linux/tools/perf
Linus Torvalds 7ab89417ed perf tools changes for v6.7
Build
 -----
 * Compile BPF programs by default if clang (>= 12.0.1) is available to
   enable more features like kernel lock contention, off-cpu profiling,
   kwork, sample filtering and so on.  It can be disabled by passing
   BUILD_BPF_SKEL=0 to make.
 
 * Produce better error messages for bison on debug build (make DEBUG=1)
   by defining YYDEBUG symbol internally.
 
 perf record
 -----------
 * Track sideband events (like FORK/MMAP) from all CPUs even if perf record
   targets a subset of CPUs only (using -C option).  Otherwise it may lose
   some information happened on a CPU out of the target list.
 
 * Fix checking raw sched_switch tracepoint argument using system BTF.
   This affects off-cpu profiling which attaches a BPF program to the raw
   tracepoint.
 
 perf lock contention
 --------------------
 * Add --lock-cgroup option to see contention by cgroups.  This should be
   used with BPF only (using -b option).
 
     $ sudo perf lock con -ab --lock-cgroup -- sleep 1
      contended   total wait     max wait     avg wait   cgroup
 
            835     14.06 ms     41.19 us     16.83 us   /system.slice/led.service
             25    122.38 us     13.77 us      4.89 us   /
             44     23.73 us      3.87 us       539 ns   /user.slice/user-657345.slice/session-c4.scope
              1       491 ns       491 ns       491 ns   /system.slice/connectd.service
 
 * Add -G/--cgroup-filter option to see contention only for given cgroups.
   This can be useful when you identified a cgroup in the above command and
   want to investigate more on it.  It also works with other output options
   like -t/--threads and -l/--lock-addr.
 
     $ sudo perf lock con -ab -G /user.slice/user-657345.slice/session-c4.scope -- sleep 1
      contended   total wait     max wait     avg wait         type   caller
 
              8     77.11 us     17.98 us      9.64 us     spinlock   futex_wake+0xc8
              2     24.56 us     14.66 us     12.28 us     spinlock   tick_do_update_jiffies64+0x25
              1      4.97 us      4.97 us      4.97 us     spinlock   futex_q_lock+0x2a
 
 * Use per-cpu array for better spinlock tracking.  This is to improve
   performance of the BPF program and to avoid nested contention on a lock
   in the BPF hash map.
 
 * Update callstack check for PowerPC.  To find a representative caller of a
   lock, it needs to look up the call stacks.  It ends the lookup when it sees
   0 in the call stack buffer.  However, PowerPC call stacks can have 0 values
   in the beginning so skip them when it expects valid call stacks after.
 
 perf kwork
 ----------
 * Support 'sched' class (for -k option) so that it can see task scheduling
   event (using sched_switch tracepoint) as well as irq and workqueue items.
 
 * Add perf kwork top subcommand to show more accurate cpu utilization with
   sched class above.  It works both with a recorded data (using perf kwork
   record command) and BPF (using -b option).  Unlike perf top command, it
   does not support interactive mode (yet).
 
     $ sudo perf kwork top -b -k sched
     Starting trace, Hit <Ctrl+C> to stop and report
     ^C
     Total  : 160702.425 ms, 8 cpus
     %Cpu(s):  36.00% id,   0.00% hi,   0.00% si
     %Cpu0   [||||||||||||||||||              61.66%]
     %Cpu1   [||||||||||||||||||              61.27%]
     %Cpu2   [|||||||||||||||||||             66.40%]
     %Cpu3   [||||||||||||||||||              61.28%]
     %Cpu4   [||||||||||||||||||              61.82%]
     %Cpu5   [|||||||||||||||||||||||         77.41%]
     %Cpu6   [||||||||||||||||||              61.73%]
     %Cpu7   [||||||||||||||||||              63.25%]
 
