linux-ext4 - Re: ext4 unlink performance

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 for Android: free password hash cracker in your pocket

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:	Sat, 15 Nov 2008 17:08:09 -0600
From:	Eric Sandeen <sandeen@...hat.com>
To:	linux-ext4@...r.kernel.org
Subject: Re: ext4 unlink performance

Bruce Guenter wrote:
> On Fri, Nov 14, 2008 at 09:59:14AM -0500, Theodore Tso wrote:
>> This is beginning to perhaps sound like a layout problem of some kind.
> 
> To test this theory, I ran one test where I populated the filesystem
> with ext3 and then mounted as ext4 to do the unlinking.  This produced
> unlink times comparable with ext3.  That is, the degredation is occuring
> when the filesystem is populated, not when it is cleaned.

Maybe run the unlinking activity through seekwatcher* in both cases, to
see where the IO is happening.

(also, you're right w.r.t. lvm/dm; barriers don't pass and should get
disabled after the first attempt at a barrier write).

-Eric

*http://oss.oracle.com/~mason/seekwatcher/ (also packaged for fedora,
maybe other distros as well)
--
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