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author | Jin Yao <yao.jin@linux.intel.com> | 2018-11-30 16:54:57 +0300 |
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committer | Arnaldo Carvalho de Melo <acme@redhat.com> | 2018-12-17 20:55:49 +0300 |
commit | 239ca3e78609378a1ed5d9db1c7db629a71c2857 (patch) | |
tree | ebe60ef9ee58be125f1490454da0690e23c5315d | |
parent | ec6ae74fe8f00c7df018628ada9d33190de72efa (diff) | |
download | linux-239ca3e78609378a1ed5d9db1c7db629a71c2857.tar.xz |
perf report: Documentation average IPC and IPC coverage
Add explanations for new columns "IPC" and "IPC coverage" in perf
documentation.
v5:
---
Update the description according to Ingo's comments.
Signed-off-by: Jin Yao <yao.jin@linux.intel.com>
Reviewed-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Jiri Olsa <jolsa@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1543586097-27632-5-git-send-email-yao.jin@linux.intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
-rw-r--r-- | tools/perf/Documentation/perf-report.txt | 8 |
1 files changed, 8 insertions, 0 deletions
diff --git a/tools/perf/Documentation/perf-report.txt b/tools/perf/Documentation/perf-report.txt index 474a4941f65d..ed2bf37ab132 100644 --- a/tools/perf/Documentation/perf-report.txt +++ b/tools/perf/Documentation/perf-report.txt @@ -126,6 +126,14 @@ OPTIONS And default sort keys are changed to comm, dso_from, symbol_from, dso_to and symbol_to, see '--branch-stack'. + When the sort key symbol is specified, columns "IPC" and "IPC Coverage" + are enabled automatically. Column "IPC" reports the average IPC per function + and column "IPC coverage" reports the percentage of instructions with + sampled IPC in this function. IPC means Instruction Per Cycle. If it's low, + it indicates there may be a performance bottleneck when the function is + executed, such as a memory access bottleneck. If a function has high overhead + and low IPC, it's worth further analyzing it to optimize its performance. + If the --mem-mode option is used, the following sort keys are also available (incompatible with --branch-stack): symbol_daddr, dso_daddr, locked, tlb, mem, snoop, dcacheline. |