kernel/linux.git/tools/perf/Documentation, branch v6.12.80

perf tools: Fix up some comments and code to properly use the event_source bus

2025-04-07T08:08:36+00:00

commit 0cced76a0276610e86e8b187c09f0e9ef85b9299 upstream. In sysfs, the perf events are all located in /sys/bus/event_source/devices/ but some places ended up hard-coding the location to be at the root of /sys/devices/ which could be very risky as you do not exactly know what type of device you are accessing in sysfs at that location. So fix this all up by properly pointing everything at the bus device list instead of the root of the sysfs devices/ tree. Cc: stable Signed-off-by: Greg Kroah-Hartman Reviewed-by: Kan Liang Link: https://lore.kernel.org/r/2025021955-implant-excavator-179d@gregkh Signed-off-by: Namhyung Kim Signed-off-by: Greg Kroah-Hartman

perf check: Fix inconsistencies in feature names

2024-09-04T19:19:53+00:00

Fix two inconsistencies in feature names as discussed in [1]: 1. Rename "dwarf-unwind-support" to "dwarf-unwind" 2. 'get_cpuid' feature and 'HAVE_AUXTRACE_SUPPORT' names don't look related, change the feature name to 'auxtrace' to match the macro name, as 'get_cpuid' string is not used anywhere to check the feature presence [1]: https://lore.kernel.org/linux-perf-users/ZoRw5we4HLSTZND6@x1/ Suggested-by: Arnaldo Carvalho de Melo Signed-off-by: Aditya Gupta Cc: Athira Rajeev Cc: Disha Goel Cc: Ian Rogers Cc: Jiri Olsa Cc: Kajol Jain Cc: Madhavan Srinivasan Cc: Namhyung Kim Link: https://lore.kernel.org/r/20240904190132.415212-7-adityag@linux.ibm.com Signed-off-by: Arnaldo Carvalho de Melo

perf check: Introduce 'check' subcommand

2024-09-04T12:56:05+00:00

Currently the presence of a feature is checked with a combination of perf version --build-options and greps, such as: perf version --build-options | grep " on .* HAVE_FEATURE" Instead of this, introduce a subcommand "perf check feature", with which scripts can test for presence of a feature, such as: perf check feature HAVE_FEATURE 'perf check feature' command is expected to have exit status of 0 if feature is built-in, and 1 if it's not built-in or if feature is not known. Multiple features can also be passed as a comma-separated list, in which case the exit status will be 1 only if all of the passed features are built-in. For example, with below command, it will have exit status of 0 only if both libtraceevent and bpf are enabled, else 1 in all other cases perf check feature libtraceevent,bpf The arguments are case-insensitive. An array 'supported_features' has also been introduced that can be used by other commands like 'perf version --build-options', so that new features can be added in one place, with the array Committer testing: $ perf check feature libtraceevent,bpf libtraceevent: [ on ] # HAVE_LIBTRACEEVENT bpf: [ on ] # HAVE_LIBBPF_SUPPORT $ perf check feature libtraceevent libtraceevent: [ on ] # HAVE_LIBTRACEEVENT $ perf check feature bpf bpf: [ on ] # HAVE_LIBBPF_SUPPORT $ perf check -q feature bpf && echo "BPF support is present" BPF support is present $ perf check -q feature Bogus && echo "Bogus support is present" $ Reviewed-by: Athira Rajeev Signed-off-by: Aditya Gupta Tested-by: Arnaldo Carvalho de Melo Cc: Athira Rajeev Cc: Disha Goel Cc: Ian Rogers Cc: Jiri Olsa Cc: Kajol Jain Cc: Madhavan Srinivasan Cc: Namhyung Kim Link: https://lore.kernel.org/r/20240904061836.55873-3-adityag@linux.ibm.com Signed-off-by: Arnaldo Carvalho de Melo

