Messages in this thread | | | Subject | Re: [PATCH] perf stat: Show percore counts in per CPU output | From | "Jin, Yao" <> | Date | Mon, 10 Feb 2020 21:46:46 +0800 |
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On 2/10/2020 9:28 PM, Jiri Olsa wrote: > On Thu, Feb 06, 2020 at 09:56:13AM +0800, Jin Yao wrote: >> We have supported the event modifier "percore" which sums up the >> event counts for all hardware threads in a core and show the counts >> per core. >> >> For example, >> >> # perf stat -e cpu/event=cpu-cycles,percore/ -a -A -- sleep 1 >> >> Performance counter stats for 'system wide': >> >> S0-D0-C0 395,072 cpu/event=cpu-cycles,percore/ >> S0-D0-C1 851,248 cpu/event=cpu-cycles,percore/ >> S0-D0-C2 954,226 cpu/event=cpu-cycles,percore/ >> S0-D0-C3 1,233,659 cpu/event=cpu-cycles,percore/ >> >> This patch provides a new option "--percore-show-thread". It is >> used with event modifier "percore" together to sum up the event counts >> for all hardware threads in a core but show the counts per hardware >> thread. >> >> For example, >> >> # perf stat -e cpu/event=cpu-cycles,percore/ -a -A --percore-show-thread -- sleep 1 >> >> Performance counter stats for 'system wide': >> >> CPU0 2,453,061 cpu/event=cpu-cycles,percore/ >> CPU1 1,823,921 cpu/event=cpu-cycles,percore/ >> CPU2 1,383,166 cpu/event=cpu-cycles,percore/ >> CPU3 1,102,652 cpu/event=cpu-cycles,percore/ >> CPU4 2,453,061 cpu/event=cpu-cycles,percore/ >> CPU5 1,823,921 cpu/event=cpu-cycles,percore/ >> CPU6 1,383,166 cpu/event=cpu-cycles,percore/ >> CPU7 1,102,652 cpu/event=cpu-cycles,percore/ > > I don't understand how is this different from -A output: > > # ./perf stat -e cpu/event=cpu-cycles/ -A > ^C > Performance counter stats for 'system wide': > > CPU0 56,847,497 cpu/event=cpu-cycles/ > CPU1 75,274,384 cpu/event=cpu-cycles/ > CPU2 63,866,342 cpu/event=cpu-cycles/ > CPU3 89,559,693 cpu/event=cpu-cycles/ > CPU4 74,761,132 cpu/event=cpu-cycles/ > CPU5 76,320,191 cpu/event=cpu-cycles/ > CPU6 55,100,175 cpu/event=cpu-cycles/ > CPU7 48,472,895 cpu/event=cpu-cycles/ > > 1.074800857 seconds time elapsed >
The results are different.
With --percore-show-thread, CPU0 and CPU4 have the same counts (CPU0 and CPU4 are siblings, e.g. 2,453,061 in my example). The value is sum of CPU0 + CPU4.
Without --percore-show-thread, CPU0 and CPU4 have their own counts.
> also the interval output is mangled: > > # ./perf stat -e cpu/event=cpu-cycles,percore/ -a -A --percore-show-thread -I 1000 > # time CPU counts unit events > 1.000177375 1.000177375 CPU0 138,483,540 cpu/event=cpu-cycles,percore/ > 1.000177375 1.000177375 CPU1 143,159,477 cpu/event=cpu-cycles,percore/ > 1.000177375 1.000177375 CPU2 177,554,642 cpu/event=cpu-cycles,percore/ > 1.000177375 1.000177375 CPU3 150,974,512 cpu/event=cpu-cycles,percore/ > 1.000177375 1.000177375 CPU4 138,483,540 cpu/event=cpu-cycles,percore/ > 1.000177375 1.000177375 CPU5 143,159,477 cpu/event=cpu-cycles,percore/ > 1.000177375 1.000177375 CPU6 177,554,642 cpu/event=cpu-cycles,percore/ > > jirka >
Sorry, why the interval output is mangled? It's expected that CPU0 and CPU4 have the same counts.
Thanks Jin Yao
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