Messages in this thread | | | Date | Sun, 5 Jan 2014 17:04:56 +0800 | From | fengguang.wu@intel ... | Subject | [sched] 23f0d2093c: -12.6% regression on sparse file copy |
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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-----------------------------------------------+
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