From: Jason Low <jason.low2@hp.com>
To: Peter Zijlstra <peterz@infradead.org>
Cc: Ingo Molnar <mingo@kernel.org>,
linux-kernel@vger.kernel.org,
Frederic Weisbecker <fweisbec@gmail.com>,
Oleg Nesterov <oleg@redhat.com>,
"Paul E. McKenney" <paulmck@linux.vnet.ibm.com>,
Davidlohr Bueso <dave@stgolabs.net>,
Mike Galbraith <umgwanakikbuti@gmail.com>,
terry.rudd@hp.com, Rik van Riel <riel@redhat.com>,
Waiman Long <Waiman.Long@hp.com>,
Scott J Norton <scott.norton@hp.com>,
jason.low2@hp.com
Subject: Re: [RFC PATCH] timer: Improve itimers scalability
Date: Wed, 05 Aug 2015 12:44:41 -0700 [thread overview]
Message-ID: <1438803881.4833.34.camel@j-VirtualBox> (raw)
In-Reply-To: <20150805093719.GV25159@twins.programming.kicks-ass.net>
On Wed, 2015-08-05 at 11:37 +0200, Peter Zijlstra wrote:
> On Tue, Aug 04, 2015 at 05:29:44PM -0700, Jason Low wrote:
>
> > @@ -1137,6 +1148,13 @@ static inline int fastpath_timer_check(struct task_struct *tsk)
> > if (READ_ONCE(sig->cputimer.running)) {
>
> Maybe make that:
>
> if (READ_ONCE(sig->cputimer.running) &&
> !READ_ONCE(sig->cputimer.is_checking_timer)) {
Yes, I think it would be better if the check is done here.
And perhaps the comment can be modified to:
/*
* Check if thread group timers expired. This is skipped if the cputimer
* is not running or if another thread in the group is already checking
* for thread group cputimers.
*/
next prev parent reply other threads:[~2015-08-05 19:50 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-08-05 0:29 [RFC PATCH] timer: Improve itimers scalability Jason Low
2015-08-05 9:24 ` Peter Zijlstra
2015-08-05 9:37 ` Peter Zijlstra
2015-08-05 19:44 ` Jason Low [this message]
2015-08-06 14:18 ` Oleg Nesterov
2015-08-06 18:21 ` Jason Low
2015-08-07 12:01 ` Oleg Nesterov
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=1438803881.4833.34.camel@j-VirtualBox \
--to=jason.low2@hp.com \
--cc=Waiman.Long@hp.com \
--cc=dave@stgolabs.net \
--cc=fweisbec@gmail.com \
--cc=linux-kernel@vger.kernel.org \
--cc=mingo@kernel.org \
--cc=oleg@redhat.com \
--cc=paulmck@linux.vnet.ibm.com \
--cc=peterz@infradead.org \
--cc=riel@redhat.com \
--cc=scott.norton@hp.com \
--cc=terry.rudd@hp.com \
--cc=umgwanakikbuti@gmail.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 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.