linux/tools/perf/Documentation/perf-kmem.txt

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perf-kmem(1)
============
NAME
----
perf kmem: Analyze page allocator events also The perf kmem command records and analyze kernel memory allocation only for SLAB objects. This patch implement a simple page allocator analyzer using kmem:mm_page_alloc and kmem:mm_page_free events. It adds two new options of --slab and --page. The --slab option is for analyzing SLAB allocator and that's what perf kmem currently does. The new --page option enables page allocator events and analyze kernel memory usage in page unit. Currently, 'stat --alloc' subcommand is implemented only. If none of these --slab nor --page is specified, --slab is implied. First run 'perf kmem record' to generate a suitable perf.data file: # perf kmem record --page sleep 5 Then run 'perf kmem stat' to postprocess the perf.data file: # perf kmem stat --page --alloc --line 10 ------------------------------------------------------------------------------- PFN | Total alloc (KB) | Hits | Order | Mig.type | GFP flags ------------------------------------------------------------------------------- 4045014 | 16 | 1 | 2 | RECLAIM | 00285250 4143980 | 16 | 1 | 2 | RECLAIM | 00285250 3938658 | 16 | 1 | 2 | RECLAIM | 00285250 4045400 | 16 | 1 | 2 | RECLAIM | 00285250 3568708 | 16 | 1 | 2 | RECLAIM | 00285250 3729824 | 16 | 1 | 2 | RECLAIM | 00285250 3657210 | 16 | 1 | 2 | RECLAIM | 00285250 4120750 | 16 | 1 | 2 | RECLAIM | 00285250 3678850 | 16 | 1 | 2 | RECLAIM | 00285250 3693874 | 16 | 1 | 2 | RECLAIM | 00285250 ... | ... | ... | ... | ... | ... ------------------------------------------------------------------------------- SUMMARY (page allocator) ======================== Total allocation requests : 44,260 [ 177,256 KB ] Total free requests : 117 [ 468 KB ] Total alloc+freed requests : 49 [ 196 KB ] Total alloc-only requests : 44,211 [ 177,060 KB ] Total free-only requests : 68 [ 272 KB ] Total allocation failures : 0 [ 0 KB ] Order Unmovable Reclaimable Movable Reserved CMA/Isolated ----- ------------ ------------ ------------ ------------ ------------ 0 32 . 44,210 . . 1 . . . . . 2 . 18 . . . 3 . . . . . 4 . . . . . 5 . . . . . 6 . . . . . 7 . . . . . 8 . . . . . 9 . . . . . 10 . . . . . Signed-off-by: Namhyung Kim <namhyung@kernel.org> Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: David Ahern <dsahern@gmail.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Joonsoo Kim <js1304@gmail.com> Cc: Minchan Kim <minchan@kernel.org> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: linux-mm@kvack.org Link: http://lkml.kernel.org/r/1428298576-9785-4-git-send-email-namhyung@kernel.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2015-04-06 13:36:10 +08:00
perf-kmem - Tool to trace/measure kernel memory properties
SYNOPSIS
--------
[verse]
'perf kmem' {record|stat} [<options>]
DESCRIPTION
-----------
There are two variants of perf kmem:
'perf kmem record <command>' to record the kmem events
of an arbitrary workload.
'perf kmem stat' to report kernel memory statistics.
