On 20030203 (Mon) at 1117:44 -0800, Andrew Morton wrote: > hum. > > So you have an operation which takes 30 seconds and generates 30 megabytes of > dirty data. My wild guess would be that the first five seconds' worth of > data are splattered all over the disk, and that the holes in that write > pattern are filled in later in the run. > > So if a filesystem happens to decide to write the data after the first five > seconds, there is little request merging. But if the filesystem were to wait > the whole thirty seconds then voila - all the holes are filled in and there's > a lot of request merging. > > Well. It's a theory. If you mount your data=ordered fs with `-o commit=60', > what happens? Recalling the times reported yesterday, in writeback it's 4 minutes and change; data=ordered, roughly 27 minutes; the commit=60 result is about the same as commit=5, as follows: # umount /xtrn # mount -t ext3 -o data=ordered,commit=60 /dev/sdc1 /xtrn # time bogofilter -v -s -d /xtrn/db <spam_corpus # 5898549 words, 14600 messages real 28m9.866s user 2m30.750s sys 0m46.700s -- | G r e g L o u i s | gpg public key: | | http://www.bgl.nu/~glouis | finger greg@bgl.nu | | Help free our mailboxes. Include | | http://wecanstopspam.org in your signature. | _______________________________________________ Ext3-users@redhat.com https://listman.redhat.com/mailman/listinfo/ext3-users