           PID     SPID    %CPU           RUNTIME  COMMMAND
       -------------------------------------------------------------
             0        0   38.72       8089.463 ms  [swapper/1]
             0        0   38.71       8084.547 ms  [swapper/3]
             0        0   38.33       8007.532 ms  [swapper/0]
             0        0   38.26       7992.985 ms  [swapper/6]
             0        0   38.17       7971.865 ms  [swapper/4]
             0        0   36.74       7447.765 ms  [swapper/7]
             0        0   33.59       6486.942 ms  [swapper/2]
             0        0   22.58       3771.268 ms  [swapper/5]
          9545     9351    2.48        447.136 ms  sched-messaging
          9574     9351    2.09        418.583 ms  sched-messaging
          9724     9351    2.05        372.407 ms  sched-messaging
          9531     9351    2.01        368.804 ms  sched-messaging
          9512     9351    2.00        362.250 ms  sched-messaging
          9514     9351    1.95        357.767 ms  sched-messaging
          9538     9351    1.86        384.476 ms  sched-messaging
          9712     9351    1.84        386.490 ms  sched-messaging
          9723     9351    1.83        380.021 ms  sched-messaging
          9722     9351    1.82        382.738 ms  sched-messaging
          9517     9351    1.81        354.794 ms  sched-messaging
          9559     9351    1.79        344.305 ms  sched-messaging
          9725     9351    1.77        365.315 ms  sched-messaging
     <SNIP>
 
 * Add hard/soft-irq statistics to perf kwork top.  This will show the
   total CPU utilization with IRQ stats like below:
 
     $ sudo perf kwork top -b -k sched,irq,softirq
     Starting trace, Hit <Ctrl+C> to stop and report
     ^C
     Total  :  12554.889 ms, 8 cpus
     %Cpu(s):  96.23% id,   0.10% hi,   0.19% si      <---- here
     %Cpu0   [|                                4.60%]
     %Cpu1   [|                                4.59%]
     %Cpu2   [                                 2.73%]
     %Cpu3   [|                                3.81%]
     <SNIP>
 
 perf bench
 ----------
 * Add -G/--cgroups option to perf bench sched pipe.  The pipe bench is
   good to measure context switch overhead.  With this option, it puts
   the reader and writer tasks in separate cgroups to enforce context
   switch between two different cgroups.
 
   Also it needs to set CPU affinity of the tasks in a CPU to accurately
   measure the impact of cgroup context switches.
 
     $ sudo perf stat -e context-switches,cgroup-switches -- \
     > taskset -c 0 perf bench sched pipe -l 100000
     # Running 'sched/pipe' benchmark:
     # Executed 100000 pipe operations between two processes
 
          Total time: 0.307 [sec]
 
            3.078180 usecs/op
              324867 ops/sec
 
      Performance counter stats for 'taskset -c 0 perf bench sched pipe -l 100000':
 
                200,026      context-switches
                     63      cgroup-switches
 
            0.321637922 seconds time elapsed
 
   You can see small number of cgroup-switches because both write and read
   tasks are in the same cgroup.
 
     $ sudo mkdir /sys/fs/cgroup/{AAA,BBB}
 
     $ sudo perf stat -e context-switches,cgroup-switches -- \
     > taskset -c 0 perf bench sched pipe -l 100000 -G AAA,BBB
     # Running 'sched/pipe' benchmark:
     # Executed 100000 pipe operations between two processes
 
          Total time: 0.351 [sec]
 
            3.512990 usecs/op
              284657 ops/sec
 
      Performance counter stats for 'taskset -c 0 perf bench sched pipe -l 100000 -G AAA,BBB':
 
                200,020      context-switches
                200,019      cgroup-switches
 
            0.365034567 seconds time elapsed
 
   Now context-switches and cgroup-switches are almost same.  And you can
   see the pipe operation took little more.
 
 * Kill child processes when perf bench sched messaging exited abnormally.
   Otherwise it'd leave the child doing unnecessary work.
 
 perf test
 ---------
 * Fix various shellcheck issues on the tests written in shell script.
 
 * Skip tests when condition is not satisfied:
   - object code reading test for non-text section addresses.
   - CoreSight test if cs_etm// event is not available.
   - lock contention test if not enough CPUs.
 
 Event parsing
 -------------
 * Make PMU alias name loading lazy to reduce the startup time in the
   event parsing code for perf record, stat and others in the general
   case.
 
