Reputation: 1236

Can Linux perf compare per - thread performance?

I know perf can profile a single process or single thread use perf stat -p tid/pid or perf top -p tid/pid.

But I want to profile per-thread in a process, getting separate results for each and every thread. I want to compare events to see which thread is high consumption. Can perf do this? If not, which tools can?

Upvotes: 6

Answers (4)

pan

Reputation: 81

Use '-t' option to specify thread ID. For example:

perf stat -t 11111

Upvotes: 1

osgx

Reputation: 94465

There was proposed patch to add --per-thread option to perf stat (and with interval mode -I 1000 it is possible to see current counters every second for every thread ): https://lwn.net/Articles/649001/ "perf stat: Introduce --per-thread option" From: Jiri Olsa, Date: Tue, 23 Jun 2015

adding the possibility to display stat data per thread.

Allowing following commands and output:

$ perf stat -e cycles,instructions --per-thread -p 30190,30242 ^C Performance counter stats for process id '30190,30242':

           cat-30190                     0      cycles
           yes-30242         3,842,525,421      cycles
           cat-30190                     0      instructions
           yes-30242        10,370,817,010      instructions

     1.143155657 seconds time elapsed

Also works under interval mode:

$ perf stat -e cycles,instructions --per-thread -p 30190,30242 -I 1000

#           time             comm-pid                  counts   unit events
   1.000073435              cat-30190                89,058      cycles
   1.000073435              yes-30242         3,360,786,902      cycles                     (100.00%)
   1.000073435              cat-30190                14,066      instructions
   1.000073435              yes-30242         9,069,937,462      instructions
   2.000204830              cat-30190                     0      cycles
   2.000204830              yes-30242         3,351,667,626      cycles
   2.000204830              cat-30190                     0      instructions
   2.000204830              yes-30242         9,045,796,885      instructions   
  ^C
   2.771286639              cat-30190                     0      cycles
   2.771286639              yes-30242         2,593,884,166      cycles
   2.771286639              cat-30190                     0      instructions
   2.771286639              yes-30242         7,001,171,191      instructions

Available in here:
git://git.kernel.org/pub/scm/linux/kernel/git/jolsa/perf.git
perf/per_thread

Upvotes: 4