Comment 144 for bug 620074

I would say there are no changes. Perhaps a little bit worse.
There are still freezes with non-direct write access, e.g. while painting circles in gimp.
No freezes with direct-io, but high lattency with concurrent disk access (as before).

ext3 - direct
requests: 205.795295/s
total: W: 0.000616 / D:: 0.011195 / T: 0.011811
W: avg: 0.000000299 / min: 0.000000000 / max: 0.000007085
D: avg: 0.000005434 / min: 0.000000000 / max: 0.000100447
T: avg: 0.000005733 / min: 0.000000000 / max: 0.000100958
4294967296 Bytes (4,3 GB) kopiert, 210,281 s, 20,4 MB/s
4294967296 Bytes (4,3 GB) kopiert, 210,525 s, 20,4 MB/s

ext3
requests: 4960.868922
total: W: 0.032503 / D: 21.032077 / T: 21.064580
W: avg: 0.000000655 / min: 0.000000000 / max: 0.000069624
D: avg: 0.000423863 / min: 0.000000000 / max: 0.415194973
T: avg: 0.000424518 / min: 0.000000000 / max: 0.415195303

requests: 3588.105593/s
total: W: 0.014912 / D: 10.578434 / T: 10.593346
W: avg: 0.000000415 / min: 0.000000000 / max: 0.000077581
D: avg: 0.000294754 / min: 0.000000000 / max: 0.447073476
T: avg: 0.000295170 / min: 0.000000000 / max: 0.447073806

4294967296 Bytes (4,3 GB) kopiert, 218,708 s, 19,6 MB/s
4294967296 Bytes (4,3 GB) kopiert, 228,355 s, 18,8 MB/s

ext4 - direct
requests: 115.981745/s
total: W: 0.000344 / D: 0.016716 / T: 0.017061
W: avg: 0.000000297 / min: 0.000000110 / max: 0.000025846
D: avg: 0.000014398 / min: 0.000000650 / max: 0.000075554
T: avg: 0.000014695 / min: 0.000000990 / max: 0.000076195
4294967296 Bytes (4,3 GB) kopiert, 156,476 s, 27,4 MB/s
4294967296 Bytes (4,3 GB) kopiert, 157,78 s, 27,2 MB/s

ext4
requests: 7556.114616/s
total: W: 0.029942 / D: 9.424271 / T: 9.454213
W: avg: 0.000000396 / min: 0.000000000 / max: 0.000127857
D: avg: 0.000124722 / min: 0.000000000 / max: 0.046151790
T: avg: 0.000125119 / min: 0.000000000 / max: 0.046152130
4294967296 Bytes (4,3 GB) kopiert, 147,553 s, 29,1 MB/s
4294967296 Bytes (4,3 GB) kopiert, 151,226 s, 28,4 MB/s