kernel/linux.git/tools/perf/Documentation, branch v2.6.38

perf record: Add "nodelay" mode, disabled by default

2011-01-13T13:38:44+00:00

Sometimes there is a need to use perf in "live-log" mode. The problem is, for seldom events, actual info output is largely delayed because perf-record reads sample data in whole pages. So for such scenarious, add flag for perf-record to go in "nodelay" mode. To track e.g. what's going on in icmp_rcv while ping is running Use it with something like this: (1) $ perf probe -L icmp_rcv | grep -U8 '^ *43\>' goto error; } 38 if (!pskb_pull(skb, sizeof(*icmph))) goto error; icmph = icmp_hdr(skb); 43 ICMPMSGIN_INC_STATS_BH(net, icmph->type); /* * 18 is the highest 'known' ICMP type. Anything else is a mystery * * RFC 1122: 3.2.2 Unknown ICMP messages types MUST be silently * discarded. */ 50 if (icmph->type > NR_ICMP_TYPES) goto error; $ perf probe icmp_rcv:43 'type=icmph->type' (2) $ cat trace-icmp.py [...] def trace_begin(): print "in trace_begin" def trace_end(): print "in trace_end" def probe__icmp_rcv(event_name, context, common_cpu, common_secs, common_nsecs, common_pid, common_comm, __probe_ip, type): print_header(event_name, common_cpu, common_secs, common_nsecs, common_pid, common_comm) print "__probe_ip=%u, type=%u\n" % \ (__probe_ip, type), [...] (3) $ perf record -a -D -e probe:icmp_rcv -o - | \ perf script -i - -s trace-icmp.py Thanks to Peter Zijlstra for pointing how to do it. Cc: Arnaldo Carvalho de Melo Cc: Frederic Weisbecker Cc: Ingo Molnar , Mike Galbraith Cc: Paul Mackerras Cc: Peter Zijlstra Cc: Stephane Eranian Cc: Tom Zanussi LKML-Reference: <20110112140613.GA11698@tugrik.mns.mnsspb.ru> Signed-off-by: Kirill Smelkov Signed-off-by: Arnaldo Carvalho de Melo

perf probe: Fix line range description since a single file is allowed

2010-12-21T18:20:12+00:00

$ perf-probe -L sched.c is currently allowed but not documented. Cc: Masami Hiramatsu LKML-Reference: <1292854685-8230-5-git-send-email-fbuihuu@gmail.com> Signed-off-by: Franck Bui-Huu Signed-off-by: Arnaldo Carvalho de Melo

perf symbols: Add symfs option for off-box analysis using specified tree

2010-12-21T22:17:51+00:00

The symfs argument allows analysis of perf.data file using a locally accessible filesystem tree with debug symbols - e.g., tree created during image builds, sshfs mount, loop mounted KVM disk images, USB keys, initrds, etc. Anything with an OS tree can be analyzed from anywhere without the need to populate a local data store with build-ids. Commiter notes: o Fixed up symfs="/" variants handling. o prefixed DSO__ORIG_GUEST_KMODULE case with symfs too, avoiding use of files outside the symfs directory. LKML-Reference: <1291926427-28846-1-git-send-email-daahern@cisco.com> Signed-off-by: David Ahern Signed-off-by: Arnaldo Carvalho de Melo

perf report: Allow user to specify path to kallsyms file

2010-12-09T13:07:07+00:00

This is useful for analyzing a perf data file on a different system than the one data was collected on and still include symbols from loaded kernel modules in the output. Commiter note: Updated the man page accordingly. LKML-Reference: <1291775986-16475-1-git-send-email-daahern@cisco.com> Signed-off-by: David Ahern Signed-off-by: Arnaldo Carvalho de Melo