 * Lazily compute PMU default config.  In the same sense, delay PMU
   initialization until it's really needed to reduce the startup cost.
 
 * Fix event term values that are raw events.  The event specification
   can have several terms including event name.  But sometimes it clashes
   with raw event encoding which starts with 'r' and has hex-digits.
 
   For example, an event named 'read' should be processed as a normal
   event but it was mis-treated as a raw encoding and caused a failure.
 
     $ perf stat -e 'uncore_imc_free_running/event=read/' -a sleep 1
     event syntax error: '..nning/event=read/'
                                       \___ parser error
     Run 'perf list' for a list of valid events
 
      Usage: perf stat [<options>] [<command>]
 
         -e, --event <event> event selector. use 'perf list' to list available events
 
 Event metrics
 -------------
 * Add "Compat" regex to match event with multiple identifiers.
 
 * Usual updates for Intel, Power10, Arm telemetry/CMN and AmpereOne.
 
 Misc
 ----
 * Assorted memory leak fixes and footprint reduction.
 
 * Add "bpf_skeletons" to perf version --build-options so that users can
   check whether their perf tools have BPF support easily.
 
 * Fix unaligned access in Intel-PT packet decoder found by undefined-behavior
   sanitizer.
 
 * Avoid frequency mode for the dummy event.  Surprisingly it'd impact
   kernel timer tick handler performance by force iterating all PMU events.
 
 * Update bash shell completion for events and metrics.
 
 Signed-off-by: Namhyung Kim <namhyung@kernel.org>
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Merge tag 'perf-tools-for-v6.7-1-2023-11-01' of git://git.kernel.org/pub/scm/linux/kernel/git/perf/perf-tools

Pull perf tools updates from Namhyung Kim:
 "Build:

   - Compile BPF programs by default if clang (>= 12.0.1) is available
     to enable more features like kernel lock contention, off-cpu
     profiling, kwork, sample filtering and so on.

     This can be disabled by passing BUILD_BPF_SKEL=0 to make.

   - Produce better error messages for bison on debug build (make
     DEBUG=1) by defining YYDEBUG symbol internally.

  perf record:

   - Track sideband events (like FORK/MMAP) from all CPUs even if perf
     record targets a subset of CPUs only (using -C option). Otherwise
     it may lose some information happened on a CPU out of the target
     list.

   - Fix checking raw sched_switch tracepoint argument using system BTF.
     This affects off-cpu profiling which attaches a BPF program to the
     raw tracepoint.

  perf lock contention:

   - Add --lock-cgroup option to see contention by cgroups. This should
     be used with BPF only (using -b option).

       $ sudo perf lock con -ab --lock-cgroup -- sleep 1
        contended   total wait     max wait     avg wait   cgroup

              835     14.06 ms     41.19 us     16.83 us   /system.slice/led.service
               25    122.38 us     13.77 us      4.89 us   /
               44     23.73 us      3.87 us       539 ns   /user.slice/user-657345.slice/session-c4.scope
                1       491 ns       491 ns       491 ns   /system.slice/connectd.service

   - Add -G/--cgroup-filter option to see contention only for given
     cgroups.

     This can be useful when you identified a cgroup in the above
     command and want to investigate more on it. It also works with
     other output options like -t/--threads and -l/--lock-addr.

       $ sudo perf lock con -ab -G /user.slice/user-657345.slice/session-c4.scope -- sleep 1
        contended   total wait     max wait     avg wait         type   caller

                8     77.11 us     17.98 us      9.64 us     spinlock   futex_wake+0xc8
                2     24.56 us     14.66 us     12.28 us     spinlock   tick_do_update_jiffies64+0x25
                1      4.97 us      4.97 us      4.97 us     spinlock   futex_q_lock+0x2a

   - Use per-cpu array for better spinlock tracking. This is to improve
     performance of the BPF program and to avoid nested contention on a
     lock in the BPF hash map.

   - Update callstack check for PowerPC. To find a representative caller
     of a lock, it needs to look up the call stacks. It ends the lookup
     when it sees 0 in the call stack buffer. However, PowerPC call
     stacks can have 0 values in the beginning so skip them when it
     expects valid call stacks after.

  perf kwork:

   - Support 'sched' class (for -k option) so that it can see task
     scheduling event (using sched_switch tracepoint) as well as irq and
     workqueue items.

