public inbox for linux-kernel@vger.kernel.org
 help / color / mirror / Atom feed
From: Andi Kleen <ak@linux.intel.com>
To: "Liang, Kan" <kan.liang@intel.com>
Cc: Vince Weaver <vincent.weaver@maine.edu>,
	Peter Zijlstra <peterz@infradead.org>,
	"Odzioba, Lukasz" <lukasz.odzioba@intel.com>,
	Stephane Eranian <eranian@google.com>,
	"mingo@redhat.com" <mingo@redhat.com>,
	LKML <linux-kernel@vger.kernel.org>,
	Alexander Shishkin <alexander.shishkin@linux.intel.com>
Subject: Re: [PATCH] perf/x86: fix event counter update issue
Date: Wed, 22 Feb 2017 11:18:48 -0800	[thread overview]
Message-ID: <20170222191848.GE1712@tassilo.jf.intel.com> (raw)
In-Reply-To: <37D7C6CF3E00A74B8858931C1DB2F077536A9963@SHSMSX103.ccr.corp.intel.com>

> No. It related to the counter width. The number of bits we can use should be
> 1 bit less than the total width. Otherwise, there will be problem.
> For big cores such as haswell, broadwell, skylake, the counter width is 48 bit.
> So we can only use 47 bits.
> For Silvermont and KNL, the counter width is only 32 bit I think. So we can only
> use 31 bits.

It is 40 bits on these cores, so 39bits.

-Andi

  reply	other threads:[~2017-02-22 19:19 UTC|newest]

Thread overview: 27+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-11-28 19:26 [PATCH] perf/x86: fix event counter update issue kan.liang
2016-11-28 19:41 ` Stephane Eranian
2016-11-28 19:59   ` Liang, Kan
2016-11-28 20:18     ` Stephane Eranian
2016-11-28 20:23       ` Liang, Kan
2016-11-29  9:25 ` Peter Zijlstra
2016-11-29 14:46   ` Liang, Kan
2016-11-29 16:58     ` Peter Zijlstra
2016-11-29 17:06       ` Liang, Kan
2016-11-29 17:17         ` Peter Zijlstra
2016-11-29 17:20   ` Stephane Eranian
2016-11-29 17:30     ` Peter Zijlstra
2016-11-29 18:11       ` Stephane Eranian
2016-11-29 18:37       ` Andi Kleen
2016-11-29 19:07       ` Liang, Kan
2016-11-29 19:32         ` Peter Zijlstra
2016-11-29 20:33           ` Liang, Kan
2016-11-29 20:37             ` Stephane Eranian
2016-12-02 12:58             ` Odzioba, Lukasz
2016-12-05 10:25               ` Peter Zijlstra
2016-12-05 11:21                 ` Odzioba, Lukasz
2017-02-22 14:49                 ` Vince Weaver
2017-02-22 15:28                   ` Liang, Kan
2017-02-22 19:18                     ` Andi Kleen [this message]
2017-02-23 15:07                     ` Vince Weaver
2017-02-23 16:14                       ` Liang, Kan
2016-11-29 19:08     ` Odzioba, Lukasz

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=20170222191848.GE1712@tassilo.jf.intel.com \
    --to=ak@linux.intel.com \
    --cc=alexander.shishkin@linux.intel.com \
    --cc=eranian@google.com \
    --cc=kan.liang@intel.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=lukasz.odzioba@intel.com \
    --cc=mingo@redhat.com \
    --cc=peterz@infradead.org \
    --cc=vincent.weaver@maine.edu \
    /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