linux-kernel - Re: [PATCH 2/8] readahead: make default readahead size a kernel parameter

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] [day] [month] [year] [list]

Message-ID: <20111130160908.GE4541@quack.suse.cz>
Date:	Wed, 30 Nov 2011 17:09:08 +0100
From:	Jan Kara <jack@...e.cz>
To:	Wu Fengguang <fengguang.wu@...el.com>
Cc:	Christian Ehrhardt <ehrhardt@...ux.vnet.ibm.com>,
	Dave Chinner <david@...morbit.com>, Jan Kara <jack@...e.cz>,
	Christoph Hellwig <hch@...radead.org>,
	Andrew Morton <akpm@...ux-foundation.org>,
	Linux Memory Management List <linux-mm@...ck.org>,
	"linux-fsdevel@...r.kernel.org" <linux-fsdevel@...r.kernel.org>,
	Ankit Jain <radical@...il.com>, Rik van Riel <riel@...hat.com>,
	Nikanth Karthikesan <knikanth@...e.de>,
	LKML <linux-kernel@...r.kernel.org>,
	Andi Kleen <andi@...stfloor.org>
Subject: Re: [PATCH 2/8] readahead: make default readahead size a kernel
 parameter

On Wed 30-11-11 21:29:28, Wu Fengguang wrote:
> > cat /etc/udev/rules.d/60-readahead.rules
> > # 
> >  
> >  
> > 
> > # Rules to set an increased default max readahead size for s390 disk 
> > devices 
> >  
> > 
> > # This file should be installed in /etc/udev/rules.d 
> >  
> >  
> > 
> > # 
> >  
> > SUBSYSTEM!="block", GOTO="ra_end" 
> > 
> > ACTION!="add", GOTO="ra_end" 
> > 
> > # on device add set initial readahead to 512 (instead of in kernel 128) 
> > 
> > KERNEL=="sd*[!0-9]", ATTR{queue/read_ahead_kb}="512" 
> > 
> > KERNEL=="dasd*[!0-9]", ATTR{queue/read_ahead_kb}="512" 
> 
> So SLES (@s390 and maybe more) is already shipping with 512kb
> readahead size? Good to know this!
  SLES (and openSUSE) since about 2.6.16 times is shipping with 512kb
readahead on everything... With some types of storage it makes a
significant difference.

								Honza
-- 
Jan Kara <jack@...e.cz>
SUSE Labs, CR
--
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/