perf data: Allow to use stdio functions for pipe mode
When perf data is in a pipe, it reads each event separately using
read(2) syscall. This is a huge performance bottleneck when
processing large data like in perf inject. Also perf inject needs to
use write(2) syscall for the output.
So convert it to use buffer I/O functions in stdio library for pipe
data. This makes inject-build-id bench time drops from 20ms to 8ms.
$ perf bench internals inject-build-id
# Running 'internals/inject-build-id' benchmark:
Average build-id injection took: 8.074 msec (+- 0.013 msec)
Average time per event: 0.792 usec (+- 0.001 usec)
Average memory usage: 8328 KB (+- 0 KB)
Average build-id-all injection took: 5.490 msec (+- 0.008 msec)
Average time per event: 0.538 usec (+- 0.001 usec)
Average memory usage: 7563 KB (+- 0 KB)
This patch enables it just for perf inject when used with pipe (it's a
default behavior). Maybe we could do it for perf record and/or report
later..
Committer testing:
Before:
$ perf stat -r 5 perf bench internals inject-build-id
# Running 'internals/inject-build-id' benchmark:
Average build-id injection took: 13.605 msec (+- 0.064 msec)
Average time per event: 1.334 usec (+- 0.006 usec)
Average memory usage: 12220 KB (+- 7 KB)
Average build-id-all injection took: 11.458 msec (+- 0.058 msec)
Average time per event: 1.123 usec (+- 0.006 usec)
Average memory usage: 11546 KB (+- 8 KB)
# Running 'internals/inject-build-id' benchmark:
Average build-id injection took: 13.673 msec (+- 0.057 msec)
Average time per event: 1.341 usec (+- 0.006 usec)
Average memory usage: 12508 KB (+- 8 KB)
Average build-id-all injection took: 11.437 msec (+- 0.046 msec)
Average time per event: 1.121 usec (+- 0.004 usec)
Average memory usage: 11812 KB (+- 7 KB)
# Running 'internals/inject-build-id' benchmark:
Average build-id injection took: 13.641 msec (+- 0.069 msec)
Average time per event: 1.337 usec (+- 0.007 usec)
Average memory usage: 12302 KB (+- 8 KB)
Average build-id-all injection took: 10.820 msec (+- 0.106 msec)
Average time per event: 1.061 usec (+- 0.010 usec)
Average memory usage: 11616 KB (+- 7 KB)
# Running 'internals/inject-build-id' benchmark:
Average build-id injection took: 13.379 msec (+- 0.074 msec)
Average time per event: 1.312 usec (+- 0.007 usec)
Average memory usage: 12334 KB (+- 8 KB)
Average build-id-all injection took: 11.288 msec (+- 0.071 msec)
Average time per event: 1.107 usec (+- 0.007 usec)
Average memory usage: 11657 KB (+- 8 KB)
# Running 'internals/inject-build-id' benchmark:
Average build-id injection took: 13.534 msec (+- 0.058 msec)
Average time per event: 1.327 usec (+- 0.006 usec)
Average memory usage: 12264 KB (+- 8 KB)
Average build-id-all injection took: 11.557 msec (+- 0.076 msec)
Average time per event: 1.133 usec (+- 0.007 usec)
Average memory usage: 11593 KB (+- 8 KB)
Performance counter stats for 'perf bench internals inject-build-id' (5 runs):
4,060.05 msec task-clock:u # 1.566 CPUs utilized ( +- 0.65% )
0 context-switches:u # 0.000 K/sec
0 cpu-migrations:u # 0.000 K/sec
101,888 page-faults:u # 0.025 M/sec ( +- 0.12% )
3,745,833,163 cycles:u # 0.923 GHz ( +- 0.10% ) (83.22%)
194,346,613 stalled-cycles-frontend:u # 5.19% frontend cycles idle ( +- 0.57% ) (83.30%)
