• Davidlohr Bueso's avatar
    perf bench: Add epoll_ctl(2) benchmark · 231457ec
    Davidlohr Bueso authored
    Benchmark the various operations allowed for epoll_ctl(2).  The idea is
    to concurrently stress a single epoll instance doing add/mod/del
    operations.
    
    Committer testing:
    
      # perf bench epoll ctl
      # Running 'epoll/ctl' benchmark:
      Run summary [PID 20344]: 4 threads doing epoll_ctl ops 64 file-descriptors for 8 secs.
    
      [thread  0] fdmap: 0x21a46b0 ... 0x21a47ac [ add: 1680960 ops; mod: 1680960 ops; del: 1680960 ops ]
      [thread  1] fdmap: 0x21a4960 ... 0x21a4a5c [ add: 1685440 ops; mod: 1685440 ops; del: 1685440 ops ]
      [thread  2] fdmap: 0x21a4c10 ... 0x21a4d0c [ add: 1674368 ops; mod: 1674368 ops; del: 1674368 ops ]
      [thread  3] fdmap: 0x21a4ec0 ... 0x21a4fbc [ add: 1677568 ops; mod: 1677568 ops; del: 1677568 ops ]
    
      Averaged 1679584 ADD operations (+- 0.14%)
      Averaged 1679584 MOD operations (+- 0.14%)
      Averaged 1679584 DEL operations (+- 0.14%)
      #
    
    Lets measure those calls with 'perf trace' to get a glympse at what this
    benchmark is doing in terms of syscalls:
    
      # perf trace -m32768 -s perf bench epoll ctl
      # Running 'epoll/ctl' benchmark:
      Run summary [PID 20405]: 4 threads doing epoll_ctl ops 64 file-descriptors for 8 secs.
    
      [thread  0] fdmap: 0x21764e0 ... 0x21765dc [ add: 1100480 ops; mod: 1100480 ops; del: 1100480 ops ]
      [thread  1] fdmap: 0x2176790 ... 0x217688c [ add: 1250176 ops; mod: 1250176 ops; del: 1250176 ops ]
      [thread  2] fdmap: 0x2176a40 ... 0x2176b3c [ add: 1022464 ops; mod: 1022464 ops; del: 1022464 ops ]
      [thread  3] fdmap: 0x2176cf0 ... 0x2176dec [ add: 705472 ops; mod: 705472 ops; del: 705472 ops ]
    
      Averaged 1019648 ADD operations (+- 11.27%)
      Averaged 1019648 MOD operations (+- 11.27%)
      Averaged 1019648 DEL operations (+- 11.27%)
    
      Summary of events:
    
      epoll-ctl (20405), 1264 events, 0.0%
    
       syscall            calls    total       min       avg       max      stddev
                                   (msec)    (msec)    (msec)    (msec)        (%)
       --------------- -------- --------- --------- --------- ---------     ------
       eventfd2             256     9.514     0.001     0.037     5.243     68.00%
       clone                  4     1.245     0.204     0.311     0.531     24.13%
       mprotect              66     0.345     0.002     0.005     0.021      7.43%
       openat                45     0.313     0.004     0.007     0.073     21.93%
       mmap                  88     0.302     0.002     0.003     0.013      5.02%
       futex                  4     0.160     0.002     0.040     0.140     83.43%
       sched_setaffinity      4     0.124     0.005     0.031     0.070     49.39%
       read                  44     0.103     0.001     0.002     0.013     15.54%
       fstat                 40     0.052     0.001     0.001     0.003      5.43%
       close                 39     0.039     0.001     0.001     0.001      1.48%
       stat                   9     0.034     0.003     0.004     0.006      7.30%
       access                 3     0.023     0.007     0.008     0.008      4.25%
       open                   2     0.021     0.008     0.011     0.013     22.60%
       getdents               4     0.019     0.001     0.005     0.009     37.15%
       write                  2     0.013     0.004     0.007     0.009     38.48%
       munmap                 1     0.010     0.010     0.010     0.010      0.00%
       brk                    3     0.006     0.001     0.002     0.003     26.34%
       rt_sigprocmask         2     0.004     0.001     0.002     0.003     43.95%
       rt_sigaction           3     0.004     0.001     0.001     0.002     16.07%
       prlimit64              3     0.004     0.001     0.001     0.001      5.39%
       prctl                  1     0.003     0.003     0.003     0.003      0.00%
       epoll_create           1     0.003     0.003     0.003     0.003      0.00%
       lseek                  2     0.002     0.001     0.001     0.001     11.42%
       sched_getaffinity        1     0.002     0.002     0.002     0.002      0.00%
       arch_prctl             1     0.002     0.002     0.002     0.002      0.00%
       set_tid_address        1     0.001     0.001     0.001     0.001      0.00%
       getpid                 1     0.001     0.001     0.001     0.001      0.00%
       set_robust_list        1     0.001     0.001     0.001     0.001      0.00%
       execve                 1     0.000     0.000     0.000     0.000      0.00%
    
