mainlining shenanigans
'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> |
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arch | ||
block | ||
certs | ||
crypto | ||
Documentation | ||
drivers | ||
firmware | ||
fs | ||
include | ||
init | ||
ipc | ||
kernel | ||
lib | ||
LICENSES | ||
mm | ||
net | ||
samples | ||
scripts | ||
security | ||
sound | ||
tools | ||
usr | ||
virt | ||
.clang-format | ||
.cocciconfig | ||
.get_maintainer.ignore | ||
.gitattributes | ||
.gitignore | ||
.mailmap | ||
COPYING | ||
CREDITS | ||
Kbuild | ||
Kconfig | ||
MAINTAINERS | ||
Makefile | ||
README |
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.