linux-kernel - Re: [15/17] SLUB: Support virtual fallback via SLAB

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: <1191002119.18147.80.camel@lappy>
Date:	Fri, 28 Sep 2007 19:55:19 +0200
From:	Peter Zijlstra <a.p.zijlstra@...llo.nl>
To:	Christoph Lameter <clameter@....com>
Cc:	Nick Piggin <nickpiggin@...oo.com.au>,
	Christoph Hellwig <hch@....de>, Mel Gorman <mel@...net.ie>,
	linux-fsdevel@...r.kernel.org, linux-kernel@...r.kernel.org,
	David Chinner <dgc@....com>, Jens Axboe <jens.axboe@...cle.com>
Subject: Re: [15/17] SLUB: Support virtual fallback via SLAB_VFALLBACK


On Fri, 2007-09-28 at 10:33 -0700, Christoph Lameter wrote:

> Again I have not seen any fallbacks to vmalloc in my testing. What we are 
> doing here is mainly to address your theoretical cases that we so far have 
> never seen to be a problem and increase the reliability of allocations of
> page orders larger than 3 to a usable level. So far I have so far not 
> dared to enable orders larger than 3 by default.

take a recent -mm kernel, boot with mem=128M.

start 2 processes that each mmap a separate 64M file, and which does
sequential writes on them. start a 3th process that does the same with
64M anonymous.

wait for a while, and you'll see order=1 failures.



-
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/