linux-kernel - Re: [PATCH, RFC] ext4: Use preallocation when reading from the inode table

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: <20080923101613.58768083@lxorguk.ukuu.org.uk>
Date:	Tue, 23 Sep 2008 10:16:13 +0100
From:	Alan Cox <alan@...rguk.ukuu.org.uk>
To:	"Theodore Ts'o" <tytso@....edu>
Cc:	linux-ext4@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH, RFC] ext4: Use preallocation when reading from the
 inode table

On Mon, 22 Sep 2008 20:35:23 -0400
"Theodore Ts'o" <tytso@....edu> wrote:

> 
> With modern hard drives, reading 64k takes roughly the same time as
> reading a 4k block.  So request adjacent inode table blocks to reduce
> the time it takes when iterating over directories (especially when doing
> this in htree sort order) in a cold cache case.  With this patch, the
> time it takes to run "git status" on a kernel tree after flushing the
> caches via "echo 3 > /proc/sys/vm/drop_caches", is reduced by 21%.
> 
> Signed-off-by: "Theodore Ts'o" <tytso@....edu>

Acked-by: Alan Cox <alan@...hat.com>

I'm actually suprised that 16 is the magic tuning number you've used and
a bigger one isn't even more of a win

Alan
--
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/