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Paul Turner authored
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.comSigned-off-by:
Ingo Molnar <mingo@elte.hu>
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