linux/tools
He Kuang 40f20e5074 perf script: Show call graphs when 1st event doesn't have it but some other has
There's a display inconsistency when there are multiple tracepoint
events, some of which have the 'call-graph' config option set but the
first one hasn't, i.e. the whole logic for call graph processing is
enabled only if the first tracepoint event has call-graph set.

For instance, if we record signal_deliver with call-graph and
signal_generate without:

  $ perf record -g -a -e signal:signal_deliver -e signal:signal_generate/call-graph=no/

  [ perf record: Captured and wrote 0.017 MB perf.data (2 samples) ]

  $ perf script

  kworker/u2:1    13 [000]  6563.875949: signal:signal_generate: sig=2 errno=0 code=128 comm=perf pid=1313 grp=1 res=0 ff61cc __send_signal+0x3ec ([kernel.kallsyms])
  perf  1313 [000]  6563.877584:  signal:signal_deliver: sig=2 errno=0 code=128 sa_handler=43115e sa_flags=14000000
              7ffff314 get_signal+0x80007f0023a4 ([kernel.kallsyms])
              7fffe358 do_signal+0x80007f002028 ([kernel.kallsyms])
              7fffa5e8 exit_to_usermode_loop+0x80007f002053 ([kernel.kallsyms])
              ...

Then we exchange the order of these two events in commandline, and keep
signal_generate without call-graph.

  $ perf record -g -a -e signal:signal_generate/call-graph=no/ -e signal:signal_deliver

  [ perf record: Captured and wrote 0.017 MB perf.data (2 samples) ]

  $ perf script

    kworker/u2:2  1314 [000]  6933.353060: signal:signal_generate: sig=2 errno=0 code=128 comm=perf pid=1321 grp=1 res=0
            perf  1321 [000]  6933.353872:  signal:signal_deliver: sig=2 errno=0 code=128 sa_handler=43115e sa_flags=14000000

This time, the callchain of the event signal_deliver disappeared. The
problem is caused by that perf only checks for the first evsel in evlist
and decides if callchain should be printed.

This patch traverses all evsels in evlist to see if any of them have
callchains, and shows the right result:

  $ perf script

  kworker/u2:2  1314 [000]  6933.353060: signal:signal_generate: sig=2 errno=0 code=128 comm=perf pid=1321 grp=1 res=0 ff61cc __send_signal+0x3ec ([kernel.kallsyms])
  perf  1321 [000]  6933.353872:  signal:signal_deliver: sig=2 errno=0 code=128 sa_handler=43115e sa_flags=14000000
              7ffff314 get_signal+0x80007f0023a4 ([kernel.kallsyms])
              7fffe358 do_signal+0x80007f002028 ([kernel.kallsyms])
              7fffa5e8 exit_to_usermode_loop+0x80007f002053 ([kernel.kallsyms])
              ...

Signed-off-by: He Kuang <hekuang@huawei.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/r/1463374279-97209-1-git-send-email-hekuang@huawei.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2016-06-03 14:53:46 -03:00
..
arch tools include: Add basic atomic.h implementation from the kernel sources 2015-05-08 16:11:05 -03:00
build perf probe: Check if dwarf_getlocations() is available 2016-05-12 11:26:59 -03:00
cgroup
firewire
gpio gpio: present the consumer of a line to userspace 2016-02-25 21:07:23 +01:00
hv tools/hv: Use include/uapi with __EXPORTED_HEADERS__ 2016-02-07 21:34:12 -08:00
iio iio: generic_buffer: be helpful about enabling channels 2015-08-16 10:51:26 +01:00
include Merge branch 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2016-03-24 10:02:14 -07:00
laptop/freefall Move freefall program from Documentation/ to tools/ 2015-06-08 16:42:07 -06:00
lguest tools/lguest: Force disable tboot and APM 2016-04-22 10:29:03 +02:00
lib tools lib api: Respect CROSS_COMPILE for the linker 2016-06-03 14:53:46 -03:00
net tools: bpf_jit_disasm: check for klogctl failure 2016-05-08 23:32:59 -04:00
nfsd
objtool objtool: Detect falling through to the next function 2016-04-16 11:14:17 +02:00
perf perf script: Show call graphs when 1st event doesn't have it but some other has 2016-06-03 14:53:46 -03:00
power Merge branches 'pm-core', 'powercap' and 'pm-tools' 2016-04-08 21:46:56 +02:00
scripts tools: Move utilities.mak from perf to tools/scripts/ 2016-03-18 13:57:20 -03:00
spi spi: spidev_test: Fix typo in error message 2015-12-08 17:58:56 +00:00
testing Merge branch 'x86-asm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2016-05-16 15:15:17 -07:00
thermal/tmon tools/thermal: tmon: use pkg-config also for CFLAGS 2015-10-10 11:32:31 +08:00
time
usb usb: patches for v4.4 merge window 2015-10-22 17:19:33 -07:00
virtio virtio_ring: Support DMA APIs 2016-03-02 17:01:57 +02:00
vm tools/vm/page-types.c: avoid memset() in walk_pfn() when count == 1 2016-03-17 15:09:34 -07:00
Makefile tools build: Fix perf_clean target 2016-04-25 17:59:36 -03:00