OPTIONS
-------
-i <file>::
--input=<file>::
Select the input file (default: perf.data unless stdin is a fifo)
-v::
--verbose::
Be more verbose. (show symbol address, etc)
--caller::
Show per-callsite statistics
--alloc::
Show per-allocation statistics
-s <key[,key2...]>::
--sort=<key[,key2...]>::
perf kmem: Support sort keys on page analysis Add new sort keys for page: page, order, migtype, gfp - existing 'bytes', 'hit' and 'callsite' sort keys also work for page. Note that -s/--sort option should be preceded by either of --slab or --page option to determine where the sort keys applies. Now it properly groups and sorts allocation stats - so same page/caller with different order/migtype/gfp will be printed on a different line. # perf kmem stat --page --caller -l 10 -s order,hit ----------------------------------------------------------------------------- Total alloc (KB) | Hits | Order | Mig.type | GFP flags | Callsite ----------------------------------------------------------------------------- 64 | 4 | 2 | RECLAIM | 00285250 | new_slab 50,144 | 12,536 | 0 | MOVABLE | 0102005a | __page_cache_alloc 52 | 13 | 0 | UNMOVABL | 002084d0 | pte_alloc_one 40 | 10 | 0 | MOVABLE | 000280da | handle_mm_fault 28 | 7 | 0 | UNMOVABL | 000000d0 | __pollwait 20 | 5 | 0 | MOVABLE | 000200da | do_wp_page 20 | 5 | 0 | MOVABLE | 000200da | do_cow_fault 16 | 4 | 0 | UNMOVABL | 00000200 | __tlb_remove_page 16 | 4 | 0 | UNMOVABL | 000084d0 | __pmd_alloc 8 | 2 | 0 | UNMOVABL | 000084d0 | __pud_alloc ... | ... | ... | ... | ... | ... ----------------------------------------------------------------------------- Signed-off-by: Namhyung Kim <namhyung@kernel.org> Acked-by: Pekka Enberg <penberg@kernel.org> Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: David Ahern <dsahern@gmail.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Joonsoo Kim <js1304@gmail.com> Cc: Minchan Kim <minchan@kernel.org> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: linux-mm@kvack.org Link: http://lkml.kernel.org/r/1429592107-1807-3-git-send-email-namhyung@kernel.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2015-04-21 12:55:03 +08:00
Sort the output (default: 'frag,hit,bytes' for slab and 'bytes,hit'
for page). Available sort keys are 'ptr, callsite, bytes, hit,
pingpong, frag' for slab and 'page, callsite, bytes, hit, order,
migtype, gfp' for page. This option should be preceded by one of the
mode selection options - i.e. --slab, --page, --alloc and/or --caller.
-l <num>::
--line=<num>::
Print n lines only
--raw-ip::
Print raw ip instead of symbol
perf kmem: Analyze page allocator events also The perf kmem command records and analyze kernel memory allocation only for SLAB objects. This patch implement a simple page allocator analyzer using kmem:mm_page_alloc and kmem:mm_page_free events. It adds two new options of --slab and --page. The --slab option is for analyzing SLAB allocator and that's what perf kmem currently does. The new --page option enables page allocator events and analyze kernel memory usage in page unit. Currently, 'stat --alloc' subcommand is implemented only. If none of these --slab nor --page is specified, --slab is implied. First run 'perf kmem record' to generate a suitable perf.data file: # perf kmem record --page sleep 5 Then run 'perf kmem stat' to postprocess the perf.data file: # perf kmem stat --page --alloc --line 10 ------------------------------------------------------------------------------- PFN | Total alloc (KB) | Hits | Order | Mig.type | GFP flags ------------------------------------------------------------------------------- 4045014 | 16 | 1 | 2 | RECLAIM | 00285250 4143980 | 16 | 1 | 2 | RECLAIM | 00285250 3938658 | 16 | 1 | 2 | RECLAIM | 00285250 4045400 | 16 | 1 | 2 | RECLAIM | 00285250 3568708 | 16 | 1 | 2 | RECLAIM | 00285250 3729824 | 16 | 1 | 2 | RECLAIM | 00285250 3657210 | 16 | 1 | 2 | RECLAIM | 00285250 