kernel/tools/perf/Documentation, branch linux-5.1.y

perf intel-pt: Fix itrace defaults for perf script intel-pt documentation

2019-07-14T06:09:47Z

commit a2d8a1585e35444789c1c8cf7e2e51fb15589880 upstream. Fix intel-pt documentation to reflect the change of itrace defaults for perf script. Signed-off-by: Adrian Hunter Cc: Jiri Olsa Cc: stable@vger.kernel.org Fixes: 4eb068157121 ("perf script: Make itrace script default to all calls") Link: http://lkml.kernel.org/r/20190520113728.14389-4-adrian.hunter@intel.com Signed-off-by: Arnaldo Carvalho de Melo Signed-off-by: Greg Kroah-Hartman

perf config: Fix an error in the config template documentation

2019-03-19T19:52:04Z

The option 'sort-order' should be 'sort_order'. Signed-off-by: Changbin Du Reviewed-by: Jiri Olsa Cc: Alexei Starovoitov Cc: Daniel Borkmann Cc: Milian Wolff Cc: Namhyung Kim Cc: Peter Zijlstra Cc: Steven Rostedt (VMware) Fixes: 893c5c798be9 ("perf config: Show default report configuration in example and docs") Link: http://lkml.kernel.org/r/20190316080556.3075-5-changbin.du@gmail.com Signed-off-by: Arnaldo Carvalho de Melo

perf tools: Add doc about how to build perf with Asan and UBSan

2019-03-19T19:52:04Z

AddressSanitizer (or ASan) and UndefinedBehaviorSanitizer (or UBSan) are very useful tools to detect program bugs: - AddressSanitizer (or ASan) is a GCC feature that detects memory corruption bugs such as buffer overflows and memory leaks. - UndefinedBehaviorSanitizer (or UBSan) is a fast undefined behavior detector supported by GCC. UBSan detects undefined behaviors of programs at runtime. This patch adds a document about how to use them on perf. Later patches will fix some of the issues disclosed by them. Signed-off-by: Changbin Du Reviewed-by: Jiri Olsa Cc: Alexei Starovoitov Cc: Daniel Borkmann Cc: Namhyung Kim Cc: Peter Zijlstra Cc: Steven Rostedt (VMware) Link: http://lkml.kernel.org/r/20190316080556.3075-2-changbin.du@gmail.com [ Make some changes based on comments made by Jiri Olsa ] Signed-off-by: Arnaldo Carvalho de Melo

perf stat: Fix --no-scale

2019-03-19T19:52:03Z

The -c option to enable multiplex scaling has been useless for quite some time because scaling is default. It's only useful as --no-scale to disable scaling. But the non scaling code path has bitrotted and doesn't print anything because perf output code relies on value run/ena information. Also even when we don't want to scale a value it's still useful to show its multiplex percentage. This patch: - Fixes help and documentation to show --no-scale instead of -c - Removes -c, only keeps the long option because -c doesn't support negatives. - Enables running/enabled even with --no-scale - And fixes some other problems in the no-scale output. Before: $ perf stat --no-scale -e cycles true Performance counter stats for 'true': cycles 0.000984154 seconds time elapsed After: $ ./perf stat --no-scale -e cycles true Performance counter stats for 'true': 706,070 cycles 0.001219821 seconds time elapsed Signed-off-by: Andi Kleen Acked-by: Jiri Olsa Tested-by: Arnaldo Carvalho de Melo LPU-Reference: 20190314225002.30108-9-andi@firstfloor.org Link: https://lkml.kernel.org/n/tip-xggjvwcdaj2aqy8ib3i4b1g6@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo

perf script: Support relative time

2019-03-19T19:52:03Z

When comparing time stamps in 'perf script' traces it can be annoying to work with the full perf time stamps. Add a --reltime option that displays time stamps relative to the trace start to make it easier to read the traces. Note: not currently supported for --time. Report an error in this case. Before: % perf script swapper 0 [000] 245402.891216: 1 cycles:ppp: ffffffffa0068814 native_write_msr+0x4 ([kernel.kallsyms]) swapper 0 [000] 245402.891223: 1 cycles:ppp: ffffffffa0068814 native_write_msr+0x4 ([kernel.kallsyms]) swapper 0 [000] 245402.891227: 5 cycles:ppp: ffffffffa0068814 native_write_msr+0x4 ([kernel.kallsyms]) swapper 0 [000] 245402.891231: 41 cycles:ppp: ffffffffa0068816 native_write_msr+0x6 ([kernel.kallsyms]) swapper 0 [000] 245402.891235: 355 cycles:ppp: ffffffffa000dd51 intel_bts_enable_local+0x21 ([kernel.kallsyms]) swapper 0 [000] 245402.891239: 3084 cycles:ppp: ffffffffa0a0150a end_repeat_nmi+0x48 ([kernel.kallsyms]) After: % perf script --reltime swapper 0 [000] 0.000000: 1 cycles:ppp: ffffffffa0068814 native_write_msr+0x4 ([kernel.kallsyms]) swapper 0 [000] 0.000006: 1 cycles:ppp: ffffffffa0068814 native_write_msr+0x4 ([kernel.kallsyms]) swapper 0 [000] 0.000010: 5 cycles:ppp: ffffffffa0068814 native_write_msr+0x4 ([kernel.kallsyms]) swapper 0 [000] 0.000014: 41 cycles:ppp: ffffffffa0068816 native_write_msr+0x6 ([kernel.kallsyms]) swapper 0 [000] 0.000018: 355 cycles:ppp: ffffffffa000dd51 intel_bts_enable_local+0x21 ([kernel.kallsyms]) swapper 0 [000] 0.000022: 3084 cycles:ppp: ffffffffa0a0150a end_repeat_nmi+0x48 ([kernel.kallsyms]) Committer notes: Do not use 'time' as the name of a variable, as this breaks the build on older glibcs: cc1: warnings being treated as errors builtin-script.c: In function 'perf_sample__fprintf_start': builtin-script.c:691: warning: declaration of 'time' shadows a global declaration /usr/include/time.h:187: warning: shadowed declaration is here Signed-off-by: Andi Kleen Tested-by: Arnaldo Carvalho de Melo Acked-by: Jiri Olsa LPU-Reference: 20190314225002.30108-8-andi@firstfloor.org Link: https://lkml.kernel.org/n/tip-bpahyi6pr9r399mvihu65fvc@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo

