From: Peter Zijlstra <peterz@infradead.org>
To: Ingo Molnar <mingo@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>,
Waiman Long <Waiman.Long@hp.com>, Ingo Molnar <mingo@elte.hu>,
Andrew Morton <akpm@linux-foundation.org>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
Rik van Riel <riel@redhat.com>,
Peter Hurley <peter@hurleysoftware.com>,
Davidlohr Bueso <davidlohr.bueso@hp.com>,
Alex Shi <alex.shi@intel.com>,
Tim Chen <tim.c.chen@linux.intel.com>,
Andrea Arcangeli <aarcange@redhat.com>,
Matthew R Wilcox <matthew.r.wilcox@intel.com>,
Dave Hansen <dave.hansen@intel.com>,
Michel Lespinasse <walken@google.com>,
Andi Kleen <andi@firstfloor.org>,
"Chandramouleeswaran, Aswin" <aswin@hp.com>,
"Norton, Scott J" <scott.norton@hp.com>
Subject: Re: [PATCH] rwsem: reduce spinlock contention in wakeup code path
Date: Tue, 1 Oct 2013 10:10:11 +0200 [thread overview]
Message-ID: <20131001081011.GM3081@twins.programming.kicks-ass.net> (raw)
In-Reply-To: <20131001074802.GB20889@gmail.com>
On Tue, Oct 01, 2013 at 09:48:02AM +0200, Ingo Molnar wrote:
>
> * Peter Zijlstra <peterz@infradead.org> wrote:
>
> > On Sat, Sep 28, 2013 at 11:55:26AM -0700, Linus Torvalds wrote:
> > > So if the primary reason for this is really just that f*cking anon_vma
> > > lock, then I would seriously suggest:
> >
> > I would still like to see the rwsem patches merged; even if we end up
> > going back to a spin style anon_vma lock.
> >
> > There's been various reports in the past about how programs are
> > significantly faster if they wrap their mmap() calls in a pthread_mutex.
> > And this was purely down to the fact that rwsem writer-writer contention
> > blows chunks.
>
> That's about the mm->mmap_sem rwsem, right?
Yep.
> That impact would have to be measured carefully, and not just for
> workloads where we know that better contention logic helps, but other MM
> workloads that are hitting hard on mmap_sem.
Sure.
next prev parent reply other threads:[~2013-10-01 8:10 UTC|newest]
Thread overview: 55+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-09-27 19:00 Waiman Long
2013-09-27 19:28 ` Linus Torvalds
2013-09-27 19:39 ` Davidlohr Bueso
2013-09-27 21:49 ` Tim Chen
2013-09-28 6:45 ` Ingo Molnar
2013-09-28 7:41 ` Ingo Molnar
2013-09-28 18:55 ` Linus Torvalds
2013-09-28 19:13 ` Andi Kleen
2013-09-28 19:22 ` Linus Torvalds
2013-09-28 19:21 ` Ingo Molnar
2013-09-28 19:33 ` Linus Torvalds
2013-09-28 19:39 ` Ingo Molnar
2013-09-30 10:44 ` Peter Zijlstra
2013-09-30 16:13 ` Linus Torvalds
2013-09-30 16:41 ` Peter Zijlstra
2013-10-01 7:28 ` Ingo Molnar
2013-10-01 8:09 ` Peter Zijlstra
2013-10-01 8:25 ` Ingo Molnar
2013-09-30 15:58 ` Waiman Long
2013-10-01 7:33 ` Ingo Molnar
2013-10-01 20:03 ` Waiman Long
2013-09-28 19:37 ` [PATCH] anon_vmas: Convert the rwsem to an rwlock_t Ingo Molnar
2013-09-28 19:43 ` Linus Torvalds
2013-09-28 19:46 ` Ingo Molnar
2013-09-28 19:52 ` [PATCH, v2] " Ingo Molnar
2013-09-30 11:00 ` Peter Zijlstra
2013-09-30 11:44 ` Peter Zijlstra
2013-09-30 17:03 ` Andrew Morton
2013-09-30 17:25 ` Linus Torvalds
2013-09-30 17:10 ` Tim Chen
2013-09-30 18:14 ` Peter Zijlstra
2013-09-30 19:23 ` Tim Chen
2013-09-30 19:35 ` Waiman Long
2013-09-30 19:47 ` Tim Chen
2013-09-30 22:03 ` Tim Chen
2013-10-01 2:41 ` Waiman Long
2013-09-30 8:52 ` [PATCH] " Andrea Arcangeli
2013-09-30 14:40 ` Jerome Glisse
2013-09-30 16:26 ` Linus Torvalds
2013-09-30 19:16 ` Andrea Arcangeli
2013-09-30 18:21 ` Andi Kleen
2013-09-30 19:04 ` Jerome Glisse
2013-09-29 23:06 ` [PATCH] rwsem: reduce spinlock contention in wakeup code path Davidlohr Bueso
2013-09-29 23:26 ` Linus Torvalds
2013-09-30 0:40 ` Davidlohr Bueso
2013-09-30 0:51 ` Linus Torvalds
2013-09-30 6:57 ` Ingo Molnar
2013-09-30 1:11 ` Michel Lespinasse
2013-09-30 7:05 ` Ingo Molnar
2013-09-30 16:03 ` Waiman Long
2013-09-30 10:46 ` Peter Zijlstra
2013-10-01 7:48 ` Ingo Molnar
2013-10-01 8:10 ` Peter Zijlstra [this message]
2013-09-27 19:32 ` Peter Hurley
2013-09-28 0:46 ` Waiman Long
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=20131001081011.GM3081@twins.programming.kicks-ass.net \
--to=peterz@infradead.org \
--cc=Waiman.Long@hp.com \
--cc=aarcange@redhat.com \
--cc=akpm@linux-foundation.org \
--cc=alex.shi@intel.com \
--cc=andi@firstfloor.org \
--cc=aswin@hp.com \
--cc=dave.hansen@intel.com \
--cc=davidlohr.bueso@hp.com \
--cc=linux-kernel@vger.kernel.org \
--cc=matthew.r.wilcox@intel.com \
--cc=mingo@elte.hu \
--cc=mingo@kernel.org \
--cc=peter@hurleysoftware.com \
--cc=riel@redhat.com \
--cc=scott.norton@hp.com \
--cc=tim.c.chen@linux.intel.com \
--cc=torvalds@linux-foundation.org \
--cc=walken@google.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
Powered by JetHome