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authorIngo Molnar <mingo@elte.hu>2009-09-13 18:15:54 +0200
committerIngo Molnar <mingo@elte.hu>2009-09-14 15:45:11 +0200
commitea57c4f5203d82c7844c54cdef54e972cf4e9d1f (patch)
tree13eb76a07480adbfe1bcabd25cde7cdd12907ddb /tools/perf/builtin-record.c
parentaa1ab9d26ae9fe2566a9036e3cb83e7d555b3987 (diff)
downloadlinux-2.6.34-ux500-ea57c4f5203d82c7844c54cdef54e972cf4e9d1f.tar.gz
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 <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Paul Mackerras <paulus@samba.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> LKML-Reference: <new-submission> Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'tools/perf/builtin-record.c')
-rw-r--r--tools/perf/builtin-record.c43
1 files changed, 26 insertions, 17 deletions
diff --git a/tools/perf/builtin-record.c b/tools/perf/builtin-record.c
index 79f99dba5be..5f3127e7a61 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) {