perf sched timehist: Add --prio option

2024-09-03T18:45:59+00:00

The --prio option is used to only show events for the given task priority(ies). The default is to show events for all priority tasks, which is consistent with the previous behavior. Testcase: # perf sched record nice -n 9 perf bench sched messaging -l 10000 # Running 'sched/messaging' benchmark: # 20 sender and receiver processes per group # 10 groups == 400 processes run Total time: 3.435 [sec] [ perf record: Woken up 270 times to write data ] [ perf record: Captured and wrote 618.688 MB perf.data (5729036 samples) ] # perf sched timehist -h Usage: perf sched timehist [] -C, --cpu list of cpus to profile -D, --dump-raw-trace dump raw trace in ASCII -f, --force don't complain, do it -g, --call-graph Display call chains if present (default on) -I, --idle-hist Show idle events only -i, --input input file name -k, --vmlinux vmlinux pathname -M, --migrations Show migration events -n, --next Show next task -p, --pid analyze events only for given process id(s) -s, --summary Show only syscall summary with statistics -S, --with-summary Show all syscalls and summary with statistics -t, --tid analyze events only for given thread id(s) -V, --cpu-visual Add CPU visual -v, --verbose be more verbose (show symbol address, etc) -w, --wakeups Show wakeup events --kallsyms kallsyms pathname --max-stack Maximum number of functions to display backtrace. --prio analyze events only for given task priority(ies) --show-prio Show task priority --state Show task state when sched-out --symfs Look for files with symbols relative to this directory --time Time span for analysis (start,stop) # perf sched timehist --prio 140 Samples of sched_switch event do not have callchains. Invalid prio string # perf sched timehist --show-prio --prio 129 Samples of sched_switch event do not have callchains. time cpu task name prio wait time sch delay run time [tid/pid] (msec) (msec) (msec) --------------- ------ ------------------------------ -------- --------- --------- --------- 2090450.765421 [0002] sched-messaging[1229618] 129 0.000 0.000 0.029 2090450.765445 [0007] sched-messaging[1229616] 129 0.000 0.062 0.043 2090450.765448 [0014] sched-messaging[1229619] 129 0.000 0.000 0.032 2090450.765478 [0013] sched-messaging[1229617] 129 0.000 0.065 0.048 2090450.765503 [0014] sched-messaging[1229622] 129 0.000 0.000 0.017 2090450.765550 [0002] sched-messaging[1229624] 129 0.000 0.000 0.021 2090450.765562 [0007] sched-messaging[1229621] 129 0.000 0.071 0.028 2090450.765570 [0005] sched-messaging[1229620] 129 0.000 0.064 0.066 2090450.765583 [0001] sched-messaging[1229625] 129 0.000 0.001 0.031 2090450.765595 [0013] sched-messaging[1229623] 129 0.000 0.060 0.028 2090450.765637 [0014] sched-messaging[1229628] 129 0.000 0.000 0.019 2090450.765665 [0007] sched-messaging[1229627] 129 0.000 0.038 0.030 # perf sched timehist --show-prio --prio 0,120-129 Samples of sched_switch event do not have callchains. time cpu task name prio wait time sch delay run time [tid/pid] (msec) (msec) (msec) --------------- ------ ------------------------------ -------- --------- --------- --------- 2090450.763231 [0000] perf[1229608] 120 0.000 0.000 0.000 2090450.763235 [0000] migration/0[15] 0 0.000 0.001 0.003 2090450.763263 [0001] perf[1229608] 120 0.000 0.000 0.000 2090450.763268 [0001] migration/1[21] 0 0.000 0.001 0.004 2090450.763302 [0002] perf[1229608] 120 0.000 0.000 0.000 2090450.763309 [0002] migration/2[27] 0 0.000 0.001 0.007 2090450.763338 [0003] perf[1229608] 120 0.000 0.000 0.000 2090450.763343 [0003] migration/3[33] 0 0.000 0.001 0.004 2090450.763459 [0004] perf[1229608] 120 0.000 0.000 0.000 2090450.763469 [0004] migration/4[39] 0 0.000 0.002 0.010 2090450.763496 [0005] perf[1229608] 120 0.000 0.000 0.000 2090450.763501 [0005] migration/5[45] 0 0.000 0.001 0.004 2090450.763613 [0006] perf[1229608] 120 0.000 0.000 0.000 2090450.763622 [0006] migration/6[51] 0 0.000 0.001 0.008 2090450.763652 [0007] perf[1229608] 120 0.000 0.000 0.000 2090450.763660 [0007] migration/7[57] 0 0.000 0.001 0.008 2090450.765665 [0001] 120 0.031 0.031 0.081 2090450.765665 [0007] sched-messaging[1229627] 129 0.000 0.038 0.030 2090450.765667 [0000] s1-perf[8235/7168] 120 0.008 0.000 0.004 2090450.765684 [0013] 120 0.028 0.028 0.088 2090450.765685 [0001] sched-messaging[1229630] 129 0.000 0.001 0.020 2090450.765688 [0000] 120 0.004 0.004 0.020 2090450.765689 [0002] 120 0.021 0.021 0.138 2090450.765691 [0005] sched-messaging[1229626] 129 0.000 0.085 0.029 Signed-off-by: Yang Jihong Acked-by: Namhyung Kim Cc: Adrian Hunter Cc: Alexander Shishkin Cc: Ian Rogers Cc: Ingo Molnar Cc: James Clark Cc: Jiri Olsa Cc: Kan Liang Cc: Mark Rutland Cc: Peter Zijlstra Link: https://lore.kernel.org/r/20240819033016.2427235-3-yangjihong@bytedance.com Signed-off-by: Arnaldo Carvalho de Melo

