linux-kernel - Re: [Linaro-mm-sig] [PATCHv17 0/11] Contiguous Memory Allocator

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <CA+K6fF6SH6BNoKgwArcqvyav4b=C5SGvymo5LS3akfD_yE_beg@mail.gmail.com>
Date:	Fri, 18 Nov 2011 13:20:48 -0800
From:	sandeep patil <psandeep.s@...il.com>
To:	Marek Szyprowski <m.szyprowski@...sung.com>
Cc:	linux-kernel@...r.kernel.org, linux-arm-kernel@...ts.infradead.org,
	linux-media@...r.kernel.org, linux-mm@...ck.org,
	linaro-mm-sig@...ts.linaro.org,
	Daniel Walker <dwalker@...eaurora.org>,
	Russell King <linux@....linux.org.uk>,
	Arnd Bergmann <arnd@...db.de>,
	Jonathan Corbet <corbet@....net>, Mel Gorman <mel@....ul.ie>,
	Michal Nazarewicz <mina86@...a86.com>,
	Dave Hansen <dave@...ux.vnet.ibm.com>,
	Jesse Barker <jesse.barker@...aro.org>,
	Kyungmin Park <kyungmin.park@...sung.com>,
	Ankita Garg <ankita@...ibm.com>,
	Andrew Morton <akpm@...ux-foundation.org>,
	KAMEZAWA Hiroyuki <kamezawa.hiroyu@...fujitsu.com>
Subject: Re: [Linaro-mm-sig] [PATCHv17 0/11] Contiguous Memory Allocator

On Fri, Nov 18, 2011 at 8:43 AM, Marek Szyprowski
<m.szyprowski@...sung.com> wrote:
> Welcome everyone once again,

> Please notice that this patch series is aimed to start further
> discussion. There are still few issues that need to be resolved before
> CMA will be really ready. The most hot problem is the issue with movable
> pages that causes migration to fail from time to time. Our investigation
> leads us to the point that these rare pages cannot be migrated because
> there are some pending io operations on them.


I am running a simple test to allocate contiguous regions and write a log on
in a file on sdcard simultaneously. I can reproduce this migration failure 100%
times with it.
when I tracked the pages that failed to migrate, I found them on the
buffer head lru
list with a reference held on the buffer_head in the page, which
causes drop_buffers()
to fail.

So, i guess my question is, until all the migration failures are
tracked down and fixed,
is there a plan to retry the contiguous allocation from a new range in
the CMA region?

~ sandeep
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/