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
| ||
|
Message-Id: <200801192010.20699.phillips@phunq.net> Date: Sat, 19 Jan 2008 20:10:20 -0800 From: Daniel Phillips <phillips@...nq.net> To: "Abhishek Rai" <abhishekrai@...gle.com> Cc: "Theodore Tso" <tytso@....edu>, "Christoph Hellwig" <hch@...radead.org>, "Andrew Morton" <akpm@...ux-foundation.org>, linux-kernel@...r.kernel.org, rohitseth@...gle.com, linux-ext4@...r.kernel.org Subject: Re: [CALL FOR TESTING] Make Ext3 fsck way faster [2.6.24-rc6 -mm patch] On Thursday 17 January 2008 04:47, Abhishek Rai wrote: > > if Abhishek wants to pursue it, would be to pull in all of the > > indirect blocks when the file is opened, and create an in-memory > > extent tree that would speed up access to the file. It's rarely > > worth doing this without metaclustering, since it doesn't help for > > sequential I/O, only random I/O, but with metaclustering it would > > also be a win for sequential I/O. (This would also remove the > > minor performance degradation for sequential I/O imposed by > > metaclustering, and in fact improve it slightly for really big > > files.) > > Also, since the in memory extent tree will now occupy much less > space, we can keep them cached for a much longer time which will > improve performance of random reads. The new metaclustering patch is > more amenable to this trick since it reduces fragmentation thereby > reducing the number of extents. I can see value in preemptively loading indirect blocks into the buffer cache, but is building a second-order extent tree really worth the effort? Probing the buffer cache is very fast. Regards, Daniel - 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
Powered by blists - more mailing lists