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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:Davidlohr Bueso <dbueso@suse.de> Tested-by:
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