perf record: Allow to limit number of reported perf.data files

2019-03-19T14:56:20Z

When doing long term recording and waiting for some event to snapshot on, we often only care about the last minute or so. The --switch-output command line option supports rotating the perf.data file when the size exceeds a threshold. But the disk would still be filled with unnecessary old files. Add a new option to only keep a number of rotated files, so that the disk space usage can be limited. Signed-off-by: Andi Kleen Acked-by: Jiri Olsa LPU-Reference: 20190314225002.30108-3-andi@firstfloor.org Link: https://lkml.kernel.org/n/tip-y5u2lik0ragt4vlktz6qc9ks@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo

perf tools report: Add custom scripts to script menu

2019-03-11T19:33:20Z

Add a way to define custom scripts through ~/.perfconfig, which are then added to the scripts menu. The scripts get the same arguments as 'perf script', in particular -i, --cpu, --tid. Signed-off-by: Andi Kleen Acked-by: Jiri Olsa Link: http://lkml.kernel.org/r/20190311144502.15423-10-andi@firstfloor.org Signed-off-by: Arnaldo Carvalho de Melo

perf tools: Add some new tips describing the new options

2019-03-11T19:33:19Z

Signed-off-by: Andi Kleen Acked-by: Jiri Olsa Link: http://lkml.kernel.org/r/20190311144502.15423-9-andi@firstfloor.org Signed-off-by: Arnaldo Carvalho de Melo

perf report: Implement browsing of individual samples

2019-03-11T19:33:19Z

Now 'perf report' can show whole time periods with 'perf script', but the user still has to find individual samples of interest manually. It would be expensive and complicated to search for the right samples in the whole perf file. Typically users only need to look at a small number of samples for useful analysis. Also the full scripts tend to show samples of all CPUs and all threads mixed up, which can be very confusing on larger systems. Add a new --samples option to save a small random number of samples per hist entry. Use a reservoir sample technique to select a representatve number of samples. Then allow browsing the samples using 'perf script' as part of the hist entry context menu. This automatically adds the right filters, so only the thread or cpu of the sample is displayed. Then we use less' search functionality to directly jump the to the time stamp of the selected sample. It uses different menus for assembler and source display. Assembler needs xed installed and source needs debuginfo. Currently it only supports as many samples as fit on the screen due to some limitations in the slang ui code. Signed-off-by: Andi Kleen Tested-by: Arnaldo Carvalho de Melo Acked-by: Jiri Olsa Link: http://lkml.kernel.org/r/20190311174605.GA29294@tassilo.jf.intel.com Signed-off-by: Arnaldo Carvalho de Melo

perf report: Support time sort key

2019-03-11T19:32:31Z

Add a time sort key to perf report to display samples for different time quantums separately. This allows easier analysis of workloads that change over time, and also will allow looking at the context of samples. % perf record ... % perf report --sort time,overhead,symbol --time-quantum 1ms --stdio ... 0.67% 277061.87300 [.] _dl_start 0.50% 277061.87300 [.] f1 0.50% 277061.87300 [.] f2 0.33% 277061.87300 [.] main 0.29% 277061.87300 [.] _dl_lookup_symbol_x 0.29% 277061.87300 [.] dl_main 0.29% 277061.87300 [.] do_lookup_x 0.17% 277061.87300 [.] _dl_debug_initialize 0.17% 277061.87300 [.] _dl_init_paths 0.08% 277061.87300 [.] check_match 0.04% 277061.87300 [.] _dl_count_modids 1.33% 277061.87400 [.] f1 1.33% 277061.87400 [.] f2 1.33% 277061.87400 [.] main 1.17% 277061.87500 [.] main 1.08% 277061.87500 [.] f1 1.08% 277061.87500 [.] f2 1.00% 277061.87600 [.] main 0.83% 277061.87600 [.] f1 0.83% 277061.87600 [.] f2 1.00% 277061.87700 [.] main Committer notes: Rename 'time' argument to hist_time() to htime to overcome this in older distros: cc1: warnings being treated as errors util/hist.c: In function 'hist_time': util/hist.c:251: error: declaration of 'time' shadows a global declaration /usr/include/time.h:186: error: shadowed declaration is here Signed-off-by: Andi Kleen Acked-by: Jiri Olsa Link: http://lkml.kernel.org/r/20190311144502.15423-4-andi@firstfloor.org Signed-off-by: Arnaldo Carvalho de Melo