From: Peter Zijlstra <peterz@infradead.org>
To: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com>
Cc: Ingo Molnar <mingo@elte.hu>, Mike Galbraith <efault@gmx.de>,
Suresh Siddha <suresh.b.siddha@intel.com>,
Paul Turner <pjt@google.com>,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH v1] sched: steer waking task to empty cfs_rq for better latencies
Date: Tue, 24 Apr 2012 19:09:14 +0200 [thread overview]
Message-ID: <1335287354.28150.209.camel@twins> (raw)
In-Reply-To: <1335286696.28150.206.camel@twins>
On Tue, 2012-04-24 at 18:58 +0200, Peter Zijlstra wrote:
> On Tue, 2012-04-24 at 22:26 +0530, Srivatsa Vaddagiri wrote:
> > Steer a waking task towards a cpu where its cgroup has zero tasks (in
> > order to provide it better sleeper credits and hence reduce its wakeup
> > latency).
>
> That's just vile.. pjt could you post your global vruntime stuff so
> vatsa can have a go at that?
That is, you're playing a deficiency we should fix, not exploit.
Also, you do a second loop over all those cpus right after we've already
iterated them..
furthermore, that 100%+ gain is still way insane, what else is broken?
Did you try those paravirt tlb-flush patches and other such weirdness?
next prev parent reply other threads:[~2012-04-24 17:09 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-04-24 16:56 [PATCH v1] sched: steer waking task to empty cfs_rq for better latencies Srivatsa Vaddagiri
2012-04-24 16:58 ` Peter Zijlstra
2012-04-24 17:07 ` Srivatsa Vaddagiri
2012-04-24 17:12 ` Peter Zijlstra
2012-04-24 17:35 ` Srivatsa Vaddagiri
2012-04-24 18:03 ` Rakib Mullick
2012-04-24 17:09 ` Peter Zijlstra [this message]
2012-04-24 17:26 ` Srivatsa Vaddagiri
2012-05-02 14:01 ` Srivatsa Vaddagiri
2012-05-03 5:43 ` Nikunj A Dadhania
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=1335287354.28150.209.camel@twins \
--to=peterz@infradead.org \
--cc=efault@gmx.de \
--cc=linux-kernel@vger.kernel.org \
--cc=mingo@elte.hu \
--cc=pjt@google.com \
--cc=suresh.b.siddha@intel.com \
--cc=vatsa@linux.vnet.ibm.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