[lkml]   [2018]   [Dec]   [6]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
Messages in this thread
Patch in this message
Subject[PATCH 26/75] perf report: Documentation average IPC and IPC coverage
From: Jin Yao <>

Add explanations for new columns "IPC" and "IPC coverage" in perf

Update the description according to Ingo's comments.

Signed-off-by: Jin Yao <>
Reviewed-by: Ingo Molnar <>
Reviewed-by: Jiri Olsa <>
Cc: Alexander Shishkin <>
Cc: Andi Kleen <>
Cc: Kan Liang <>
Cc: Peter Zijlstra <>
Signed-off-by: Arnaldo Carvalho de Melo <>
tools/perf/Documentation/perf-report.txt | 8 ++++++++
1 file changed, 8 insertions(+)

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.
 \ /
  Last update: 2018-12-06 22:33    [W:0.028 / U:4.584 seconds]
©2003-2018 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site