lkml.org 
[lkml]   [2009]   [Sep]   [27]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
SubjectRe: IO scheduler based IO controller V10
From
Date
My dd vs load non-cached binary woes seem to be coming from backmerge.

#if 0 /*MIKEDIDIT sand in gearbox?*/
/*
* See if our hash lookup can find a potential backmerge.
*/
__rq = elv_rqhash_find(q, bio->bi_sector);
if (__rq && elv_rq_merge_ok(__rq, bio)) {
*req = __rq;
return ELEVATOR_BACK_MERGE;
}
#endif

- = stock = 0
+ = /sys/block/sdb/queue/nomerges = 1
x = backmerge disabled

quantum = 1 Avg
dd pre 58.4 52.5 56.1 61.6 52.3 56.1- MB/s virgin/foo
59.6 54.4 53.0 56.1 58.6 56.3+ 1.003
53.8 56.6 54.7 50.7 59.3 55.0x .980
perf stat 2.87 0.91 1.64 1.41 0.90 1.5- Sec
2.61 1.14 1.45 1.43 1.47 1.6+ 1.066
1.07 1.19 1.20 1.24 1.37 1.2x .800
dd post 56.6 61.0 66.3 64.7 60.9 61.9-
54.0 59.3 61.1 58.3 58.9 58.3+ .941
54.3 60.2 59.6 60.6 60.3 59.0x .953

quantum = 2
dd pre 59.7 62.4 58.9 65.3 60.3 61.3-
49.4 51.9 58.7 49.3 52.4 52.3+ .853
58.3 52.8 53.1 50.4 59.9 54.9x .895
perf stat 5.81 6.09 6.24 10.13 6.21 6.8-
2.48 2.10 3.23 2.29 2.31 2.4+ .352
2.09 2.73 1.72 1.96 1.83 2.0x .294
dd post 64.0 62.6 64.2 60.4 61.1 62.4-
52.9 56.2 49.6 51.3 51.2 52.2+ .836
54.7 60.9 56.0 54.0 55.4 56.2x .900

quantum = 3
dd pre 65.5 57.7 54.5 51.1 56.3 57.0-
58.1 53.9 52.2 58.2 51.8 54.8+ .961
60.5 56.5 56.7 55.3 54.6 56.7x .994
perf stat 14.01 13.71 8.35 5.35 8.57 9.9-
1.84 2.30 2.14 2.10 2.45 2.1+ .212
2.12 1.63 2.54 2.23 2.29 2.1x .212
dd post 59.2 49.1 58.8 62.3 62.1 58.3-
59.8 53.2 55.2 50.9 53.7 54.5+ .934
56.1 61.9 51.9 54.3 53.1 55.4x .950

quantun = 4
dd pre 57.2 52.1 56.8 55.2 61.6 56.5-
48.7 55.4 51.3 49.7 54.5 51.9+ .918
55.8 54.5 50.3 56.4 49.3 53.2x .941
perf stat 11.98 1.61 9.63 16.21 11.13 10.1-
2.29 1.94 2.68 2.46 2.45 2.3+ .227
3.01 1.84 2.11 2.27 2.30 2.3x .227
dd post 57.2 52.6 62.2 49.3 50.2 54.3-
50.1 54.5 58.4 54.1 49.0 53.2+ .979
52.9 53.2 50.6 53.2 50.5 52.0x .957




\
 
 \ /
  Last update: 2009-09-27 08:57    [W:0.161 / U:2.692 seconds]
©2003-2018 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site