708,495,034 stalled-cycles-backend:u # 18.91% backend cycles idle ( +- 0.48% ) (83.48%)
5,629,328,628 instructions:u # 1.50 insn per cycle
# 0.13 stalled cycles per insn ( +- 0.21% ) (83.57%)
1,236,697,927 branches:u # 304.602 M/sec ( +- 0.16% ) (83.44%)
17,564,877 branch-misses:u # 1.42% of all branches ( +- 0.23% ) (82.99%)
2.5934 +- 0.0128 seconds time elapsed ( +- 0.49% )
$
After:
$ perf stat -r 5 perf bench internals inject-build-id
# Running 'internals/inject-build-id' benchmark:
Average build-id injection took: 8.560 msec (+- 0.125 msec)
Average time per event: 0.839 usec (+- 0.012 usec)
Average memory usage: 12520 KB (+- 8 KB)
Average build-id-all injection took: 5.789 msec (+- 0.054 msec)
Average time per event: 0.568 usec (+- 0.005 usec)
Average memory usage: 11919 KB (+- 9 KB)
# Running 'internals/inject-build-id' benchmark:
Average build-id injection took: 8.639 msec (+- 0.111 msec)
Average time per event: 0.847 usec (+- 0.011 usec)
Average memory usage: 12732 KB (+- 8 KB)
Average build-id-all injection took: 5.647 msec (+- 0.069 msec)
Average time per event: 0.554 usec (+- 0.007 usec)
Average memory usage: 12093 KB (+- 7 KB)
# Running 'internals/inject-build-id' benchmark:
Average build-id injection took: 8.551 msec (+- 0.096 msec)
Average time per event: 0.838 usec (+- 0.009 usec)
Average memory usage: 12739 KB (+- 8 KB)
Average build-id-all injection took: 5.617 msec (+- 0.061 msec)
Average time per event: 0.551 usec (+- 0.006 usec)
Average memory usage: 12105 KB (+- 7 KB)
# Running 'internals/inject-build-id' benchmark:
Average build-id injection took: 8.403 msec (+- 0.097 msec)
Average time per event: 0.824 usec (+- 0.010 usec)
Average memory usage: 12770 KB (+- 8 KB)
Average build-id-all injection took: 5.611 msec (+- 0.085 msec)
Average time per event: 0.550 usec (+- 0.008 usec)
Average memory usage: 12134 KB (+- 8 KB)
# Running 'internals/inject-build-id' benchmark:
Average build-id injection took: 8.518 msec (+- 0.102 msec)
Average time per event: 0.835 usec (+- 0.010 usec)
Average memory usage: 12518 KB (+- 10 KB)
Average build-id-all injection took: 5.503 msec (+- 0.073 msec)
Average time per event: 0.540 usec (+- 0.007 usec)
Average memory usage: 11882 KB (+- 8 KB)
Performance counter stats for 'perf bench internals inject-build-id' (5 runs):
2,394.88 msec task-clock:u # 1.577 CPUs utilized ( +- 0.83% )
0 context-switches:u # 0.000 K/sec
0 cpu-migrations:u # 0.000 K/sec
103,181 page-faults:u # 0.043 M/sec ( +- 0.11% )
3,548,172,030 cycles:u # 1.482 GHz ( +- 0.30% ) (83.26%)
81,537,700 stalled-cycles-frontend:u # 2.30% frontend cycles idle ( +- 1.54% ) (83.24%)
876,631,544 stalled-cycles-backend:u # 24.71% backend cycles idle ( +- 1.14% ) (83.45%)
5,960,361,707 instructions:u # 1.68 insn per cycle
# 0.15 stalled cycles per insn ( +- 0.27% ) (83.26%)
1,269,413,491 branches:u # 530.054 M/sec ( +- 0.10% ) (83.48%)
11,372,453 branch-misses:u # 0.90% of all branches ( +- 0.52% ) (83.31%)
1.51874 +- 0.00642 seconds time elapsed ( +- 0.42% )
$
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Acked-by: Jiri Olsa <jolsa@redhat.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lore.kernel.org/lkml/20201030054742.87740-1-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
5 files changed