On 2019/8/21 20:38, James Clark wrote: > Hi, > > I also had a look at this and had a question about the --spe option. > It seems that whatever options I give it, the output is the same: > > perf report > And > perf report --spe=t > > Both give the same result: > > # Samples: 4 of event 'llc-miss' > # Event count (approx.): 4 > # > # Children Self Command Shared Object Symbol > > # ........ ........ ....... ................. > .......................... > # > ... > # Samples: 0 of event 'tlb-miss' > # Event count (approx.): 0 > # > # Children Self Command Shared Object Symbol > # ........ ........ ....... ............. ...... > # > > # Samples: 83 of event 'branch-miss' > # Event count (approx.): 83 > # > # Children Self Command Shared Object Symbol > > # ........ ........ ....... ................. > ......................... > # > ... > > I would have expected it to not include the branch and LLC sections for the > second > command with --spe=t. >
Hi, Sorry, this should be a bug in my code. > And that leads me to another point. Does it make sense to have this option as > a post > processing step? SPE already has support for filtering events at collection > time with > the PMSFCR_EL1 register. > > Should we try to make the interface more like PEBS, where you specify which > events you > are interested in doing precise tracing on like this? > > perf record -e branch-misses:pp > > And then perf could use the modifier to configure SPE so that it only records > branch > misses? The benefits of this would be keeping the user interface for precise > tracing > similar between platforms. > Good suggestion. And I need to spend some time thinking about how to implement it. Thank you for your reply. Xiaojun. > Thanks > James > > On 02/08/2019 10:40, Tan Xiaojun wrote: >> The previous patch added support in "perf report" for some arm-spe >> events(llc-miss, tlb-miss, branch-miss). This patch adds their help >> instructions. >> >> Signed-off-by: Tan Xiaojun <tanxiao...@huawei.com> >> --- >> tools/perf/Documentation/perf-report.txt | 9 +++++++++ >> 1 file changed, 9 insertions(+) >> >> diff --git a/tools/perf/Documentation/perf-report.txt >> b/tools/perf/Documentation/perf-report.txt >> index 987261d..d998d4b 100644 >> --- a/tools/perf/Documentation/perf-report.txt >> +++ b/tools/perf/Documentation/perf-report.txt >> @@ -445,6 +445,15 @@ include::itrace.txt[] >> >> To disable decoding entirely, use --no-itrace. >> >> +--spe:: >> + Options for decoding arm-spe tracing data. The options are: >> + >> + l synthesize llc miss events >> + t synthesize tlb miss events >> + b synthesize branch miss events >> + >> + The default is all events i.e. the same as --spe=ltb >> + >> --full-source-path:: >> Show the full path for source files for srcline output. >> >>
