Messages in this thread | | | Date | Thu, 5 Nov 2015 17:51:01 -0300 | From | Arnaldo Carvalho de Melo <> | Subject | Re: [PATCH 02/25] perf stat record: Add record command |
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Em Thu, Nov 05, 2015 at 03:40:46PM +0100, Jiri Olsa escreveu: > Add 'perf stat record' command support. It creates simple > (header only) perf.data file ATM. > > The record command could be specified anywhere among stat > options. All stat command options are valid for stat record > command with '-o' option exception. If specified for record > command it denotes the perf data file name. > > Tested-by: Kan Liang <kan.liang@intel.com> > Link: http://lkml.kernel.org/n/tip-0av5yfkwyywwgoiali88w4hi@git.kernel.org > Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Still stopping here:
[acme@zoo linux]$ rm -f perf.data [acme@zoo linux]$ perf stat record usleep 1
Performance counter stats for 'usleep 1':
0.621181 task-clock (msec) # 0.455 CPUs utilized 1 context-switches # 0.002 M/sec 0 cpu-migrations # 0.000 K/sec 54 page-faults # 0.087 M/sec 917,006 cycles # 1.476 GHz 611,746 stalled-cycles-frontend # 66.71% frontend cycles idle <not supported> stalled-cycles-backend 654,410 instructions # 0.71 insns per cycle # 0.93 stalled cycles per insn 132,653 branches # 213.550 M/sec 7,432 branch-misses # 5.60% of all branches
0.001365369 seconds time elapsed
[acme@zoo linux]$ ls -la perf.data -rw-------. 1 acme acme 1384 Nov 5 17:42 perf.data [acme@zoo linux]$ perf evlist WARNING: The perf.data file's data size field is 0 which is unexpected. Was the 'perf record' command properly terminated? non matching sample_type[acme@zoo linux]$
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When we pass one event it gets a bit better:
[acme@zoo linux]$ rm -f perf.data [acme@zoo linux]$ perf stat -e cycles record usleep 1
Performance counter stats for 'usleep 1':
1,056,818 cycles
0.000715850 seconds time elapsed
[acme@zoo linux]$ ls -la perf.data -rw-------. 1 acme acme 232 Nov 5 17:44 perf.data [acme@zoo linux]$ perf evlist WARNING: The perf.data file's data size field is 0 which is unexpected. Was the 'perf record' command properly terminated? cycles [acme@zoo linux]$
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In the second case it almost works, modulo that warning.
I think that what we need to achieve is for older tools to be able to, with a file produced by 'perf stat record', to show this:
[root@zoo ~]# perf report --no-header --stdio Error: The perf.data file has no samples! # To display the perf.data header info, please use --header/--header-only options. # [root@zoo ~]#
I.e. the file should look like one that is produced by this command, purposely to not create any sample:
# perf record -e syscalls:sys_enter_accept usleep 1 [ perf record: Woken up 1 times to write data ] [ perf record: Captured and wrote 0.018 MB perf.data ]
I applied the first patch and added it to that perf/stat branch.
- Arnaldo
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