Bug#540012: Low perf again.
Having running 2.6.30 for 6 days and usual load:
$ dd if=/dev/zero of=./test.img bs=572041216 count=1
1+0 records in
1+0 records out
572041216 bytes (572 MB) copied, 22.033 seconds, 26.0 MB/s
During dd all cpu cores (I have q6600) are busy doing io (according to top).
Seems like this happens when RAM starvation. I have 2 virtulabox
running, (firefox and xorg also eats memory).
Here are memory reports:
Mem: 4061884k total, 3509840k used, 552044k free, 2992k buffers
Swap: 9936160k total, 796940k used, 9139220k free, 405868k cached
$ free
total used free shared buffers cached
Mem: 4061884 3571860 490024 0 4516 430576
-/+ buffers/cache: 3136768 925116
Swap: 9936160 762060 9174100
$ vmstat
procs -----------memory---------- ---swap-- -----io---- -system-- ----cpu----
r b swpd free buff cache si so bi bo in cs us sy id wa
0 1 761984 476016 5456 443268 1 2 21 24 5 16 4 4 91 1
During test no other cpu/io applications was running. You can see
%util is 0,00, then it grows to 100% as I run dd.
$ iostat -xdk 1
Linux 2.6.30-1-amd64 (pc-paul) 12.08.2009 _x86_64_ (4 CPU)
Device: rrqm/s wrqm/s r/s w/s rkB/s wkB/s
avgrq-sz avgqu-sz await svctm %util
sda 0,00 0,00 0,00 0,00 0,00 0,00
0,00 0,00 0,00 0,00 0,00
Device: rrqm/s wrqm/s r/s w/s rkB/s wkB/s
avgrq-sz avgqu-sz await svctm %util
sda 0,00 1797,00 4,00 48,00 16,00 4300,00
166,00 4,13 12,92 1,54 8,00
Device: rrqm/s wrqm/s r/s w/s rkB/s wkB/s
avgrq-sz avgqu-sz await svctm %util
sda 0,00 10039,00 1,00 208,00 4,00 20232,00
193,65 111,99 289,97 4,57 95,60
Device: rrqm/s wrqm/s r/s w/s rkB/s wkB/s
avgrq-sz avgqu-sz await svctm %util
sda 3,00 7305,00 7,00 95,00 40,00 31848,00
625,25 141,63 668,04 9,80 100,00
Device: rrqm/s wrqm/s r/s w/s rkB/s wkB/s
avgrq-sz avgqu-sz await svctm %util
sda 0,00 11273,00 0,00 131,00 0,00 46428,00
708,82 145,53 559,66 7,79 102,00
Device: rrqm/s wrqm/s r/s w/s rkB/s wkB/s
avgrq-sz avgqu-sz await svctm %util
sda 0,00 3414,00 5,00 121,00 52,00 25248,00
401,59 148,50 1014,38 7,78 98,00
Device: rrqm/s wrqm/s r/s w/s rkB/s wkB/s
avgrq-sz avgqu-sz await svctm %util
sda 0,00 3300,00 6,00 184,00 84,00 14244,00
150,82 150,96 1271,14 5,26 100,00
Device: rrqm/s wrqm/s r/s w/s rkB/s wkB/s
avgrq-sz avgqu-sz await svctm %util
sda 0,00 5441,00 0,00 190,00 0,00 21544,00
226,78 146,50 790,40 5,26 100,00
Device: rrqm/s wrqm/s r/s w/s rkB/s wkB/s
avgrq-sz avgqu-sz await svctm %util
sda 0,00 11737,00 0,00 243,00 0,00 27644,00
227,52 145,88 907,36 4,12 100,00
Device: rrqm/s wrqm/s r/s w/s rkB/s wkB/s
avgrq-sz avgqu-sz await svctm %util
sda 0,00 11278,00 0,00 160,00 0,00 42060,00
525,75 142,84 751,67 6,25 100,00
Device: rrqm/s wrqm/s r/s w/s rkB/s wkB/s
avgrq-sz avgqu-sz await svctm %util
sda 0,00 2029,00 22,00 103,00 576,00 31096,00
506,75 139,27 889,86 8,00 100,00
Device: rrqm/s wrqm/s r/s w/s rkB/s wkB/s
avgrq-sz avgqu-sz await svctm %util
sda 10,00 5433,00 132,00 108,00 2180,00 12148,00
119,40 131,40 585,70 4,17 100,00
Device: rrqm/s wrqm/s r/s w/s rkB/s wkB/s
avgrq-sz avgqu-sz await svctm %util
sda 3,00 2583,00 41,00 71,00 548,00 14648,00
271,36 145,98 637,57 8,93 100,00
Device: rrqm/s wrqm/s r/s w/s rkB/s wkB/s
avgrq-sz avgqu-sz await svctm %util
sda 0,00 12295,00 30,00 133,00 400,00 26524,00
330,36 142,97 1167,46 6,13 100,00
Device: rrqm/s wrqm/s r/s w/s rkB/s wkB/s
avgrq-sz avgqu-sz await svctm %util
sda 0,00 15302,00 28,00 245,00 552,00 70736,00
522,26 263,49 1192,06 6,81 186,00
Device: rrqm/s wrqm/s r/s w/s rkB/s wkB/s
avgrq-sz avgqu-sz await svctm %util
sda 0,00 2500,00 0,00 8,00 0,00 3936,00
984,00 22,10 1179,00 17,50 14,00
Device: rrqm/s wrqm/s r/s w/s rkB/s wkB/s
avgrq-sz avgqu-sz await svctm %util
sda 0,00 7938,00 15,00 112,00 152,00 28560,00
452,16 143,15 835,56 7,87 100,00
Device: rrqm/s wrqm/s r/s w/s rkB/s wkB/s
avgrq-sz avgqu-sz await svctm %util
sda 3,00 642,00 113,00 32,00 1468,00 6196,00
105,71 121,22 372,39 6,90 100,00
Device: rrqm/s wrqm/s r/s w/s rkB/s wkB/s
avgrq-sz avgqu-sz await svctm %util
sda 0,00 15,00 58,00 89,00 692,00 28660,00
399,35 103,12 1148,60 6,80 100,00
$ cat /sys/block/sda/queue/scheduler
noop anticipatory deadline [cfq]
Can't reproduce on 2.6.31 (need memory hog applications to be running).
--
rmrfchik.
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