Re: 2.4.8preX VM problems

Andrew Tridgell
2001-08-01T10:59:18Z

Marcelo,

> The following patch sets the zone free target to freepages.high. Can you
> test it ? (I tried here and got the expected results)

Running just that patch against 2.4.8pre3 gives:

[root@fraud /root]# ~/readfiles /dev/ddisk
198 MB 198.084 MB/sec
386 MB 188.634 MB/sec
570 MB 183.827 MB/sec
743 MB 172.5 MB/sec
810 MB 67.0501 MB/sec
862 MB 52.1381 MB/sec
901 MB 37.9501 MB/sec
957 MB 55.8253 MB/sec
998 MB 41.1541 MB/sec
1046 MB 48.1661 MB/sec
1088 MB 40.3898 MB/sec
1140 MB 50.8782 MB/sec
1183 MB 42.5749 MB/sec
1229 MB 46.1378 MB/sec
1275 MB 44.8515 MB/sec
1319 MB 43.5389 MB/sec
1368 MB 47.5747 MB/sec
1411 MB 42.8134 MB/sec

which is much better, but is pretty poor performance for a null
device.

Running with that latest patch plus the patch you sent previously
gives roughly the same result. Also, kswapd chews lots of cpu during
these runs:

CPU0 states: 0.0% user, 79.0% system, 0.0% nice, 20.4% idle
CPU1 states: 0.2% user, 77.1% system, 0.0% nice, 22.1% idle
Mem: 2059088K av, 892256K used, 1166832K free, 0K shrd, 784972K buff
Swap: 1052216K av, 0K used, 1052216K free 10072K cached

PID USER PRI NI SIZE RSS SHARE LC STAT %CPU %MEM TIME COMMAND
608 root 19 0 452 452 328 1 R 95.2 0.0 1:23 readfiles
5 root 14 0 0 0 0 1 SW 58.3 0.0 0:52 kswapd
6 root 9 0 0 0 0 1 RW 2.1 0.0 0:01 kreclaimd