mirror of https://lore.kernel.org/lkml/
 help / color / mirror / Atom feed
From: Peter Zijlstra <peterz@infradead.org>
To: "Liang, Kan" <kan.liang@linux.intel.com>
Cc: x86@kernel.org, eranian@google.com, linux-kernel@vger.kernel.org,
	acme@kernel.org, mark.rutland@arm.com,
	alexander.shishkin@linux.intel.com, jolsa@kernel.org,
	namhyung@kernel.org
Subject: Re: [PATCH 4/5] perf/x86: Change x86_pmu::limit_period signature
Date: Wed, 11 May 2022 22:06:57 +0200	[thread overview]
Message-ID: <20220511200657.GB76023@worktop.programming.kicks-ass.net> (raw)
In-Reply-To: <208c46f9-ca5e-5825-3b4f-a805054315f4@linux.intel.com>

On Wed, May 11, 2022 at 01:47:06PM -0400, Liang, Kan wrote:
> > @@ -1386,19 +1387,14 @@ int x86_perf_event_set_period(struct per
> >   		hwc->last_period = period;
> >   		ret = 1;
> >   	}
> > -	/*
> > -	 * Quirk: certain CPUs dont like it if just 1 hw_event is left:
> > -	 */
> > -	if (unlikely(left < 2))
> > -		left = 2;
> > 
> 
> Is the quirk accidentally deleted?
> We should still need the quirk for certain CPUs.

No, but I did forget to write about it in the Changelog :/

IIRC it was Nehalem that triggered that and that should now be covered
by nhm_limit_period().

Or are you aware of more machines that need this?

Anyway, perhaps this should be its own separate commit.



  reply	other threads:[~2022-05-11 20:07 UTC|newest]

Thread overview: 10+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-05-11 14:20 [PATCH 0/5] perf/x86: Some cleanups Peter Zijlstra
2022-05-11 14:20 ` [PATCH 1/5] perf/x86/amd: Fix AMD BRS period adjustment Peter Zijlstra
2022-05-11 14:20 ` [PATCH 2/5] perf/x86: Add two more x86_pmu methods Peter Zijlstra
2022-05-11 14:20 ` [PATCH 3/5] perf/x86/intel: Move the topdown stuff into the intel driver Peter Zijlstra
2022-05-11 14:20 ` [PATCH 4/5] perf/x86: Change x86_pmu::limit_period signature Peter Zijlstra
2022-05-11 17:47   ` Liang, Kan
2022-05-11 20:06     ` Peter Zijlstra [this message]
2022-05-11 14:20 ` [PATCH 5/5] perf/x86: Add a x86_pmu::limit_period static_call Peter Zijlstra
2022-05-11 15:34 ` [RFC][PATCH 6/5] perf/x86/intel: Remove x86_pmu::set_topdown_event_period Peter Zijlstra
2022-05-11 15:35 ` [RFC][PATCH 7/5] perf/x86/intel: Remove x86_pmu::update_topdown_event Peter Zijlstra

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=20220511200657.GB76023@worktop.programming.kicks-ass.net \
    --to=peterz@infradead.org \
    --cc=acme@kernel.org \
    --cc=alexander.shishkin@linux.intel.com \
    --cc=eranian@google.com \
    --cc=jolsa@kernel.org \
    --cc=kan.liang@linux.intel.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=mark.rutland@arm.com \
    --cc=namhyung@kernel.org \
    --cc=x86@kernel.org \
    /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

Powered by JetHome