lkml.org 
[lkml]   [2014]   [Jan]   [5]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
Subject[sched] 23f0d2093c: -12.6% regression on sparse file copy
Hi Joonsoo,

We noticed the below changes for commit 23f0d2093c ("sched: Factor out
code to should_we_balance()") in test vm-scalability/300s-lru-file-readtwice

95a79b805b935f4 23f0d2093c789e612185180c4
--------------- -------------------------
==> 4.45 ~ 5% +1777.7% 83.60 ~ 5% vm-scalability.stddev
==> 14966511 ~ 0% -12.6% 13084545 ~ 2% vm-scalability.throughput
38 ~ 9% +406.3% 193 ~ 7% proc-vmstat.kswapd_low_wmark_hit_quickly
610823 ~ 0% -41.4% 357990 ~ 0% softirqs.SCHED
5.424e+08 ~ 0% -38.5% 3.338e+08 ~ 6% proc-vmstat.pgdeactivate
4.68e+08 ~ 0% -37.5% 2.924e+08 ~ 6% proc-vmstat.pgrefill_normal
5.549e+08 ~ 0% -37.1% 3.491e+08 ~ 6% proc-vmstat.pgactivate
14938509 ~ 1% +27.0% 18974176 ~ 1% vmstat.memory.free
978771 ~ 1% +23.9% 1212704 ~ 3% numa-vmstat.node2.nr_free_pages
3747434 ~ 0% +21.7% 4560196 ~ 2% proc-vmstat.nr_free_pages
==> 1.353e+08 ~ 0% +18.8% 1.607e+08 ~ 0% proc-vmstat.numa_foreign
1.353e+08 ~ 0% +18.8% 1.607e+08 ~ 0% proc-vmstat.numa_miss
1.353e+08 ~ 0% +18.8% 1.607e+08 ~ 0% proc-vmstat.numa_other
3936842 ~ 1% +22.2% 4812045 ~ 4% numa-meminfo.node2.MemFree
21803812 ~ 0% +17.7% 25661536 ~ 4% numa-vmstat.node3.numa_foreign
73701524 ~ 0% +15.0% 84769542 ~ 0% proc-vmstat.pgscan_direct_dma32
73700683 ~ 0% +15.0% 84768687 ~ 0% proc-vmstat.pgsteal_direct_dma32
3.101e+08 ~ 0% +11.2% 3.448e+08 ~ 0% proc-vmstat.pgsteal_direct_normal
3.103e+08 ~ 0% +11.2% 3.449e+08 ~ 0% proc-vmstat.pgscan_direct_normal
45613907 ~ 0% +12.6% 51342974 ~ 3% numa-vmstat.node0.numa_other
795639 ~ 0% -48.6% 409113 ~13% time.voluntary_context_switches
375 ~ 0% +6.1% 398 ~ 0% time.elapsed_time
9427 ~ 0% -5.8% 8880 ~ 0% time.percent_of_cpu_this_job_got

The test case basically does

for i in `seq 1 $nr_cpu`
do
create_sparse_file huge-$i
dd if=huge-$i of=/dev/null &
dd if=huge-$i of=/dev/null &
done

where nr_cpu=120 (test box is a 4-socket ivybridge system).

The change looks stable, each point below is a sample run:

vm-scalability.stddev

120 ++-------------------------------------------------------------------+
| |
100 ++ * * |
| *.*** : ** : * * * * * |
** * *.** * : * :*.* :: .* : : * :* * : .* : .* * .**|
80 ++ * * *. : * *: ** : :: : * :.* * * * ** : :* *
| * * : *** * * * :** |
60 ++ * * |
| |
40 ++ |
| |
| |
20 ++ |
| O OO OO OOO O OO O |
0 OO--O--O------OO----OO-----------------------------------------------+



\
 
 \ /
  Last update: 2014-01-05 10:41    [W:0.056 / U:1.004 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site