perf sched timehist: Add --show-prio option

2024-09-03T18:45:34+00:00

The --show-prio option is used to display the priority of task. It is disabled by default, which is consistent with original behavior. The display format is xxx (priority does not change during task running) or xxx->yyy (priority changes during task running) Testcase: # perf sched record nice -n 9 true [ perf record: Woken up 0 times to write data ] [ perf record: Captured and wrote 0.497 MB perf.data ] # perf sched timehist -h Usage: perf sched timehist [] -C, --cpu list of cpus to profile -D, --dump-raw-trace dump raw trace in ASCII -f, --force don't complain, do it -g, --call-graph Display call chains if present (default on) -I, --idle-hist Show idle events only -i, --input input file name -k, --vmlinux vmlinux pathname -M, --migrations Show migration events -n, --next Show next task -p, --pid analyze events only for given process id(s) -s, --summary Show only syscall summary with statistics -S, --with-summary Show all syscalls and summary with statistics -t, --tid analyze events only for given thread id(s) -V, --cpu-visual Add CPU visual -v, --verbose be more verbose (show symbol address, etc) -w, --wakeups Show wakeup events --kallsyms kallsyms pathname --max-stack Maximum number of functions to display backtrace. --show-prio Show task priority --state Show task state when sched-out --symfs Look for files with symbols relative to this directory --time Time span for analysis (start,stop) # perf sched timehist Samples of sched_switch event do not have callchains. time cpu task name wait time sch delay run time [tid/pid] (msec) (msec) (msec) --------------- ------ ------------------------------ --------- --------- --------- 23952.006537 [0000] perf[534] 0.000 0.000 0.000 23952.006593 [0000] migration/0[19] 0.000 0.014 0.056 23952.006899 [0001] perf[534] 0.000 0.000 0.000 23952.006947 [0001] migration/1[22] 0.000 0.015 0.047 23952.007138 [0002] perf[534] 0.000 0.000 0.000 # perf sched timehist --show-prio Samples of sched_switch event do not have callchains. time cpu task name prio wait time sch delay run time [tid/pid] (msec) (msec) (msec) --------------- ------ ------------------------------ -------- --------- --------- --------- 23952.006537 [0000] perf[534] 120 0.000 0.000 0.000 23952.006593 [0000] migration/0[19] 0 0.000 0.014 0.056 23952.006899 [0001] perf[534] 120 0.000 0.000 0.000 23952.034843 [0003] nice[535] 120->129 0.189 0.024 23.314 23952.053838 [0005] rcu_preempt[16] 120 3.993 0.000 0.023 23952.053990 [0005] 120 0.023 0.023 0.152 23952.054137 [0006] 120 1.427 1.427 17.855 23952.054278 [0007] 120 0.506 0.506 1.650 Signed-off-by: Yang Jihong Acked-by: Namhyung Kim Cc: Adrian Hunter Cc: Alexander Shishkin Cc: Ian Rogers Cc: Ingo Molnar Cc: James Clark Cc: Jiri Olsa Cc: Kan Liang Cc: Mark Rutland Cc: Peter Zijlstra Link: https://lore.kernel.org/r/20240819033016.2427235-2-yangjihong@bytedance.com Signed-off-by: Arnaldo Carvalho de Melo

