung Kim <namhyung.kim@....com>,
	LKML <linux-kernel@...r.kernel.org>,
	Jiri Olsa <jolsa@...hat.com>, David Ahern <dsahern@...il.com>,
	Andi Kleen <andi@...stfloor.org>
Subject: Re: [PATCH 2/9] perf tools: Count periods of filtered entries separately

On Tue, Mar 18, 2014 at 10:18 PM, Arnaldo Carvalho de Melo
<acme@...stprotocols.net> wrote:
> Em Tue, Mar 18, 2014 at 10:15:18AM -0300, Arnaldo Carvalho de Melo escreveu:
>> Em Tue, Mar 18, 2014 at 01:19:07PM +0900, Namhyung Kim escreveu:
>> > On Tue, Mar 18, 2014 at 5:08 AM, Arnaldo Carvalho de Melo
>> > <acme@...stprotocols.net> wrote:
>> > > Em Mon, Mar 10, 2014 at 04:43:53PM +0900, Namhyung Kim escreveu:
>> > >> @@ -749,9 +750,6 @@ int perf_event__preprocess_sample(const union perf_event *event,
>> > >>       if (thread == NULL)
>> > >>               return -1;
>> > >>
>> > >> -     if (thread__is_filtered(thread))
>> > >> -             goto out_filtered;
>> > >> -
>> > >
>> > > What was the intent of moving this test from here...
>> > >
>> > >>       dump_printf(" ... thread: %s:%d\n", thread__comm_str(thread), thread->tid);
>> > >>       /*
>> > >>        * Have we already created the kernel maps for this machine?
>> > >> @@ -766,6 +764,10 @@ int perf_event__preprocess_sample(const union perf_event *event,
>> > >>
>> > >>       thread__find_addr_map(thread, machine, cpumode, MAP__FUNCTION,
>> > >>                             sample->ip, al);
>> > >> +
>> > >> +     if (thread__is_filtered(thread))
>> > >> +             al->filtered |= (1 << HIST_FILTER__THREAD);
>> > >> +
>> > >
>> > > ... to here? At first I thought it was because thread__is_filtered()
>> > > would check something that thread__find_addr_map() was doing, but no,
>> > > its invariant, we can do it here or at the original site, so I'm keeping
>> > > it there, ok?
>> >
>> > It's because thread__find_addr_map() clears al->filtered, so filtering
>> > with -d option won't work.  Maybe we can move initialization of the
>> > al->filtered upto this function.
>>
>> So this is a separate patch with this explanation, I'll add it to the
>> series, thanks for the explanation!
>
> Humm, it really needs to be folded into the patch that does all the
> tests, as before we were just stopping the filters early and thus no
> problem existed, its only now that we apply all the filters that we need
> to be careful in knowing that thread__find_addr_map() is when
> al->filtered gets initialized to zero, right?

Right. :)

Thanks,
Namhyung
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