Re: perf, tools: Refactor and support interval and CSV metrics

From: Jiri Olsa
Date: Fri Jan 22 2016 - 05:10:17 EST


On Tue, Jan 19, 2016 at 06:26:43PM -0800, Andi Kleen wrote:
> [v5: Fix mainly bisect problems. No regressions introduced by one
> patch and fixed again later. Some minor fixes in addition]
> [v6: Fix running/noise printing patch.]
> [v7: Reorder and merge two patches to avoid a bisect hole where unsupported was
> printed as 0]
> [v8: Minor fixes for review feedback. See changelog in patches.]
> [v9: Fix newline bug. Add support for -A for --metric-only]
>
> Currently perf stat does not support printing computed metrics for interval (-I xxx)
> or CSV (-x,) mode. For example IPC or TSX metrics over time are quite useful to know.
>
> This patch implements them. The main obstacle was that the
> metrics printing was all open coded all over the metrics computation code.
> The second patch refactors the metrics printing to work through call backs that
> can be more easily changed. This also cleans up the metrics printing significantly.
> The indentation is now handled through printf, no more need to manually count spaces.
>
> Then based on that it implements metrics printing for CSV and interval mode,
> and finally a --metric-only mode.
>
> Example output:
>
> % perf stat -I1000 -a sleep 1
> # time counts unit events metric multiplex
> 1.001301370 12020.049593 task-clock (msec) (100.00%)
> 1.001301370 3,952 context-switches # 0.329 K/sec (100.00%)
> 1.001301370 69 cpu-migrations # 0.006 K/sec (100.00%)
> 1.001301370 76 page-faults # 0.006 K/sec
> 1.001301370 386,582,789 cycles # 0.032 GHz (100.00%)
> 1.001301370 716,441,544 stalled-cycles-frontend # 185.33% frontend cycles idle (100.00%)
> 1.001301370 <not supported> stalled-cycles-backend
> 1.001301370 101,751,678 instructions # 0.26 insn per cycle
> 1.001301370 # 7.04 stalled cycles per insn (100.00%)
> 1.001301370 20,914,692 branches # 1.740 M/sec (100.00%)
> 1.001301370 1,943,630 branch-misses # 9.29% of all branches
>
> CSV mode
>
> % perf stat -x, -I1000 -a sleep 1
> 1.000852081,12016.143006,,task-clock
> 1.000852081,4457,,context-switches,12015168277,100.00,0.371,K/sec
> 1.000852081,50,,cpu-migrations,12014024424,100.00,0.004,K/sec
> 1.000852081,76,,page-faults,12013076716,100.00,0.006,K/sec
> 1.000852081,515854373,,cycles,12011235336,100.00,0.043,GHz
> 1.000852081,1030742150,,stalled-cycles-frontend,12010984057,100.00,199.81,frontend cycles idle
> 1.000852081,<not supported>,,stalled-cycles-backend,0,100.00
> 1.000852081,116782495,,instructions,12011130729,100.00,0.23,insn per cycle
> 1.000852081,,,,12011130729,100.00,8.83,stalled cycles per insn
> 1.000852081,23748237,,branches,12010745125,100.00,1.976,M/sec
> 1.000852081,1976560,,branch-misses,12010501884,100.00,8.32,of all branches
>
> Available in
> git://git.kernel.org/pub/scm/linux/kernel/git/ak/linux-misc-2.6 perf/stat-metrics-13

this looks like great test candidate for the testing
suite Michael is working on.. CC-ed

thanks,
jirka