   - Add perf kwork top subcommand to show more accurate cpu utilization
     with sched class above. It works both with a recorded data (using
     perf kwork record command) and BPF (using -b option). Unlike perf
     top command, it does not support interactive mode (yet).

       $ sudo perf kwork top -b -k sched
       Starting trace, Hit <Ctrl+C> to stop and report
       ^C
       Total  : 160702.425 ms, 8 cpus
       %Cpu(s):  36.00% id,   0.00% hi,   0.00% si
       %Cpu0   [||||||||||||||||||              61.66%]
       %Cpu1   [||||||||||||||||||              61.27%]
       %Cpu2   [|||||||||||||||||||             66.40%]
       %Cpu3   [||||||||||||||||||              61.28%]
       %Cpu4   [||||||||||||||||||              61.82%]
       %Cpu5   [|||||||||||||||||||||||         77.41%]
       %Cpu6   [||||||||||||||||||              61.73%]
       %Cpu7   [||||||||||||||||||              63.25%]

             PID     SPID    %CPU           RUNTIME  COMMMAND
         -------------------------------------------------------------
               0        0   38.72       8089.463 ms  [swapper/1]
               0        0   38.71       8084.547 ms  [swapper/3]
               0        0   38.33       8007.532 ms  [swapper/0]
               0        0   38.26       7992.985 ms  [swapper/6]
               0        0   38.17       7971.865 ms  [swapper/4]
               0        0   36.74       7447.765 ms  [swapper/7]
               0        0   33.59       6486.942 ms  [swapper/2]
               0        0   22.58       3771.268 ms  [swapper/5]
            9545     9351    2.48        447.136 ms  sched-messaging
            9574     9351    2.09        418.583 ms  sched-messaging
            9724     9351    2.05        372.407 ms  sched-messaging
            9531     9351    2.01        368.804 ms  sched-messaging
            9512     9351    2.00        362.250 ms  sched-messaging
            9514     9351    1.95        357.767 ms  sched-messaging
            9538     9351    1.86        384.476 ms  sched-messaging
            9712     9351    1.84        386.490 ms  sched-messaging
            9723     9351    1.83        380.021 ms  sched-messaging
            9722     9351    1.82        382.738 ms  sched-messaging
            9517     9351    1.81        354.794 ms  sched-messaging
            9559     9351    1.79        344.305 ms  sched-messaging
            9725     9351    1.77        365.315 ms  sched-messaging
       <SNIP>

   - Add hard/soft-irq statistics to perf kwork top. This will show the
     total CPU utilization with IRQ stats like below:

       $ sudo perf kwork top -b -k sched,irq,softirq
       Starting trace, Hit <Ctrl+C> to stop and report
       ^C
       Total  :  12554.889 ms, 8 cpus
       %Cpu(s):  96.23% id,   0.10% hi,   0.19% si      <---- here
       %Cpu0   [|                                4.60%]
       %Cpu1   [|                                4.59%]
       %Cpu2   [                                 2.73%]
       %Cpu3   [|                                3.81%]
       <SNIP>

  perf bench:

   - Add -G/--cgroups option to perf bench sched pipe. The pipe bench is
     good to measure context switch overhead. With this option, it puts
     the reader and writer tasks in separate cgroups to enforce context
     switch between two different cgroups.

     Also it needs to set CPU affinity of the tasks in a CPU to
     accurately measure the impact of cgroup context switches.

       $ sudo perf stat -e context-switches,cgroup-switches -- \
       > taskset -c 0 perf bench sched pipe -l 100000
       # Running 'sched/pipe' benchmark:
       # Executed 100000 pipe operations between two processes

            Total time: 0.307 [sec]

              3.078180 usecs/op
                324867 ops/sec

        Performance counter stats for 'taskset -c 0 perf bench sched pipe -l 100000':

                  200,026      context-switches
                       63      cgroup-switches

              0.321637922 seconds time elapsed

     You can see small number of cgroup-switches because both write and
     read tasks are in the same cgroup.

