From mboxrd@z Thu Jan 1 00:00:00 1970 From: Chris Mason Subject: Re: [PATCH] new data logging and quota patches available Date: 12 Mar 2003 08:41:19 -0500 Message-ID: <1047476478.8215.517.camel@tiny.suse.com> References: <1046922372.2161.275.camel@tiny.suse.com> <3E66C88E.40207@mb.tu-ilmenau.de> <3E69FA70.5030601@mb.tu-ilmenau.de> <1047227975.8215.150.camel@tiny.suse.com> <3E6B74C0.5050702@mb.tu-ilmenau.de> <1047230647.8219.161.camel@tiny.suse.com> <3E6B7C61.9050405@mb.tu-ilmenau.de> <1047415578.8215.383.camel@tiny.suse.com> <20030312103800.A9291@namesys.com> <1047475349.8219.499.camel@tiny.suse.com> <20030312162850.A1840@namesys.com> Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Return-path: list-help: list-unsubscribe: list-post: Errors-To: flx@namesys.com In-Reply-To: <20030312162850.A1840@namesys.com> List-Id: Content-Type: text/plain; charset="us-ascii" To: Oleg Drokin Cc: Manuel Krause , reiserfs-list On Wed, 2003-03-12 at 08:28, Oleg Drokin wrote: > > > then it really only helps on long sequential reads. > > That's true, but it made no difference for you on SCSI for sequentional reads too. That's true, we were comparing your IDE drive results with my scsi for reading a single big file. It probably didn't help for the single big file because of the page cache readahead triggering parallel tree searches. But Manuel's test is different, it's doing a long sequential read of multiple files. The page cache code only does readahead on one file at a time, reading fileA won't trigger a parallel read of the indirect items for fileB. search_reada will work better in that case, since it will grab indirect items for fileB. Also, it will do readahead on the directory items, probably making directory scanning faster. -chris