perf tools: Ask for ID PERF_SAMPLE_ info on all PERF_RECORD_ events

2010-12-05T01:08:40+00:00

So that we can use -T == --timestamp, asking for PERF_SAMPLE_TIME: $ perf record -aT $ perf report -D | grep PERF_RECORD_ 3 5951915425 0x47530 [0x58]: PERF_RECORD_SAMPLE(IP, 1): 16811/16811: 0xffffffff8138c1a2 period: 215979 cpu:3 3 5952026879 0x47588 [0x90]: PERF_RECORD_SAMPLE(IP, 1): 16811/16811: 0xffffffff810cb480 period: 215979 cpu:3 3 5952059959 0x47618 [0x38]: PERF_RECORD_FORK(6853:6853):(16811:16811) 3 5952138878 0x47650 [0x78]: PERF_RECORD_SAMPLE(IP, 1): 16811/16811: 0xffffffff811bac35 period: 431478 cpu:3 3 5952375068 0x476c8 [0x30]: PERF_RECORD_COMM: find:6853 3 5952395923 0x476f8 [0x50]: PERF_RECORD_MMAP 6853/6853: [0x400000(0x25000) @ 0]: /usr/bin/find 3 5952413756 0x47748 [0xa0]: PERF_RECORD_SAMPLE(IP, 1): 6853/6853: 0xffffffff810d080f period: 859332 cpu:3 3 5952419837 0x477e8 [0x58]: PERF_RECORD_MMAP 6853/6853: [0x3f44600000(0x21d000) @ 0]: /lib64/ld-2.5.so 3 5952437929 0x47840 [0x48]: PERF_RECORD_MMAP 6853/6853: [0x7fff7e1c9000(0x1000) @ 0x7fff7e1c9000]: [vdso] 3 5952570127 0x47888 [0x58]: PERF_RECORD_MMAP 6853/6853: [0x3f46200000(0x218000) @ 0]: /lib64/libselinux.so.1 3 5952623637 0x478e0 [0x58]: PERF_RECORD_MMAP 6853/6853: [0x3f44a00000(0x356000) @ 0]: /lib64/libc-2.5.so 3 5952675720 0x47938 [0x58]: PERF_RECORD_MMAP 6853/6853: [0x3f44e00000(0x204000) @ 0]: /lib64/libdl-2.5.so 3 5952710080 0x47990 [0x58]: PERF_RECORD_MMAP 6853/6853: [0x3f45a00000(0x246000) @ 0]: /lib64/libsepol.so.1 3 5952847802 0x479e8 [0x58]: PERF_RECORD_SAMPLE(IP, 1): 6853/6853: 0xffffffff813897f0 period: 1142536 cpu:3 First column is the cpu and the second the timestamp. That way we can investigate problems in the event stream. If the new perf binary is run on an older kernel, it will disable this feature automatically. Tested-by: Thomas Gleixner Reviewed-by: Thomas Gleixner Acked-by: Ian Munsie Acked-by: Thomas Gleixner Cc: Frédéric Weisbecker Cc: Ian Munsie Cc: Mike Galbraith Cc: Peter Zijlstra Cc: Paul Mackerras Cc: Stephane Eranian LKML-Reference: <1291318772-30880-5-git-send-email-acme@infradead.org> Signed-off-by: Arnaldo Carvalho de Melo

Merge branch 'perf/core' of git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux-2.6 into perf/core

2010-12-02T10:20:11+00:00

perf stat: Add csv-style output

2010-12-01T21:47:41+00:00

This patch adds an option (-x/--field-separator) to print counts using a CSV-style output. The user can pass a custom separator. This makes it very easy to import counts directly into your favorite spreadsheet without having to write scripts. Example: $ perf stat --field-separator=, -a -- sleep 1 4009.961740,task-clock-msecs 13,context-switches 2,CPU-migrations 189,page-faults 9596385684,cycles 3493659441,instructions 872897069,branches 41562,branch-misses 22424,cache-references 1289,cache-misses Works also in non-aggregated mode: $ perf stat -x , -a -A -- sleep 1 CPU0,1002.526168,task-clock-msecs CPU1,1002.528365,task-clock-msecs CPU2,1002.523360,task-clock-msecs CPU3,1002.519878,task-clock-msecs CPU0,1,context-switches CPU1,5,context-switches CPU2,5,context-switches CPU3,6,context-switches CPU0,0,CPU-migrations CPU1,1,CPU-migrations CPU2,0,CPU-migrations CPU3,1,CPU-migrations CPU0,2,page-faults CPU1,6,page-faults CPU2,9,page-faults CPU3,174,page-faults CPU0,2399439771,cycles CPU1,2380369063,cycles CPU2,2399142710,cycles CPU3,2373161192,cycles CPU0,872900618,instructions CPU1,873030960,instructions CPU2,872714525,instructions CPU3,874460580,instructions CPU0,221556839,branches CPU1,218134342,branches CPU2,218161730,branches CPU3,218284093,branches CPU0,18556,branch-misses CPU1,1449,branch-misses CPU2,3447,branch-misses CPU3,12714,branch-misses CPU0,8330,cache-references CPU1,313844,cache-references CPU2,47993728,cache-references CPU3,826481,cache-references CPU0,272,cache-misses CPU1,5360,cache-misses CPU2,1342193,cache-misses CPU3,13992,cache-misses This second version adds the ability to name a separator and uses field-separator as the long option to be consistent with perf report. Commiter note: Since we enabled --big-num by default in 201e0b0 and -x can't be used with it, we need to notice if the user explicitely enabled or disabled -B, add code to disable big_num if the user didn't explicitely set --big_num when -x is used. Cc: David S. Miller Cc: Frederik Weisbecker Cc: Ingo Molnar Cc: paulus@samba.org Cc: Peter Zijlstra Cc: Robert Richter LKML-Reference: <4cf68aa7.0fedd80a.5294.1203@mx.google.com> Signed-off-by: Stephane Eranian Signed-off-by: Arnaldo Carvalho de Melo

perf stat: Document missing options

2010-12-01T20:22:49+00:00

Cc: Ingo Molnar Cc: Paul Mackerras Cc: Peter Zijlstra LKML-Reference: <1291168642-11402-12-git-send-email-shawn.bohrer@gmail.com> Signed-off-by: Shawn Bohrer Signed-off-by: Arnaldo Carvalho de Melo

perf test: Fix spelling mistake in documentation

2010-12-01T20:22:49+00:00

Cc: Ingo Molnar Cc: Paul Mackerras Cc: Peter Zijlstra LKML-Reference: <1291168642-11402-13-git-send-email-shawn.bohrer@gmail.com> Signed-off-by: Shawn Bohrer Signed-off-by: Arnaldo Carvalho de Melo

perf trace: Document missing options

2010-12-01T20:22:48+00:00

Cc: Ingo Molnar Cc: Paul Mackerras Cc: Peter Zijlstra LKML-Reference: <1291168642-11402-15-git-send-email-shawn.bohrer@gmail.com> Signed-off-by: Shawn Bohrer Signed-off-by: Arnaldo Carvalho de Melo