     epoll-ctl (20406), 1245480 events, 14.6%
    
       syscall            calls    total       min       avg       max      stddev
                                   (msec)    (msec)    (msec)    (msec)        (%)
       --------------- -------- --------- --------- --------- ---------     ------
       epoll_ctl         619511  1034.927     0.001     0.002     6.691      0.67%
       nanosleep           3226   616.114     0.006     0.191    10.376      7.57%
       futex                  2    11.336     0.002     5.668    11.334     99.97%
       set_robust_list        1     0.001     0.001     0.001     0.001      0.00%
       clone                  1     0.000     0.000     0.000     0.000      0.00%
    
     epoll-ctl (20407), 1243151 events, 14.5%
    
       syscall            calls    total       min       avg       max      stddev
                                   (msec)    (msec)    (msec)    (msec)        (%)
       --------------- -------- --------- --------- --------- ---------     ------
       epoll_ctl         618350  1042.181     0.001     0.002     2.512      0.40%
       nanosleep           3220   366.261     0.012     0.114    18.162      9.59%
       futex                  4     5.463     0.001     1.366     5.427     99.12%
       set_robust_list        1     0.002     0.002     0.002     0.002      0.00%
    
     epoll-ctl (20408), 1801690 events, 21.1%
    
       syscall            calls    total       min       avg       max      stddev
                                   (msec)    (msec)    (msec)    (msec)        (%)
       --------------- -------- --------- --------- --------- ---------     ------
       epoll_ctl         896174  1540.581     0.001     0.002     6.987      0.74%
       nanosleep           4667   783.393     0.006     0.168    10.419      7.10%
       futex                  2     4.682     0.002     2.341     4.681     99.93%
       set_robust_list        1     0.002     0.002     0.002     0.002      0.00%
       clone                  1     0.000     0.000     0.000     0.000      0.00%
    
     epoll-ctl (20409), 4254890 events, 49.8%
    
       syscall            calls    total       min       avg       max      stddev
                                   (msec)    (msec)    (msec)    (msec)        (%)
       --------------- -------- --------- --------- --------- ---------     ------
       epoll_ctl        2116416  3768.097     0.001     0.002     9.956      0.41%
       nanosleep          11023  1141.778     0.006     0.104     9.447      4.95%
       futex                  3     0.037     0.002     0.012     0.029     70.50%
       set_robust_list        1     0.008     0.008     0.008     0.008      0.00%
       madvise                1     0.005     0.005     0.005     0.005      0.00%
       clone                  1     0.000     0.000     0.000     0.000      0.00%
      #
    
    Committer notes:
    
    Fix build on fedora:24-x-ARC-uClibc, debian:experimental-x-mips,
    debian:experimental-x-mipsel, ubuntu:16.04-x-arm and ubuntu:16.04-x-powerpc
    
        CC       /tmp/build/perf/bench/epoll-ctl.o
      bench/epoll-ctl.c: In function 'init_fdmaps':
      bench/epoll-ctl.c:214:16: error: comparison between signed and unsigned integer expressions [-Werror=sign-compare]
        for (i = 0; i < nfds; i+=inc) {
                      ^
      bench/epoll-ctl.c: In function 'bench_epoll_ctl':
      bench/epoll-ctl.c:377:16: error: comparison between signed and unsigned integer expressions [-Werror=sign-compare]
        for (i = 0; i < nthreads; i++) {
                      ^
      bench/epoll-ctl.c:388:16: error: comparison between signed and unsigned integer expressions [-Werror=sign-compare]
        for (i = 0; i < nthreads; i++) {
                      ^
      cc1: all warnings being treated as errors
    Signed-off-by: default avatarDavidlohr Bueso <dbueso@suse.de>
    Tested-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
    Cc: Andrew Morton <akpm@linux-foundation.org>
    Cc: Davidlohr Bueso <dbueso@suse.de>
    Cc: Jason Baron <jbaron@akamai.com>
    Link: http://lkml.kernel.org/r/20181106152226.20883-3-dave@stgolabs.net
    [ Use inttypes.h to print rlim_t fields, fixing the build on Alpine Linux / musl libc ]
    [ Check if eventfd() is available, i.e. if HAVE_EVENTFD is defined ]
    Signed-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
    231457ec
epoll-ctl.c 9.57 KB