perf script: Add branch counters

2024-08-14T13:20:40+00:00

It's useful to print the branch counter information for each jump in the brstackinsn when it's available. Add a new field 'brcntr' to display the branch counter information. By default, the abbreviation will be used to indicate the branch counter. In the verbose mode, the real event name is shown. $ perf script -F +brstackinsn,+brcntr # Branch counter abbr list: # branch-instructions:ppp = A # branch-misses = B # '-' No event occurs # '+' Event occurrences may be lost due to branch counter saturated tchain_edit 332203 3366329.405674: 53030 branch-instructions:ppp: 401781 f3+0x2c (home/sdp/test/tchain_edit) f3+31: 0000000000401774 insn: eb 04 br_cntr: AA # PRED 5 cycles [5] 000000000040177a insn: 81 7d fc 0f 27 00 00 0000000000401781 insn: 7e e3 br_cntr: A # PRED 1 cycles [6] 2.00 IPC 0000000000401766 insn: 8b 45 fc 0000000000401769 insn: 83 e0 01 000000000040176c insn: 85 c0 000000000040176e insn: 74 06 br_cntr: A # PRED 1 cycles [7] 4.00 IPC 0000000000401776 insn: 83 45 fc 01 000000000040177a insn: 81 7d fc 0f 27 00 00 0000000000401781 insn: 7e e3 br_cntr: A # PRED 7 cycles [14] 0.43 IPC $ perf script -F +brstackinsn,+brcntr -v tchain_edit 332203 3366329.405674: 53030 branch-instructions:ppp: 401781 f3+0x2c (/home/sdp/os.linux.perf.test-suite/kernels/lbr_kernel/tchain_edit) f3+31: 0000000000401774 insn: eb 04 br_cntr: branch-instructions:ppp 2 branch-misses 0 # PRED 5 cycles [5] 000000000040177a insn: 81 7d fc 0f 27 00 00 0000000000401781 insn: 7e e3 br_cntr: branch-instructions:ppp 1 branch-misses 0 # PRED 1 cycles [6] 2.00 IPC 0000000000401766 insn: 8b 45 fc 0000000000401769 insn: 83 e0 01 000000000040176c insn: 85 c0 000000000040176e insn: 74 06 br_cntr: branch-instructions:ppp 1 branch-misses 0 # PRED 1 cycles [7] 4.00 IPC 0000000000401776 insn: 83 45 fc 01 000000000040177a insn: 81 7d fc 0f 27 00 00 0000000000401781 insn: 7e e3 br_cntr: branch-instructions:ppp 1 branch-misses 0 # PRED 7 cycles [14] 0.43 IPC Originally-by: Tinghao Zhang Reviewed-by: Andi Kleen Signed-off-by: Kan Liang Acked-by: Namhyung Kim Cc: Adrian Hunter Cc: Ian Rogers Cc: Ingo Molnar Cc: Peter Zijlstra Cc: Stephane Eranian Link: https://lore.kernel.org/r/20240813160208.2493643-9-kan.liang@linux.intel.com Signed-off-by: Arnaldo Carvalho de Melo