4120750 | 16 | 1 | 2 | RECLAIM | 00285250 3678850 | 16 | 1 | 2 | RECLAIM | 00285250 3693874 | 16 | 1 | 2 | RECLAIM | 00285250 ... | ... | ... | ... | ... | ... ------------------------------------------------------------------------------- SUMMARY (page allocator) ======================== Total allocation requests : 44,260 [ 177,256 KB ] Total free requests : 117 [ 468 KB ] Total alloc+freed requests : 49 [ 196 KB ] Total alloc-only requests : 44,211 [ 177,060 KB ] Total free-only requests : 68 [ 272 KB ] Total allocation failures : 0 [ 0 KB ] Order Unmovable Reclaimable Movable Reserved CMA/Isolated ----- ------------ ------------ ------------ ------------ ------------ 0 32 . 44,210 . . 1 . . . . . 2 . 18 . . . 3 . . . . . 4 . . . . . 5 . . . . . 6 . . . . . 7 . . . . . 8 . . . . . 9 . . . . . 10 . . . . . Signed-off-by: Namhyung Kim <namhyung@kernel.org> Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: David Ahern <dsahern@gmail.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Joonsoo Kim <js1304@gmail.com> Cc: Minchan Kim <minchan@kernel.org> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: linux-mm@kvack.org Link: http://lkml.kernel.org/r/1428298576-9785-4-git-send-email-namhyung@kernel.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2015-04-06 13:36:10 +08:00
--slab::
Analyze SLAB allocator events.
--page::
Analyze page allocator events
perf kmem: Add --live option for current allocation stat Currently 'perf kmem stat --page' shows total (page) allocation stat by default, but sometimes one might want to see live (total alloc-only) requests/pages only. The new --live option does this by subtracting freed allocation from the stat. E.g.: # perf kmem stat --page SUMMARY (page allocator) ======================== Total allocation requests : 988,858 [ 4,045,368 KB ] Total free requests : 886,484 [ 3,624,996 KB ] Total alloc+freed requests : 885,969 [ 3,622,628 KB ] Total alloc-only requests : 102,889 [ 422,740 KB ] Total free-only requests : 515 [ 2,368 KB ] Total allocation failures : 0 [ 0 KB ] Order Unmovable Reclaimable Movable Reserved CMA/Isolated ----- ------------ ------------ ------------ ------------ ------------ 0 172,173 3,083 806,686 . . 1 284 . . . . 2 6,124 58 . . . 3 114 335 . . . 4 . . . . . 5 . . . . . 6 . . . . . 7 . . . . . 8 . . . . . 9 . . 1 . . 10 . . . . . # perf kmem stat --page --live SUMMARY (page allocator) ======================== Total allocation requests : 988,858 [ 4,045,368 KB ] Total free requests : 886,484 [ 3,624,996 KB ] Total alloc+freed requests : 885,969 [ 3,622,628 KB ] Total alloc-only requests : 102,889 [ 422,740 KB ] Total free-only requests : 515 [ 2,368 KB ] Total allocation failures : 0 [ 0 KB ] Order Unmovable Reclaimable Movable Reserved CMA/Isolated ----- ------------ ------------ ------------ ------------ ------------ 0 2,214 3,025 97,156 . . 1 59 . . . . 2 19 58 . . . 3 23 335 . . . 4 . . . . . 5 . . . . . 6 . . . . . 7 . . . . . 8 . . . . . 9 . . . . . 10 . . . . . # Signed-off-by: Namhyung Kim <namhyung@kernel.org> Acked-by: Pekka Enberg <penberg@kernel.org> Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: David Ahern <dsahern@gmail.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Joonsoo Kim <js1304@gmail.com> Cc: Minchan Kim <minchan@kernel.org> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: linux-mm@kvack.org Link: http://lkml.kernel.org/r/1429592107-1807-4-git-send-email-namhyung@kernel.org [ Added examples to the changeset log ] Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2015-04-21 12:55:04 +08:00
--live::
Show live page stat. The perf kmem shows total allocation stat by
default, but this option shows live (currently allocated) pages
instead. (This option works with --page option only)
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>
2016-11-30 01:15:45 +08:00
--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]