From: Stephane Eranian <eranian@hpl.hp.com>
To: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>,
perfmon2-devel@lists.sourceforge.net, perfmon@napali.hpl.hp.com,
linux-kernel@vger.kernel.org, linux-ia64@vger.kernel.org,
Ingo Molnar <mingo@elte.hu>
Subject: Re: conflict between tickless and perfmon2
Date: Fri, 9 Nov 2007 12:17:11 -0800 [thread overview]
Message-ID: <20071109201711.GA20390@frankl.hpl.hp.com> (raw)
In-Reply-To: <alpine.LRH.0.999.0711091934210.1196@www.tglx.de>
Thomas,
On Fri, Nov 09, 2007 at 07:40:31PM +0100, Thomas Gleixner wrote:
>
> > > It looks like a solution would be to change the implementation of
> > > timeout-based switching to use HR timers instead. Similar to what is
> > > done for ITIMER_REAL and ITIMER_VIRTUAL.
>
> Using a hrtimer is perfrectly fine, I'd say it's preferred over hooks in
> some code which has absoluty no guarantee of being executed periodically
> or even executed at all. OTOH it seems rather stupid to measure stuff
> while the system is idle and doing nothing.
>
I'll start looking into this soon. To answer your point about idle,
this is not because the core is idle that counters do not capture events
related to buses or caches for instance.
--
-Stephane
next prev parent reply other threads:[~2007-11-09 20:24 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2007-11-09 10:44 conflict between tickless and perfmon2 Stephane Eranian
2007-11-09 10:59 ` Peter Zijlstra
2007-11-09 18:40 ` Thomas Gleixner
2007-11-09 20:17 ` Stephane Eranian [this message]
2007-11-14 16:34 ` [perfmon] " Stephane Eranian
2007-11-23 14:28 ` Stephane Eranian
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=20071109201711.GA20390@frankl.hpl.hp.com \
--to=eranian@hpl.hp.com \
--cc=linux-ia64@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=mingo@elte.hu \
--cc=perfmon2-devel@lists.sourceforge.net \
--cc=perfmon@napali.hpl.hp.com \
--cc=peterz@infradead.org \
--cc=tglx@linutronix.de \
/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