mirror of https://lore.kernel.org/lkml/
 help / color / mirror / Atom feed
From: Peter Zijlstra <peterz@infradead.org>
To: Dapeng Mi <dapeng1.mi@linux.intel.com>
Cc: Ingo Molnar <mingo@redhat.com>,
	Arnaldo Carvalho de Melo <acme@kernel.org>,
	Namhyung Kim <namhyung@kernel.org>,
	Ian Rogers <irogers@google.com>,
	Adrian Hunter <adrian.hunter@intel.com>,
	Alexander Shishkin <alexander.shishkin@linux.intel.com>,
	Andi Kleen <ak@linux.intel.com>,
	Eranian Stephane <eranian@google.com>,
	linux-kernel@vger.kernel.org, linux-perf-users@vger.kernel.org,
	Dapeng Mi <dapeng1.mi@intel.com>, Zide Chen <zide.chen@intel.com>,
	Falcon Thomas <thomas.falcon@intel.com>,
	Xudong Hao <xudong.hao@intel.com>
Subject: Re: [PATCH] perf: Fix 0 count issue of cpu-clock
Date: Tue, 18 Nov 2025 11:50:06 +0100	[thread overview]
Message-ID: <20251118105006.GO3245006@noisy.programming.kicks-ass.net> (raw)
In-Reply-To: <20251112080526.3971392-1-dapeng1.mi@linux.intel.com>

On Wed, Nov 12, 2025 at 04:05:26PM +0800, Dapeng Mi wrote:
> Currently cpu-clock event always returns 0 count, e.g.,
> 
> perf stat -e cpu-clock -- sleep 1
> 
>  Performance counter stats for 'sleep 1':
>                  0      cpu-clock                        #    0.000 CPUs utilized
>        1.002308394 seconds time elapsed
> 
> The root cause is the commit 'bc4394e5e79c ("perf: Fix the throttle
>  error of some clock events")' adds PERF_EF_UPDATE flag check before
> calling cpu_clock_event_update() to update the count, however the
> PERF_EF_UPDATE flag is never set when the cpu-clock event is stopped in
> counting mode (pmu->dev() -> cpu_clock_event_del() ->
> cpu_clock_event_stop()). This leads to the cpu-clock event count is
> never updated.
> 
> To fix this issue, force to set PERF_EF_UPDATE flag for cpu-clock event
> just like what task-clock does. Besides, or flags with PERF_EF_UPDATE
> for task-clock although currently the flags argument would always be 0.
> 
> Fixes: bc4394e5e79c ("perf: Fix the throttle error of some clock events")
> Signed-off-by: Dapeng Mi <dapeng1.mi@linux.intel.com>
> ---

So I'm forever struggling to find what tree a particular commit is in,
but afaict the above fingered commit is already in Linus' tree and so
this should go to perf/urgent, right?

  parent reply	other threads:[~2025-11-18 10:50 UTC|newest]

Thread overview: 12+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2025-11-12  8:05 Dapeng Mi
2025-11-12 16:42 ` Ian Rogers
2025-11-17 17:04   ` Ian Rogers
2025-11-18  1:43 ` Namhyung Kim
2025-11-18 10:50 ` Peter Zijlstra [this message]
2025-11-18 11:03 ` Peter Zijlstra
2025-11-18 11:04   ` Peter Zijlstra
2025-11-18 11:22     ` Mi, Dapeng
2025-11-18 11:24       ` Peter Zijlstra
2025-12-05 23:44         ` Ian Rogers
2025-12-08  5:16           ` Mi, Dapeng
2025-11-20  9:47 ` [tip: perf/urgent] " tip-bot2 for Dapeng Mi

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20251118105006.GO3245006@noisy.programming.kicks-ass.net \
    --to=peterz@infradead.org \
    --cc=acme@kernel.org \
    --cc=adrian.hunter@intel.com \
    --cc=ak@linux.intel.com \
    --cc=alexander.shishkin@linux.intel.com \
    --cc=dapeng1.mi@intel.com \
    --cc=dapeng1.mi@linux.intel.com \
    --cc=eranian@google.com \
    --cc=irogers@google.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-perf-users@vger.kernel.org \
    --cc=mingo@redhat.com \
    --cc=namhyung@kernel.org \
    --cc=thomas.falcon@intel.com \
    --cc=xudong.hao@intel.com \
    --cc=zide.chen@intel.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox

all inboxes | Powered by JetHome®