diff options
| author | Paul Turner <pjt@google.com> | 2011-11-07 20:26:33 -0800 |
|---|---|---|
| committer | Ingo Molnar <mingo@elte.hu> | 2011-11-16 08:48:18 +0100 |
| commit | 56f570e512eeb5b412cb3a62234adc446a8eb32b (patch) | |
| tree | cabaea188d6e35c077abc34fda40cc83aea9ea37 /init | |
| parent | fccfdc6f0d8c83c854eeb6d93aa158f0e551bd49 (diff) | |
sched: Use jump labels to reduce overhead when bandwidth control is inactive
Now that the linkage of jump-labels has been fixed they show a measurable
improvement in overhead for the enabled-but-unused case.
Workload is:
'taskset -c 0 perf stat --repeat 50 -e instructions,cycles,branches
bash -c "for ((i=0;i<5;i++)); do $(dirname $0)/pipe-test 20000; done"'
There's a speedup for all situations:
instructions cycles branches
-------------------------------------------------------------------------
Intel Westmere
base 806611770 745895590 146765378
+jumplabel 803090165 (-0.44%) 713381840 (-4.36%) 144561130
AMD Barcelona
base 824657415 740055589 148855354
+jumplabel 821056910 (-0.44%) 737558389 (-0.34%) 146635229
Signed-off-by: Paul Turner <pjt@google.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/20111108042736.560831357@google.com
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'init')
0 files changed, 0 insertions, 0 deletions