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590ac60d8a
'perf report' has supported the displaying of LBR stats (such as cycles,
predicted%) in callchain entry.
For example:
$ perf report --branch-history --stdio
--1.01%--intel_idle mwait.h:29
intel_idle cpufeature.h:164 (cycles:5)
intel_idle cpufeature.h:164 (predicted:76.4%)
intel_idle mwait.h:102 (cycles:41)
intel_idle current.h:15
While 'perf top' doesn't support that.
For example:
$ perf top -a -b --call-graph branch
- 13.86% 0.23% [kernel] [k] __x86_indirect_thunk_rax
- 13.65% __x86_indirect_thunk_rax
+ 1.69% do_syscall_64
+ 1.68% do_select
+ 1.41% ktime_get
+ 0.70% __schedule
+ 0.62% do_sys_poll
0.58% __x86_indirect_thunk_rax
Actually it's very easy to enable this feature in 'perf top'.
With this patch, the result is:
$ perf top -a -b --call-graph branch
$ - 13.58% 0.00% [kernel] [k] __x86_indirect_thunk_rax
$ - 13.57% __x86_indirect_thunk_rax (predicted:93.9%)
$ + 1.78% do_select (cycles:2)
$ + 1.68% perf_pmu_disable.part.99 (cycles:1)
$ + 1.45% ___sys_recvmsg (cycles:25)
$ + 0.81% unix_stream_sendmsg (cycles:18)
$ + 0.80% ktime_get (cycles:400)
$ 0.58% pick_next_task_fair (cycles:47)
$ + 0.56% i915_request_retire (cycles:2)
$ + 0.52% do_sys_poll (cycles:4)
Signed-off-by: Jin Yao <yao.jin@linux.intel.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1540983995-20462-1-git-send-email-yao.jin@linux.intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.