linux-ext4 - Re: [PATCH 3/4] mm: slub: Do not take expensive steps for SLUBs speculative high-order allocations

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]

Date:	Tue, 17 May 2011 12:52:14 -0500 (CDT)
From:	Christoph Lameter <cl@...ux.com>
To:	Mel Gorman <mgorman@...e.de>
cc:	David Rientjes <rientjes@...gle.com>,
	Andrew Morton <akpm@...ux-foundation.org>,
	James Bottomley <James.Bottomley@...senpartnership.com>,
	Colin King <colin.king@...onical.com>,
	Raghavendra D Prabhu <raghu.prabhu13@...il.com>,
	Jan Kara <jack@...e.cz>, Chris Mason <chris.mason@...cle.com>,
	Pekka Enberg <penberg@...nel.org>,
	Rik van Riel <riel@...hat.com>,
	Johannes Weiner <hannes@...xchg.org>,
	linux-fsdevel <linux-fsdevel@...r.kernel.org>,
	linux-mm <linux-mm@...ck.org>,
	linux-kernel <linux-kernel@...r.kernel.org>,
	linux-ext4 <linux-ext4@...r.kernel.org>
Subject: Re: [PATCH 3/4] mm: slub: Do not take expensive steps for SLUBs
 speculative high-order allocations

On Tue, 17 May 2011, Mel Gorman wrote:

> > That is not what I meant. I would like more higher order allocations to
> > succeed. That does not mean that slubs allocation methods and flags passed
> > have to stay the same. You can change the slub behavior if it helps.
> >
>
> In this particular patch, the success rate for high order allocations
> would likely decrease in low memory conditions albeit the latency when
> calling the page allocator will be lower and the disruption to the
> system will be less (no copying or reclaim of pages). My expectation
> would be that it's cheaper for SLUB to fall back than compact memory
> or reclaim pages even if this means a slab page is smaller until more
> memory is free. However, if the "goodness" criteria is high order
> allocation success rate, the patch shouldn't be merged.

The criteria is certainly overall system performance and not a high order
allocation rate.
--
To unsubscribe from this list: send the line "unsubscribe linux-ext4" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html