Subject: [RFC 0/4] perf tool: Adding ratios support Newsgroups: gmane.linux.kernel Date: Tuesday 15th January 2013 13:39:50 UTC (over 3 years ago) hi, adding support to predefine event ratios formulas so they could be used easily in perf. The formulas are handed in the config file with following format: set { events = {cycles,instructions,branch-instructions}:u cpi { formula = cycles / instructions desc = cycles per instruction } branch-rate { formula = branch-instructions / instructions desc = branch rate } } The 'set' defines set of counter that share same events. Each 'set' defines: events - event string that would go into stat/record -e option counters - any number of counters based on above events Each counter (cpi/branch-rate) defines formula - formula with that produce the counter number event names and numbers could be used desc - text description of the counter The formula can currently contain any event from the set::events plus any number (int). There'll be support in future for outside values runtime and other if needed. My current thinking is to have generic formulas file(s) for architectural events and add arch-specific ones once when we have the support for non-architectural events (already sent RFC, v2 is on its way..). Example: With following formula.conf config file: --- cpi { events = {cycles,instructions}:u CPI { formula = cycles / instructions desc = cycles per instruction } } branch { events = {instructions,branch-instructions,branch-misses}:u branch-rate { formula = branch-instructions / instructions desc = branch rate } branch-miss-rate { formula = branch-misses / instructions desc = branch misprediction rate } branch-miss-ratio{ formula = branch-misses / branch-instructions desc = branch misprediction ratio } } --- You'll get following result: $ perf stat -f formula.conf:branch kill usage: kill [ -s signal | -p ] [ -a ] pid ... kill -l [ signal ] Performance counter stats for 'kill': 184,195 instructions # 0.00 insns per cycle 40,907 branch-instructions 4,815 branch-misses # 11.77% of all branches 0.000655767 seconds time elapsed 0.22208529 branch-rate # branch rate 0.02614077 branch-miss-rate # branch misprediction rate 0.11770602 branch-miss-ratio # branch misprediction ratio $ perf stat -f formula.conf:cpi kill usage: kill [ -s signal | -p ] [ -a ] pid ... kill -l [ signal ] Performance counter stats for 'kill': 356,635 cycles # 0.000 GHz 187,191 instructions # 0.52 insns per cycle 0.001907600 seconds time elapsed 1.90519309 CPI # cycles per instruction Available also at: git://git.kernel.org/pub/scm/linux/kernel/git/jolsa/linux.git perf/ratios2 thanks for any ideas, jirka Cc: Arnaldo Carvalho de Melo |
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