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From: Andi Kleen <ak@linux.intel.com>
To: Namhyung Kim <namhyung@kernel.org>
Cc: Ian Rogers <irogers@google.com>,
	linux-perf-users@vger.kernel.org, acme@kernel.org
Subject: Re: Perf stat regression from d15480a3d67
Date: Fri, 23 Jun 2023 10:04:57 -0700	[thread overview]
Message-ID: <ZJXQuWyDKbL8Psre@tassilo> (raw)
In-Reply-To: <CAM9d7cj1XXpuaPss7qa7eSD8LJCQZ1KorviOxxnt2Hpk_J3ugQ@mail.gmail.com>

> > Okay so the skipping can just be removed?
> 
> The existing use case was system-wide --per-thread mode.
> It would generate too much noise without it.

Hmm I guess we could make it default for per thread mode, but add an
option to turn it on again if it's needed

(my tool currently doesn't do per thread, but I can could imagine
adding that at some point)

> > > Didn't you say you only have problems in uncore events?
> >
> > For this test case I only hit it with the uncore, but I would have a general
> > problem for any event if it was hidden.
> 
> stat-display.c::should_skip_zero_counter() specifically checks
> uncore PMU events, so I don't think core events have problems.
> 
> Also it only skips when aggregation id doesn't match, which means
> the (default) global aggregation mode should not skip any uncore
> events.
> 
> Can you please help me to find a minimal repro?

I'll run delta[1] over it later today.
But you may need a SKX.

-Andi

[1] https://github.com/dsw/delta

  reply	other threads:[~2023-06-23 17:05 UTC|newest]

Thread overview: 15+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-06-22  1:39 Perf stat regression from d15480a3d67 Andi Kleen
2023-06-22  6:10 ` Ian Rogers
2023-06-22  9:20   ` Andi Kleen
2023-06-22 13:41     ` Ian Rogers
2023-06-22 19:09     ` Namhyung Kim
2023-06-22 20:15       ` Andi Kleen
2023-06-23  0:08         ` Namhyung Kim
2023-06-23 17:04           ` Andi Kleen [this message]
2023-06-23 18:35           ` Andi Kleen
2023-06-23 18:53             ` Ian Rogers
2023-06-23 23:04               ` Namhyung Kim
2023-06-24 17:59                 ` Andi Kleen
2023-06-26  5:33                   ` Ian Rogers
2023-06-26 23:09                   ` Namhyung Kim
2023-06-26 23:52                     ` Andi Kleen

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