perf report: Display the branch counter histogram

2024-08-14T13:20:40+00:00

Reusing the existing --total-cycles option to display the branch counters. Add a new PERF_HPP_REPORT__BLOCK_BRANCH_COUNTER to display the logged branch counter events. They are shown right after all the cycle-related annotations. Extend the 'struct block_info' to store and pass the branch counter related information. The annotation_br_cntr_entry() is to print the histogram of each branch counter event. If the number of logged events is less than 4, the exact number of the abbr name is printed. Otherwise, using '+' to stands for more than 3 events. Assume the number of logged events is less than 4. The annotation_br_cntr_abbr_list() prints the branch counter's abbreviation list. Press 'B' to display the list in the TUI mode. $ perf record -e "{branch-instructions:ppp,branch-misses}:S" -j any,counter $ perf report --total-cycles --stdio # To display the perf.data header info, please use --header/--header-only options. # # # Total Lost Samples: 0 # # Samples: 1M of events 'anon group { branch-instructions:ppp, branch-misses }' # Event count (approx.): 1610046 # # Branch counter abbr list: # branch-instructions:ppp = A # branch-misses = B # '-' No event occurs # '+' Event occurrences may be lost due to branch counter saturated # # Sampled Cycles% Sampled Cycles Avg Cycles% Avg Cycles Branch Counter [Program Block Range] # ............... .............. ........... .......... .............. .................. # 57.55% 2.5M 0.00% 3 |A |- | ... 25.27% 1.1M 0.00% 2 |AA |- | ... 15.61% 667.2K 0.00% 1 |A |- | ... 0.16% 6.9K 0.81% 575 |A |- | ... 0.16% 6.8K 1.38% 977 |AA |- | ... 0.16% 6.8K 0.04% 28 |AA |B | ... 0.15% 6.6K 1.33% 946 |A |- | ... 0.11% 4.5K 0.06% 46 |AAA+|- | ... 0.10% 4.4K 0.88% 624 |A |- | ... 0.09% 3.7K 0.74% 524 |AAA+|B | ... With -v applied, # Sampled Cycles% Sampled Cycles Avg Cycles% Avg Cycles Branch Counter [Program Block Range] # ............... .............. ........... .......... .............. .................. # 57.55% 2.5M 0.00% 3 A=1 ,B=- ... 25.27% 1.1M 0.00% 2 A=2 ,B=- ... 15.61% 667.2K 0.00% 1 A=1 ,B=- ... 0.16% 6.9K 0.81% 575 A=1 ,B=- ... 0.16% 6.8K 1.38% 977 A=2 ,B=- ... 0.16% 6.8K 0.04% 28 A=2 ,B=1 ... 0.15% 6.6K 1.33% 946 A=1 ,B=- ... 0.11% 4.5K 0.06% 46 A=3+,B=- ... 0.10% 4.4K 0.88% 624 A=1 ,B=- ... 0.09% 3.7K 0.74% 524 A=3+,B=1 ... Reviewed-by: Andi Kleen Signed-off-by: Kan Liang Acked-by: Namhyung Kim Cc: Adrian Hunter Cc: Ian Rogers Cc: Ingo Molnar Cc: Peter Zijlstra Cc: Stephane Eranian Link: https://lore.kernel.org/r/20240813160208.2493643-7-kan.liang@linux.intel.com Signed-off-by: Arnaldo Carvalho de Melo

perf Document: Add TPEBS (Timed PEBS(Precise Event-Based Sampling)) to Documents

2024-08-13T18:25:33+00:00

TPEBS (Timed PEBS(Precise Event-Based Sampling)) is a new feature Intel PMU from Granite Rapids microarchitecture. It will be used in new TMA (Top-Down Microarchitecture Analysis) releases. Add related introduction to documents while adding new code to support it in 'perf stat'. Reviewed-by: Namhyung Kim Signed-off-by: Weilin Wang Acked-by: Ian Rogers Cc: Adrian Hunter Cc: Alexander Shishkin Cc: Caleb Biggers Cc: Ingo Molnar Cc: Jiri Olsa Cc: Kan Liang Cc: Perry Taylor Cc: Peter Zijlstra Cc: Samantha Alt Link: https://lore.kernel.org/r/20240720062102.444578-8-weilin.wang@intel.com Signed-off-by: Arnaldo Carvalho de Melo

