Re: [PATCH v4 4/4] perf report: Documentation average IPC and IPC coverage
On 11/29/2018 9:27 PM, Ingo Molnar wrote: * Jin Yao wrote: Add explanations for new columns "IPC" and "IPC coverage" in perf documentation. Signed-off-by: Jin Yao --- 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 Ingo Thanks Ingo! I will add these fixes in v5. Thanks Jin Yao
Re: [PATCH v4 4/4] perf report: Documentation average IPC and IPC coverage
On 11/29/2018 9:27 PM, Ingo Molnar wrote: * Jin Yao wrote: Add explanations for new columns "IPC" and "IPC coverage" in perf documentation. Signed-off-by: Jin Yao --- 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 Ingo Thanks Ingo! I will add these fixes in v5. Thanks Jin Yao
Re: [PATCH v4 4/4] perf report: Documentation average IPC and IPC coverage
* Jin Yao wrote: > Add explanations for new columns "IPC" and "IPC coverage" in perf > documentation. > > Signed-off-by: Jin Yao > --- > 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 Ingo
Re: [PATCH v4 4/4] perf report: Documentation average IPC and IPC coverage
* Jin Yao wrote: > Add explanations for new columns "IPC" and "IPC coverage" in perf > documentation. > > Signed-off-by: Jin Yao > --- > 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 Ingo
