On 11/29/2018 9:27 PM, Ingo Molnar wrote:
* Jin Yao <yao....@linux.intel.com> wrote:
Add explanations for new columns "IPC" and "IPC coverage" in perf
documentation.
Signed-off-by: Jin Yao <yao....@linux.intel.com>
---
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 474a494..e5a32f3 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 performance bottleneck when the function is
+ executed, such as, memory access bottleneck. If a function has high
overhead
+ and low IPC, it's worth further analysis for performance optimization.
Thank you for adding this!
Just a few small nits:
s/may be performance bottleneck
/may be a performance bottleneck
s/such as, memory access bottleneck
/such as a memory access bottleneck
s/it's worth further analysis for performance optimization.
/it's worth further analyzing it to optimize its performance.
?
Other than that:
Reviewed-by: Ingo Molnar <mi...@kernel.org>
Ingo
Thanks Ingo!
I will add these fixes in v5.
Thanks
Jin Yao
