From: Andi Kleen <ak@linux.intel.com>
To: "HATAYAMA, Daisuke" <d.hatayama@jp.fujitsu.com>
Cc: hpa@zytor.com, Don Zickus <dzickus@redhat.com>,
matt@console-pimps.org, peterz@infradead.org, acme@kernel.org,
mingo@redhat.com, paulus@samba.org, tglx@linutronix.de,
x86@kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH v2] perf/x86/intel: ignore CondChgd bit to avoid false NMI handling
Date: Mon, 30 Jun 2014 15:22:24 -0700 [thread overview]
Message-ID: <20140630222224.GH19781@tassilo.jf.intel.com> (raw)
In-Reply-To: <53B12CB3.5050508@jp.fujitsu.com>
>
> I'm also interested in the behaviour of CondChgd bit on Ivy Bridge processors.
The intended meaning of CondChgd is that a hardware debugger has taken over the
PMU. It shouldn't really be set in other circumstances.
I think right now for perf it would be best to just ignore it.
In theory could stop using the PMU, but if some BIOS set it it would
completely disable perf there. So better to just ignore it.
-Andi
--
ak@linux.intel.com -- Speaking for myself only
next prev parent reply other threads:[~2014-06-30 22:22 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-06-13 8:44 [PATCH v2] perf/x86/intel: ignore CondChgd bit to avoid false NMI handling HATAYAMA Daisuke
2014-06-16 15:30 ` Don Zickus
2014-06-30 9:24 ` HATAYAMA, Daisuke
2014-06-30 22:22 ` Andi Kleen [this message]
2014-07-01 8:14 ` Peter Zijlstra
2014-07-01 14:22 ` Don Zickus
2014-07-02 1:07 ` HATAYAMA Daisuke
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=20140630222224.GH19781@tassilo.jf.intel.com \
--to=ak@linux.intel.com \
--cc=acme@kernel.org \
--cc=d.hatayama@jp.fujitsu.com \
--cc=dzickus@redhat.com \
--cc=hpa@zytor.com \
--cc=linux-kernel@vger.kernel.org \
--cc=matt@console-pimps.org \
--cc=mingo@redhat.com \
--cc=paulus@samba.org \
--cc=peterz@infradead.org \
--cc=tglx@linutronix.de \
--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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.