Hi Fengguang, On Sat 08-10-11 12:00:36, Wu Fengguang wrote: > The test results look not good: btrfs is heavily impacted and the > other filesystems are slightly impacted. > > I'll send you the detailed logs in private emails (too large for the > mailing list). Basically I noticed many writeback_wait traces that never > appear w/o this patch. OK, thanks for running these tests. I'll have a look at detailed logs. I guess the difference can be caused by changes in redirty/requeue logic in the second patch (the changes in the first patch could possibly make several writeback_wait events from one event but never could introduce new events). I guess I'll also try to reproduce the problem since it should be pretty easy when you see such a huge regression even with 1 dd process on btrfs filesystem. > In the btrfs cases that see larger regressions, I see large fluctuations > in the writeout bandwidth and long disk idle periods. It's still a bit > puzzling how all these happen.. Yes, I don't understand it yet either... Honza > > 3.1.0-rc8-ioless6+ 3.1.0-rc8-ioless6-requeue+ > ------------------------ ------------------------ > 59.39 -82.9% 10.13 thresh=100M/btrfs-10dd-4k-8p-4096M-100M:10-X > 58.68 -80.3% 11.54 thresh=100M/btrfs-1dd-4k-8p-4096M-100M:10-X > 58.92 -80.0% 11.76 thresh=100M/btrfs-2dd-4k-8p-4096M-100M:10-X > 38.02 -1.0% 37.65 thresh=100M/ext3-10dd-4k-8p-4096M-100M:10-X > 45.20 +1.7% 45.96 thresh=100M/ext3-1dd-4k-8p-4096M-100M:10-X > 42.50 -0.8% 42.14 thresh=100M/ext3-2dd-4k-8p-4096M-100M:10-X > 47.50 -2.5% 46.32 thresh=100M/ext4-10dd-4k-8p-4096M-100M:10-X > 58.18 -3.0% 56.41 thresh=100M/ext4-1dd-4k-8p-4096M-100M:10-X > 55.79 -2.1% 54.63 thresh=100M/ext4-2dd-4k-8p-4096M-100M:10-X > 44.89 -19.3% 36.23 thresh=100M/xfs-10dd-4k-8p-4096M-100M:10-X > 58.06 -4.2% 55.64 thresh=100M/xfs-1dd-4k-8p-4096M-100M:10-X > 51.94 -1.1% 51.35 thresh=100M/xfs-2dd-4k-8p-4096M-100M:10-X > 60.29 -35.9% 38.63 thresh=1G/btrfs-100dd-4k-8p-4096M-1024M:10-X > 58.80 -33.2% 39.25 thresh=1G/btrfs-10dd-4k-8p-4096M-1024M:10-X > 58.53 -21.5% 45.93 thresh=1G/btrfs-1dd-4k-8p-4096M-1024M:10-X > 31.96 -4.7% 30.44 thresh=1G/ext3-100dd-4k-8p-4096M-1024M:10-X > 36.19 -1.0% 35.82 thresh=1G/ext3-10dd-4k-8p-4096M-1024M:10-X > 45.03 -2.7% 43.80 thresh=1G/ext3-1dd-4k-8p-4096M-1024M:10-X > 51.47 -2.6% 50.14 thresh=1G/ext4-100dd-4k-8p-4096M-1024M:10-X > 56.19 -1.0% 55.64 thresh=1G/ext4-10dd-4k-8p-4096M-1024M:10-X > 58.41 -1.0% 57.84 thresh=1G/ext4-1dd-4k-8p-4096M-1024M:10-X > 43.44 -8.4% 39.77 thresh=1G/xfs-100dd-4k-8p-4096M-1024M:10-X > 49.83 -3.3% 48.18 thresh=1G/xfs-10dd-4k-8p-4096M-1024M:10-X > 52.70 -0.8% 52.26 thresh=1G/xfs-1dd-4k-8p-4096M-1024M:10-X > 57.12 -85.5% 8.27 thresh=8M/btrfs-10dd-4k-8p-4096M-8M:10-X > 59.29 -84.7% 9.05 thresh=8M/btrfs-1dd-4k-8p-4096M-8M:10-X > 59.23 -84.9% 8.97 thresh=8M/btrfs-2dd-4k-8p-4096M-8M:10-X > 33.63 -3.3% 32.51 thresh=8M/ext3-10dd-4k-8p-4096M-8M:10-X > 48.30 -4.7% 46.03 thresh=8M/ext3-1dd-4k-8p-4096M-8M:10-X > 46.77 -4.5% 44.69 thresh=8M/ext3-2dd-4k-8p-4096M-8M:10-X > 36.58 -2.2% 35.77 thresh=8M/ext4-10dd-4k-8p-4096M-8M:10-X > 57.35 -0.3% 57.16 thresh=8M/ext4-1dd-4k-8p-4096M-8M:10-X > 52.82 -1.5% 52.04 thresh=8M/ext4-2dd-4k-8p-4096M-8M:10-X > 32.19 -4.5% 30.74 thresh=8M/xfs-10dd-4k-8p-4096M-8M:10-X > 55.86 -1.4% 55.09 thresh=8M/xfs-1dd-4k-8p-4096M-8M:10-X > 48.96 -33.1% 32.74 thresh=8M/xfs-2dd-4k-8p-4096M-8M:10-X > 1810.02 -22.1% 1410.49 TOTAL > > Thanks, > Fengguang -- Jan Kara <jack@xxxxxxx> SUSE Labs, CR -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
