From: Davidlohr Bueso <dave@stgolabs.net>
To: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Jason Low <jason.low2@hp.com>, Ingo Molnar <mingo@kernel.org>,
Sasha Levin <sasha.levin@oracle.com>,
Peter Zijlstra <peterz@infradead.org>,
LKML <linux-kernel@vger.kernel.org>,
Dave Jones <davej@codemonkey.org.uk>
Subject: Re: sched: softlockups in multi_cpu_stop
Date: Fri, 06 Mar 2015 12:00:00 -0800 [thread overview]
Message-ID: <1425672000.19505.57.camel@stgolabs.net> (raw)
In-Reply-To: <1425671702.19505.54.camel@stgolabs.net>
On Fri, 2015-03-06 at 11:55 -0800, Davidlohr Bueso wrote:
> On Fri, 2015-03-06 at 11:32 -0800, Linus Torvalds wrote:
>
> > IOW, I wonder if we could special-case the common non-IO
> > fault-handling path something along the lines of:
> >
> > - look up the vma in the vma lookup cache
>
> But you'd still need mmap_sem there to at least get the VMA's first
> value.
Incomplete msg... what I'm getting at is that one way or another
mmap_sem contention is easy to hit -- yes, avoiding it in IO paths is
obviously good for hold times. But I also think that it protects way too
much, ie making pthread intense workloads really suck as well.
next prev parent reply other threads:[~2015-03-06 20:00 UTC|newest]
Thread overview: 44+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-03-02 7:45 sched: softlockups in multi_cpu_stop Sasha Levin
[not found] ` <CAMiJ5CVWvUhGK=MWYB_CTNs901p=jsT4i5gkWTaHih7qdQdkFQ@mail.gmail.com>
2015-03-04 5:44 ` Rafael David Tinoco
2015-03-06 11:27 ` Sasha Levin
2015-03-06 12:32 ` Ingo Molnar
2015-03-06 14:34 ` Rafael David Tinoco
2015-03-06 14:45 ` Sasha Levin
2015-03-06 15:46 ` Sasha Levin
2015-03-06 17:19 ` Davidlohr Bueso
2015-03-06 18:02 ` Sasha Levin
2015-03-06 21:59 ` Sasha Levin
2015-03-06 18:57 ` Jason Low
2015-03-06 19:05 ` Linus Torvalds
2015-03-06 19:20 ` Davidlohr Bueso
2015-03-06 19:32 ` Linus Torvalds
2015-03-06 19:45 ` Davidlohr Bueso
2015-03-06 19:55 ` Davidlohr Bueso
2015-03-06 20:00 ` Davidlohr Bueso [this message]
2015-03-06 21:42 ` Linus Torvalds
2015-03-06 19:29 ` Jason Low
2015-03-06 21:12 ` Jason Low
2015-03-06 21:24 ` Linus Torvalds
2015-03-07 1:53 ` Jason Low
2015-03-06 22:15 ` Davidlohr Bueso
2015-03-07 1:55 ` Ming Lei
2015-03-07 2:07 ` Davidlohr Bueso
2015-03-07 2:10 ` Ming Lei
2015-03-07 2:26 ` Davidlohr Bueso
2015-03-07 2:29 ` Davidlohr Bueso
2015-03-07 2:55 ` Ming Lei
2015-03-07 3:10 ` Davidlohr Bueso
2015-03-07 3:19 ` Ming Lei
2015-03-07 3:41 ` Davidlohr Bueso
2015-03-07 2:56 ` Jason Low
2015-03-07 3:08 ` Ming Lei
2015-03-07 3:10 ` Davidlohr Bueso
2015-03-07 3:17 ` Jason Low
2015-03-07 3:39 ` Ming Lei
2015-03-07 3:53 ` Jason Low
2015-03-07 1:58 ` Jason Low
2015-03-07 4:31 ` Jason Low
2015-03-07 4:44 ` Davidlohr Bueso
2015-03-07 6:45 ` Jason Low
2015-03-07 5:54 ` Ming Lei
2015-03-07 6:57 ` Jason Low
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