perf stat: Add command line option for enabling TPEBS recording

2024-08-13T18:25:32+00:00

With this command line option, TPEBS recording is turned off in 'perf stat' on default. It will only be turned on when this option is given in 'perf stat' command. Example with --record-tpebs: perf stat -M tma_split_loads -C1-4 --record-tpebs sleep 1 [ perf record: Woken up 2 times to write data ] [ perf record: Captured and wrote 0.044 MB - ] Performance counter stats for 'CPU(s) 1-4': 53,259,156,071 cpu_core/TOPDOWN.SLOTS/ # 1.6 % tma_split_loads (50.00%) 15,867,565,250 cpu_core/topdown-retiring/ (50.00%) 15,655,580,731 cpu_core/topdown-mem-bound/ (50.00%) 11,738,022,218 cpu_core/topdown-bad-spec/ (50.00%) 6,151,265,424 cpu_core/topdown-fe-bound/ (50.00%) 20,445,917,581 cpu_core/topdown-be-bound/ (50.00%) 6,925,098,013 cpu_core/L1D_PEND_MISS.PENDING/ (50.00%) 3,838,653,421 cpu_core/MEMORY_ACTIVITY.STALLS_L1D_MISS/ (50.00%) 4,797,059,783 cpu_core/EXE_ACTIVITY.BOUND_ON_LOADS/ (50.00%) 11,931,916,714 cpu_core/CPU_CLK_UNHALTED.THREAD/ (50.00%) 102,576,164 cpu_core/MEM_LOAD_COMPLETED.L1_MISS_ANY/ (50.00%) 64,071,854 cpu_core/MEM_INST_RETIRED.SPLIT_LOADS/ (50.00%) 3 cpu_core/MEM_INST_RETIRED.SPLIT_LOADS/R 1.003049679 seconds time elapsed Example without --record-tpebs: perf stat -M tma_contested_accesses -C1 sleep 1 Performance counter stats for 'CPU(s) 1': 50,203,891 cpu_core/TOPDOWN.SLOTS/ # 0.0 % tma_contested_accesses (63.60%) 10,040,777 cpu_core/topdown-retiring/ (63.60%) 6,890,729 cpu_core/topdown-mem-bound/ (63.60%) 2,756,463 cpu_core/topdown-bad-spec/ (63.60%) 10,828,288 cpu_core/topdown-fe-bound/ (63.60%) 28,350,432 cpu_core/topdown-be-bound/ (63.60%) 98 cpu_core/OCR.DEMAND_DATA_RD.L3_HIT.SNOOP_HITM/ (63.70%) 577,520 cpu_core/MEMORY_ACTIVITY.STALLS_L2_MISS/ (54.62%) 313,339 cpu_core/MEMORY_ACTIVITY.STALLS_L3_MISS/ (54.62%) 14,155 cpu_core/MEM_LOAD_RETIRED.L1_MISS/ (45.54%) 0 cpu_core/OCR.DEMAND_DATA_RD.L3_HIT.SNOOP_HIT_WITH_FWD/ (36.30%) 8,468,077 cpu_core/CPU_CLK_UNHALTED.THREAD/ (45.38%) 198 cpu_core/MEM_LOAD_L3_HIT_RETIRED.XSNP_MISS/ (45.38%) 8,324 cpu_core/MEM_LOAD_RETIRED.FB_HIT/ (45.38%) 3,388,031,520 TSC 23,226,785 cpu_core/CPU_CLK_UNHALTED.REF_TSC/ (54.46%) 80 cpu_core/MEM_LOAD_L3_HIT_RETIRED.XSNP_FWD/ (54.46%) 0 cpu_core/MEM_LOAD_L3_HIT_RETIRED.XSNP_FWD/R 0 cpu_core/MEM_LOAD_L3_HIT_RETIRED.XSNP_MISS/R 1,006,816,667 ns duration_time 1.002537737 seconds time elapsed Reviewed-by: Namhyung Kim Signed-off-by: Weilin Wang Acked-by: Ian Rogers Cc: Adrian Hunter Cc: Alexander Shishkin Cc: Caleb Biggers Cc: Ingo Molnar Cc: Jiri Olsa Cc: Kan Liang Cc: Perry Taylor Cc: Peter Zijlstra Cc: Samantha Alt Link: https://lore.kernel.org/r/20240720062102.444578-7-weilin.wang@intel.com Signed-off-by: Arnaldo Carvalho de Melo

perf docs: Refine the description for the buffer size

2024-08-12T16:59:22+00:00

Current description for the AUX trace buffer size is misleading. When a user specifies the option '-m,512M', it represents a size value in bytes (512MiB) but not 512M pages (512M x 4KiB regard to a page of 4KiB). Make the document clear that the normal buffer and the AUX tracing buffer share the same semantics. Syncs the documents for consistent text. Reviewed-by: James Clark Signed-off-by: Leo Yan Cc: Adrian Hunter Cc: Ingo Molnar Cc: Jiri Olsa Cc: Kan Liang Cc: Namhyung Kim Cc: Peter Zijlstra Link: https://lore.kernel.org/r/20240812093459.2575278-1-leo.yan@arm.com Signed-off-by: Arnaldo Carvalho de Melo