linux-kernel - Re: [PATCH 1/3] perf sched timehist: Mark schedule function in callchains

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Date:   Fri, 25 Nov 2016 20:38:11 -0700
From:   David Ahern <dsahern@...il.com>
To:     Namhyung Kim <namhyung@...nel.org>
Cc:     Arnaldo Carvalho de Melo <acme@...nel.org>,
        Ingo Molnar <mingo@...nel.org>,
        Peter Zijlstra <a.p.zijlstra@...llo.nl>,
        Jiri Olsa <jolsa@...nel.org>,
        LKML <linux-kernel@...r.kernel.org>,
        Stephane Eranian <eranian@...gle.com>,
        Andi Kleen <andi@...stfloor.org>
Subject: Re: [PATCH 1/3] perf sched timehist: Mark schedule function in
 callchains

On 11/23/16 11:30 PM, Namhyung Kim wrote:
> Hi David,
> 
> On Wed, Nov 23, 2016 at 10:13:46PM -0500, David Ahern wrote:
>> On 11/23/16 8:11 PM, Namhyung Kim wrote:
>>> The sched_switch event always captured from the scheduler function.  So
>>> it'd be great omit them from the callchain.  This patch marks the
>>> functions to be omitted by later patch.
>>
>> I had this covered by a symbol filter:
>>
>> https://github.com/dsahern/linux/blob/perf/full-monty-4.1/tools/perf/builtin-sched.c#L3000
>>
>> Not sure what happened over the years but that should still work and
>> allows the user to add more symbols to ignore:
> 
> The symbol filter was removed by commit be39db9f2932 ("perf symbols:
> Remove symbol_filter_t machinery").

That's unfortunate. The exclude list is huge in removing redundant callchains and getting more relevant information on the screen with a stack depth of 5. I'll see what I can cook up with the existing code.