perf stat: Add stalled cycles to the default output
The new default output looks like this: Performance counter stats for './loop_1b_instructions': 236.010686 task-clock # 0.996 CPUs utilized 0 context-switches # 0.000 M/sec 0 CPU-migrations # 0.000 M/sec 99 page-faults # 0.000 M/sec 756,487,646 cycles # 3.205 GHz 354,938,996 stalled-cycles # 46.92% of all cycles are idle 1,001,403,797 instructions # 1.32 insns per cycle # 0.35 stalled cycles per insn 100,279,773 branches # 424.895 M/sec 12,646 branch-misses # 0.013 % of all branches 0.236902540 seconds time elapsed We dropped cache-refs and cache-misses and added stalled-cycles - this is a more generic "how well utilized is the CPU" metric. If the stalled-cycles ratio is too high then more specific measurements can be taken to figure out the source of the inefficiency. Acked-by: NPeter Zijlstra <a.p.zijlstra@chello.nl> Acked-by: NArnaldo Carvalho de Melo <acme@redhat.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Link: http://lkml.kernel.org/n/tip-pbpl2l4mn797s69bclfpwkwn@git.kernel.orgSigned-off-by: NIngo Molnar <mingo@elte.hu>
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