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authorDavid Ahern <dsa@cumulusnetworks.com>2016-11-29 10:15:45 -0700
committerArnaldo Carvalho de Melo <acme@redhat.com>2016-12-01 13:03:02 -0300
commit2a865bd8dddd44315c88bf922761e4fd3374d046 (patch)
tree778a7494562592245ec3ad31061537a6fc1c4fee /tools/perf/Documentation
parent853b74071110bed344bad1ca9d8de27731b1c574 (diff)
perf kmem: Add option to specify time window of interest
Add option to allow user to control analysis window. e.g., collect data for time window and analyze a segment of interest within that window. Committer notes: Testing it: # perf kmem record usleep 1 [ perf record: Woken up 0 times to write data ] [ perf record: Captured and wrote 1.540 MB perf.data (2049 samples) ] # perf evlist kmem:kmalloc kmem:kmalloc_node kmem:kfree kmem:kmem_cache_alloc kmem:kmem_cache_alloc_node kmem:kmem_cache_free # Tip: use 'perf evlist --trace-fields' to show fields for tracepoint events # # # Use 'perf script' to get a first approach, select a chunk for then using # # with 'perf kmem stat --time' # # perf script | tail -15 usleep 9889 [0] 20119.782088: kmem:kmem_cache_free: (selinux_file_free_security+0x27) call_site=ffffffffb936aa07 ptr=0xffff888a1df49fc0 perf 9888 [3] 20119.782088: kmem:kmem_cache_free: (jbd2_journal_stop+0x1a1) call_site=ffffffffb9334581 ptr=0xffff888bdf1a39c0 perf 9888 [3] 20119.782089: kmem:kmem_cache_alloc: (jbd2__journal_start+0x72) call_site=ffffffffb9333b42 ptr=0xffff888bdf1a39c0 bytes_req=48 bytes_alloc=48 gfp_flags=GFP_NOFS|__GFP_ZERO perf 9888 [3] 20119.782090: kmem:kmem_cache_free: (jbd2_journal_stop+0x1a1) call_site=ffffffffb9334581 ptr=0xffff888bdf1a39c0 perf 9888 [3] 20119.782090: kmem:kmem_cache_alloc: (jbd2__journal_start+0x72) call_site=ffffffffb9333b42 ptr=0xffff888bdf1a39c0 bytes_req=48 bytes_alloc=48 gfp_flags=GFP_NOFS|__GFP_ZERO usleep 9889 [0] 20119.782091: kmem:kmem_cache_alloc: (__sigqueue_alloc+0x4a) call_site=ffffffffb90ad33a ptr=0xffff8889f071f6e0 bytes_req=160 bytes_alloc=160 gfp_flags=GFP_ATOMIC|__GFP_NOTRACK perf 9888 [3] 20119.782091: kmem:kmem_cache_free: (jbd2_journal_stop+0x1a1) call_site=ffffffffb9334581 ptr=0xffff888bdf1a39c0 perf 9888 [3] 20119.782093: kmem:kmem_cache_free: (__sigqueue_free.part.17+0x33) call_site=ffffffffb90ad3f3 ptr=0xffff8889f071f6e0 perf 9888 [3] 20119.782098: kmem:kmem_cache_alloc: (jbd2__journal_start+0x72) call_site=ffffffffb9333b42 ptr=0xffff888bdf1a39c0 bytes_req=48 bytes_alloc=48 gfp_flags=GFP_NOFS|__GFP_ZERO perf 9888 [3] 20119.782098: kmem:kmem_cache_free: (jbd2_journal_stop+0x1a1) call_site=ffffffffb9334581 ptr=0xffff888bdf1a39c0 perf 9888 [3] 20119.782099: kmem:kmem_cache_alloc: (jbd2__journal_start+0x72) call_site=ffffffffb9333b42 ptr=0xffff888bdf1a39c0 bytes_req=48 bytes_alloc=48 gfp_flags=GFP_NOFS|__GFP_ZERO perf 9888 [3] 20119.782100: kmem:kmem_cache_alloc: (alloc_buffer_head+0x21) call_site=ffffffffb9287cc1 ptr=0xffff8889b12722d8 bytes_req=104 bytes_alloc=104 gfp_flags=GFP_NOFS|__GFP_ZERO perf 9888 [3] 20119.782101: kmem:kmem_cache_free: (jbd2_journal_stop+0x1a1) call_site=ffffffffb9334581 ptr=0xffff888bdf1a39c0 perf 9888 [3] 20119.782102: kmem:kmem_cache_alloc: (jbd2__journal_start+0x72) call_site=ffffffffb9333b42 ptr=0xffff888bdf1a39c0 bytes_req=48 bytes_alloc=48 gfp_flags=GFP_NOFS|__GFP_ZERO perf 9888 [3] 20119.782103: kmem:kmem_cache_free: (jbd2_journal_stop+0x1a1) call_site=ffffffffb9334581 ptr=0xffff888bdf1a39c0 # # # stats for the whole perf.data file, i.e. no interval specified # # perf kmem stat SUMMARY (SLAB allocator) ======================== Total bytes requested: 172,628 Total bytes allocated: 173,088 Total bytes freed: 161,280 Net total bytes allocated: 11,808 Total bytes wasted on internal fragmentation: 460 Internal fragmentation: 0.265761% Cross CPU allocations: 0/851 # # # stats for an end open interval, after a certain time: # # perf kmem stat --time 20119.782088, SUMMARY (SLAB allocator) ======================== Total bytes requested: 552 Total bytes allocated: 552 Total bytes freed: 448 Net total bytes allocated: 104 Total bytes wasted on internal fragmentation: 0 Internal fragmentation: 0.000000% Cross CPU allocations: 0/8 # Signed-off-by: David Ahern <dsahern@gmail.com> Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com> Acked-by: Namhyung Kim <namhyung@kernel.org> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/1480439746-42695-6-git-send-email-dsahern@gmail.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Diffstat (limited to 'tools/perf/Documentation')
-rw-r--r--tools/perf/Documentation/perf-kmem.txt7
1 files changed, 7 insertions, 0 deletions
diff --git a/tools/perf/Documentation/perf-kmem.txt b/tools/perf/Documentation/perf-kmem.txt
index ff0f433b3fce..479fc3261a50 100644
--- a/tools/perf/Documentation/perf-kmem.txt
+++ b/tools/perf/Documentation/perf-kmem.txt
@@ -61,6 +61,13 @@ OPTIONS
default, but this option shows live (currently allocated) pages
instead. (This option works with --page option only)
+--time::
+ Only analyze samples within given time window: <start>,<stop>. Times
+ have the format seconds.microseconds. If start is not given (i.e., time
+ string is ',x.y') then analysis starts at the beginning of the file. If
+ stop time is not given (i.e, time string is 'x.y,') then analysis goes
+ to end of file.
+
SEE ALSO
--------
linkperf:perf-record[1]