linux-kernel - Re: [PATCH 02/10] mm: system wide ALLOC_NO

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:	Mon, 6 Aug 2007 15:47:30 -0700
From:	Daniel Phillips <phillips@...nq.net>
To:	Christoph Lameter <clameter@....com>
Cc:	Matt Mackall <mpm@...enic.com>,
	Peter Zijlstra <a.p.zijlstra@...llo.nl>,
	linux-kernel@...r.kernel.org, linux-mm@...ck.org,
	David Miller <davem@...emloft.net>,
	Andrew Morton <akpm@...ux-foundation.org>,
	Daniel Phillips <phillips@...gle.com>,
	Pekka Enberg <penberg@...helsinki.fi>,
	Lee Schermerhorn <Lee.Schermerhorn@...com>,
	Steve Dickson <SteveD@...hat.com>
Subject: Re: [PATCH 02/10] mm: system wide ALLOC_NO_WATERMARK

(What Peter already wrote, but in different words)

On Monday 06 August 2007 13:19, Christoph Lameter wrote:
> The solution may be as simple as configuring the reserves right and
> avoid the unbounded memory allocations.

Exactly.  That is what this patch set is about.  This is the part that 
provides some hooks to extend the traditional reserves to be able to 
handle some of the more difficult situations.

> That is possible if one 
> would make sure that the network layer triggers reclaim once in a
> while.

No.  It does no good at all for network to do a bunch of work 
reclaiming, then have some other random task (for example, a heavy 
writer) swoop in and grab the reclaimed memory before net can use it.  
Also, net allocates memory in interrupt context where shrink_caches is 
not possible.  The correct solution is to _reserve_ the memory net 
needs for vm writeout, which is in Peter's next patch set coming down 
the pipe.

Regards,

Daniel
-
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/