Andrew Morton wrote: > Chris Mason <[EMAIL PROTECTED]> wrote: > > > Should be: it uses first-fit. > > > > > > > Looks like ext3 is just walking a list of > > > > bh/jh, maybe we can just sort the silly thing? > > > > > > The IO scheduler is supposed to do that. > > > > > > But I don't know what's causing this. > > > > I had high hopes of blaming cfq, but deadline gives the same results: > > > > create dir kernel-0 222MB in 5.38 seconds (41.33 MB/s) > > ... [ ~30MB/s here ] ... > > create dir kernel-7 222MB in 8.11 seconds (27.42 MB/s) > > create dir kernel-8 222MB in 18.39 seconds (12.09 MB/s) > > create dir kernel-9 222MB in 6.91 seconds (32.18 MB/s) > > create dir kernel-10 222MB in 24.32 seconds (9.14 MB/s) > > create dir kernel-11 222MB in 12.06 seconds (18.44 MB/s) > > create dir kernel-12 222MB in 10.95 seconds (20.31 MB/s) > > > > The good news is that if you let it run long enough, the times > > stabilize. The bad news is: > > > > create dir kernel-86 222MB in 15.85 seconds (14.03 MB/s) > > create dir kernel-87 222MB in 28.67 seconds (7.76 MB/s) > > create dir kernel-88 222MB in 18.12 seconds (12.27 MB/s) > > create dir kernel-89 222MB in 19.77 seconds (11.25 MB/s) > > well hang on. Doesn't this just mean that the first few runs were writing > into pagecache and the later ones were blocking due to dirty-memory > limits? > > Or do you have a sync in there? > > > echo 2048 > /sys/block/..../nr_requests didn't do it either. > > > > I guess I'll have systemtap tell me more about the log flushing.
Try these: # echo anticipatory > /sys/block/.../scheduler # echo 0 > /sys/block/.../iosched/antic_expire # echo 192 > /sys/block/.../max_sectors_kb # echo 192 > /sys/block/.../read_ahead_kb These give me best performance, but most noticeably antic_expire > 0 leaves the IOScheduler in a apparent limbo. see http://bugzilla.kernel.org/show_bug.cgi?id=5900 Thanks! -- Al - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
