From: Peter Zijlstra <a.p.zijlstra@chello.nl>
To: Yong Wang <yong.y.wang@linux.intel.com>
Cc: eranian@gmail.com, "Wang, Yong Y" <yong.y.wang@intel.com>,
Ingo Molnar <mingo@elte.hu>, LKML <linux-kernel@vger.kernel.org>,
Paul Mackerras <paulus@samba.org>,
Andi Kleen <andi@firstfloor.org>
Subject: Re: perf_counter Atom patch
Date: Tue, 23 Jun 2009 11:10:05 +0200 [thread overview]
Message-ID: <1245748205.19816.1550.camel@twins> (raw)
In-Reply-To: <20090623083420.GB23534@ywang-moblin2.bj.intel.com>
On Tue, 2009-06-23 at 16:34 +0800, Yong Wang wrote:
> > you could simply consider having 0 fixed counters and everything else would work
> > as expected. But there is a catch, unfortunately, in that there is erratum AE49
> > which says that there is only one enable bit to control the two generic counters
> > on Core Duo/Solo.
Ah, that's similar to P6 like machines. The P6 docs say that to disable
a counter you should simply write all zeros (except the EN bit for ctr0)
to the control register (IIRC).
I suppose we could do something similar on these errata cores, make
x86_pmu_disable_counter() write ARCH_PERFMON_EVENTSEL0_ENABLE instead.
Would that work?
next prev parent reply other threads:[~2009-06-23 9:10 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-06-22 20:26 perf_counter Atom patch stephane eranian
2009-06-23 3:38 ` Wang, Yong Y
2009-06-23 7:45 ` stephane eranian
2009-06-23 7:59 ` Yong Wang
2009-06-23 8:27 ` stephane eranian
2009-06-23 8:34 ` Yong Wang
2009-06-23 9:10 ` Peter Zijlstra [this message]
2009-06-23 9:40 ` stephane eranian
2009-06-23 8:40 ` stephane eranian
2009-06-23 8:53 ` Yong Wang
2009-06-23 9:19 ` stephane eranian
2009-06-23 9:47 ` Ingo Molnar
2009-06-24 2:19 ` Yong Wang
2009-06-24 8:52 ` Ingo Molnar
2009-06-25 10:39 ` stephane eranian
2009-06-23 5:59 ` Wang, Yong Y
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=1245748205.19816.1550.camel@twins \
--to=a.p.zijlstra@chello.nl \
--cc=andi@firstfloor.org \
--cc=eranian@gmail.com \
--cc=linux-kernel@vger.kernel.org \
--cc=mingo@elte.hu \
--cc=paulus@samba.org \
--cc=yong.y.wang@intel.com \
--cc=yong.y.wang@linux.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