From ea57c4f5203d82c7844c54cdef54e972cf4e9d1f Mon Sep 17 00:00:00 2001 From: Ingo Molnar Date: Sun, 13 Sep 2009 18:15:54 +0200 Subject: perf tools: Implement counter output multiplexing Finish the -M/--multiplex option implementation: - separate it out from group_fd - correctly set it via the ioctl and dont mmap counters that are multiplexed - modify the perf record event loop to deal with buffer-less counters. - remove the -g option from perf sched record - account for unordered events in perf sched latency - (add -f to perf sched record to ease measurements) - skip idle threads (pid==0) in latency output The result is better latency output by 'perf sched latency': ----------------------------------------------------------------------------------- Task | Runtime ms | Switches | Average delay ms | Maximum delay ms | ----------------------------------------------------------------------------------- ksoftirqd/8 | 0.071 ms | 2 | avg: 0.458 ms | max: 0.913 ms | at-spi-registry | 0.609 ms | 19 | avg: 0.013 ms | max: 0.023 ms | perf | 3.316 ms | 16 | avg: 0.013 ms | max: 0.054 ms | Xorg | 0.392 ms | 19 | avg: 0.011 ms | max: 0.018 ms | sleep | 0.537 ms | 2 | avg: 0.009 ms | max: 0.009 ms | ----------------------------------------------------------------------------------- TOTAL: | 4.925 ms | 58 | --------------------------------------------- Cc: Peter Zijlstra Cc: Mike Galbraith Cc: Paul Mackerras Cc: Arnaldo Carvalho de Melo Cc: Frederic Weisbecker LKML-Reference: Signed-off-by: Ingo Molnar --- tools/perf/builtin-record.c | 43 ++++++++++++++++++++++++++----------------- 1 file changed, 26 insertions(+), 17 deletions(-) (limited to 'tools/perf/builtin-record.c') diff --git a/tools/perf/builtin-record.c b/tools/perf/builtin-record.c index 79f99db..5f3127e 100644 --- a/tools/perf/builtin-record.c +++ b/tools/perf/builtin-record.c @@ -49,6 +49,7 @@ static int inherit_stat = 0; static int no_samples = 0; static int sample_address = 0; static int multiplex = 0; +static int multiplex_fd = -1; static long samples; static struct timeval last_read; @@ -471,23 +472,29 @@ try_again: */ if (group && group_fd == -1) group_fd = fd[nr_cpu][counter]; + if (multiplex && multiplex_fd == -1) + multiplex_fd = fd[nr_cpu][counter]; - event_array[nr_poll].fd = fd[nr_cpu][counter]; - event_array[nr_poll].events = POLLIN; - nr_poll++; - - mmap_array[nr_cpu][counter].counter = counter; - mmap_array[nr_cpu][counter].prev = 0; - mmap_array[nr_cpu][counter].mask = mmap_pages*page_size - 1; - mmap_array[nr_cpu][counter].base = mmap(NULL, (mmap_pages+1)*page_size, - PROT_READ|PROT_WRITE, MAP_SHARED, fd[nr_cpu][counter], 0); - if (mmap_array[nr_cpu][counter].base == MAP_FAILED) { - error("failed to mmap with %d (%s)\n", errno, strerror(errno)); - exit(-1); - } + if (multiplex && fd[nr_cpu][counter] != multiplex_fd) { + int ret; - if (multiplex && fd[nr_cpu][counter] != group_fd) - ioctl(fd[nr_cpu][counter], PERF_COUNTER_IOC_SET_OUTPUT, group_fd); + ret = ioctl(fd[nr_cpu][counter], PERF_COUNTER_IOC_SET_OUTPUT, multiplex_fd); + assert(ret != -1); + } else { + event_array[nr_poll].fd = fd[nr_cpu][counter]; + event_array[nr_poll].events = POLLIN; + nr_poll++; + + mmap_array[nr_cpu][counter].counter = counter; + mmap_array[nr_cpu][counter].prev = 0; + mmap_array[nr_cpu][counter].mask = mmap_pages*page_size - 1; + mmap_array[nr_cpu][counter].base = mmap(NULL, (mmap_pages+1)*page_size, + PROT_READ|PROT_WRITE, MAP_SHARED, fd[nr_cpu][counter], 0); + if (mmap_array[nr_cpu][counter].base == MAP_FAILED) { + error("failed to mmap with %d (%s)\n", errno, strerror(errno)); + exit(-1); + } + } ioctl(fd[nr_cpu][counter], PERF_COUNTER_IOC_ENABLE); } @@ -618,8 +625,10 @@ static int __cmd_record(int argc, const char **argv) int hits = samples; for (i = 0; i < nr_cpu; i++) { - for (counter = 0; counter < nr_counters; counter++) - mmap_read(&mmap_array[i][counter]); + for (counter = 0; counter < nr_counters; counter++) { + if (mmap_array[i][counter].base) + mmap_read(&mmap_array[i][counter]); + } } if (hits == samples) { -- cgit v1.1