Commits
Namhyung Kim committed 7ed5d6e28a0
perf report: Fix percent display in callchains on --stdio
When there's only a single callchain, perf doesn't print its percentage
in front of the symbols. This is because it assumes that the percentage
is same as parents. But if a percent limit is applied, it's possible
that there are actually a couple of child nodes but only one of them is
shown. In this case it should display the percent to prevent
misunderstanding of its percentage is same as the parent's.
For example, let's see the following callchain.
$ perf report -s comm --percent-limit 0.01 --stdio
...
9.95% swapper
|
|--7.57%--intel_idle
| cpuidle_enter_state
| cpuidle_enter
| call_cpuidle
| cpu_startup_entry
| |
| |--4.89%--start_secondary
| |
| --2.68%--rest_init
| start_kernel
| x86_64_start_reservations
| x86_64_start_kernel
|
|--0.15%--__schedule
| |
| |--0.13%--schedule
| | schedule_preempt_disable
| | cpu_startup_entry
| | |
| | |--0.09%--start_secondary
| | |
| | --0.04%--rest_init
| | start_kernel
| | x86_64_start_reservations
| | x86_64_start_kernel
| |
| --0.01%--schedule_preempt_disabled
| cpu_startup_entry
...
Current code omits the percent if 'intel_idle' becomes the only node
when percent limit is set to 0.5%, its percent is not 9.95% but users
will assume it incorrectly.
Before:
$ perf report --percent-limit 0.5 --stdio
...
9.95% swapper
|
---intel_idle
cpuidle_enter_state
cpuidle_enter
call_cpuidle
cpu_startup_entry
|
|--4.89%--start_secondary
|
--2.68%--rest_init
start_kernel
x86_64_start_reservations
x86_64_start_kernel
After:
$ perf report --percent-limit 0.5 --stdio
...
9.95% swapper
|
--7.57%--intel_idle
cpuidle_enter_state
cpuidle_enter
call_cpuidle
cpu_startup_entry
|
|--4.89%--start_secondary
|
--2.68%--rest_init
start_kernel
x86_64_start_reservations
x86_64_start_kernel
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/r/1453909257-26015-7-git-send-email-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>