linux-kernel - Re: [PATCH] Improve heuristic detecting sequential reads

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: <20070410164540.6d10ddd7.akpm@linux-foundation.org>
Date:	Tue, 10 Apr 2007 16:45:40 -0700
From:	Andrew Morton <akpm@...ux-foundation.org>
To:	Andi Kleen <andi@...stfloor.org>
Cc:	Jan Kara <jack@...e.cz>, linux-kernel@...r.kernel.org,
	npiggin@...e.de, WU Fengguang <wfg@...l.ustc.edu.cn>
Subject: Re: [PATCH] Improve heuristic detecting sequential reads

On 11 Apr 2007 00:56:51 +0200
Andi Kleen <andi@...stfloor.org> wrote:

> Jan Kara <jack@...e.cz> writes:
> 
> >   Hello!
> > 
> >   In thread http://lkml.org/lkml/2007/3/9/403, we discussed a problem
> > with the current heuristic for detecting sequential IO in
> > do_generic_mapping_read() - for small files a page is marked as accessed
> > only once which can cause a performance problems.
> >   Attached is a patch that improves the heuristic by introducing a
> > ra.offset variable so now we can reliably detect sequetial reads.
> > The patch replaces Nick's patch from http://lkml.org/lkml/2007/3/15/177
> > (Nick has acked to replace the patch). Could you please put the patch
> > into -mm?
> 
> There's a much more complete patchkit for this that gets reposted
> regularly on l-k. Perhaps it would make sense to test that first?

adaptive readahead?  Has been in -mm for a year.  Problem is, it is
_so_ complete that I just don't know how to merge it.  It's huge, and
only Wu understands it. So it's really rather stuck.
-
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/