From: Peter Zijlstra <peterz@infradead.org>
To: Christoph Lameter <cl@linux.com>
Cc: Al Viro <viro@ZenIV.linux.org.uk>,
Vince Weaver <vincent.weaver@maine.edu>,
linux-kernel@vger.kernel.org, Paul Mackerras <paulus@samba.org>,
Ingo Molnar <mingo@redhat.com>,
Arnaldo Carvalho de Melo <acme@ghostprotocols.net>,
trinity@vger.kernel.org
Subject: Re: OOPS in perf_mmap_close()
Date: Thu, 23 May 2013 17:24:58 +0200 [thread overview]
Message-ID: <20130523152458.GD23650@twins.programming.kicks-ass.net> (raw)
In-Reply-To: <0000013ed1b8d0cc-ad2bb878-51bd-430c-8159-629b23ed1b44-000000@email.amazonses.com>
On Thu, May 23, 2013 at 02:09:10PM +0000, Christoph Lameter wrote:
> On Thu, 23 May 2013, Peter Zijlstra wrote:
>
> > Right it doesn't. I think the easiest solution for now is to not copy the VMA
> > on fork().
>
> Right. Pinned pages are not inherited. If a page is unpinned then that is
> going to happen for all address spaces that reference the page.
>
> > But I totally missed patch bc3e53f682d that introduced pinned_vm, AFAICT that
> > also wrecked some accounting. We should still account both against
> > RLIMIT_MEMLOCK.
>
> The point of the patch was to unwreck accounting. Before the patch mlocked
> pages were counted twice which resulted in stramge VM scenarios where more
> pages were mlocked than memory available. Note that a pinned page may also
> be mlocked.
>
> Simply adding the two will reintroduce the problems that were fixed by the
> patch.
The patch completely fails to explain how RLIMIT_LOCKED is supposed to
deal with pinned vs locked. Perf used to account its pages against
RLIMIT_LOCKED, with the patch it compares pinned against RLIMIT_LOCKED
but completely discards any possible locked pages.
IMO that's broken.
next prev parent reply other threads:[~2013-05-23 15:24 UTC|newest]
Thread overview: 65+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-05-22 19:35 OOPS in perf_mmap_close() Vince Weaver
2013-05-22 19:35 ` Vince Weaver
2013-05-22 23:56 ` Vince Weaver
2013-05-23 3:48 ` Vince Weaver
2013-05-23 4:48 ` Al Viro
2013-05-23 10:41 ` Peter Zijlstra
2013-05-23 14:09 ` Christoph Lameter
2013-05-23 15:24 ` Peter Zijlstra [this message]
2013-05-23 16:12 ` Christoph Lameter
2013-05-23 16:39 ` Peter Zijlstra
2013-05-23 17:59 ` Christoph Lameter
2013-05-23 19:24 ` Peter Zijlstra
2013-05-24 14:01 ` [RFC][PATCH] mm: Fix RLIMIT_MEMLOCK Peter Zijlstra
2013-05-24 14:01 ` Peter Zijlstra
2013-05-24 15:40 ` Christoph Lameter
2013-05-24 15:40 ` Christoph Lameter
2013-05-26 1:11 ` KOSAKI Motohiro
2013-05-26 1:11 ` KOSAKI Motohiro
2013-05-28 16:19 ` Christoph Lameter
2013-05-28 16:19 ` Christoph Lameter
2013-05-27 6:48 ` Peter Zijlstra
2013-05-27 6:48 ` Peter Zijlstra
2013-05-28 16:37 ` Christoph Lameter
2013-05-28 16:37 ` Christoph Lameter
2013-05-29 7:58 ` [regression] " Ingo Molnar
2013-05-29 7:58 ` Ingo Molnar
2013-05-29 19:53 ` KOSAKI Motohiro
2013-05-29 19:53 ` KOSAKI Motohiro
2013-05-30 6:32 ` Ingo Molnar
2013-05-30 6:32 ` Ingo Molnar
2013-05-30 20:42 ` KOSAKI Motohiro
2013-05-30 20:42 ` KOSAKI Motohiro
2013-05-31 9:27 ` Ingo Molnar
2013-05-31 9:27 ` Ingo Molnar
2013-05-30 18:30 ` Peter Zijlstra
2013-05-30 18:30 ` Peter Zijlstra
2013-05-30 19:59 ` Pekka Enberg
2013-05-30 19:59 ` Pekka Enberg
2013-05-30 21:00 ` KOSAKI Motohiro
2013-05-30 21:00 ` KOSAKI Motohiro
2013-05-23 12:52 ` OOPS in perf_mmap_close() Peter Zijlstra
2013-05-23 14:10 ` Vince Weaver
2013-05-23 15:26 ` Peter Zijlstra
2013-05-23 15:47 ` Vince Weaver
2013-05-23 23:40 ` Vince Weaver
2013-05-24 9:21 ` Peter Zijlstra
2013-05-28 8:55 ` Peter Zijlstra
2013-05-28 13:29 ` [tip:perf/urgent] perf: Fix perf mmap bugs tip-bot for Peter Zijlstra
2013-06-04 8:44 ` Peter Zijlstra
2013-06-05 11:55 ` Peter Zijlstra
2013-06-19 18:38 ` [tip:perf/core] perf: Fix mmap() accounting hole tip-bot for Peter Zijlstra
2013-05-28 16:19 ` OOPS in perf_mmap_close() Vince Weaver
2013-05-28 18:22 ` Vince Weaver
2013-05-29 7:44 ` Peter Zijlstra
2013-05-29 13:17 ` Vince Weaver
2013-05-29 19:18 ` Vince Weaver
2013-05-30 7:25 ` Peter Zijlstra
2013-05-30 12:51 ` Vince Weaver
2013-05-31 15:46 ` Peter Zijlstra
2013-06-03 13:26 ` Peter Zijlstra
2013-06-03 17:18 ` Peter Zijlstra
2013-06-03 19:25 ` Peter Zijlstra
2013-06-05 15:54 ` Vince Weaver
2013-06-05 16:54 ` Peter Zijlstra
2013-05-29 8:07 ` Ingo Molnar
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