       $ sudo mkdir /sys/fs/cgroup/{AAA,BBB}

       $ sudo perf stat -e context-switches,cgroup-switches -- \
       > taskset -c 0 perf bench sched pipe -l 100000 -G AAA,BBB
       # Running 'sched/pipe' benchmark:
       # Executed 100000 pipe operations between two processes

            Total time: 0.351 [sec]

              3.512990 usecs/op
                284657 ops/sec

        Performance counter stats for 'taskset -c 0 perf bench sched pipe -l 100000 -G AAA,BBB':

                  200,020      context-switches
                  200,019      cgroup-switches

              0.365034567 seconds time elapsed

     Now context-switches and cgroup-switches are almost same. And you
     can see the pipe operation took little more.

   - Kill child processes when perf bench sched messaging exited
     abnormally. Otherwise it'd leave the child doing unnecessary work.

  perf test:

   - Fix various shellcheck issues on the tests written in shell script.

   - Skip tests when condition is not satisfied:
      - object code reading test for non-text section addresses.
      - CoreSight test if cs_etm// event is not available.
      - lock contention test if not enough CPUs.

  Event parsing:

   - Make PMU alias name loading lazy to reduce the startup time in the
     event parsing code for perf record, stat and others in the general
     case.

   - Lazily compute PMU default config. In the same sense, delay PMU
     initialization until it's really needed to reduce the startup cost.

   - Fix event term values that are raw events. The event specification
     can have several terms including event name. But sometimes it
     clashes with raw event encoding which starts with 'r' and has
     hex-digits.

     For example, an event named 'read' should be processed as a normal
     event but it was mis-treated as a raw encoding and caused a
     failure.

       $ perf stat -e 'uncore_imc_free_running/event=read/' -a sleep 1
       event syntax error: '..nning/event=read/'
                                         \___ parser error
       Run 'perf list' for a list of valid events

        Usage: perf stat [<options>] [<command>]

           -e, --event <event> event selector. use 'perf list' to list available events

  Event metrics:

   - Add "Compat" regex to match event with multiple identifiers.

   - Usual updates for Intel, Power10, Arm telemetry/CMN and AmpereOne.

  Misc:

   - Assorted memory leak fixes and footprint reduction.

   - Add "bpf_skeletons" to perf version --build-options so that users
     can check whether their perf tools have BPF support easily.

   - Fix unaligned access in Intel-PT packet decoder found by
     undefined-behavior sanitizer.

   - Avoid frequency mode for the dummy event. Surprisingly it'd impact
     kernel timer tick handler performance by force iterating all PMU
     events.

   - Update bash shell completion for events and metrics"

* tag 'perf-tools-for-v6.7-1-2023-11-01' of git://git.kernel.org/pub/scm/linux/kernel/git/perf/perf-tools: (187 commits)
  perf vendor events intel: Update tsx_cycles_per_elision metrics
  perf vendor events intel: Update bonnell version number to v5
  perf vendor events intel: Update westmereex events to v4
  perf vendor events intel: Update meteorlake events to v1.06
  perf vendor events intel: Update knightslanding events to v16
  perf vendor events intel: Add typo fix for ivybridge FP
  perf vendor events intel: Update a spelling in haswell/haswellx
  perf vendor events intel: Update emeraldrapids to v1.01
  perf vendor events intel: Update alderlake/alderlake events to v1.23
  perf build: Disable BPF skeletons if clang version is < 12.0.1
  perf callchain: Fix spelling mistake "statisitcs" -> "statistics"
  perf report: Fix spelling mistake "heirachy" -> "hierarchy"
  perf python: Fix binding linkage due to rename and move of evsel__increase_rlimit()
  perf tests: test_arm_coresight: Simplify source iteration
  perf vendor events intel: Add tigerlake two metrics
  perf vendor events intel: Add broadwellde two metrics
  perf vendor events intel: Fix broadwellde tma_info_system_dram_bw_use metric
  perf mem_info: Add and use map_symbol__exit and addr_map_symbol__exit
  perf callchain: Minor layout changes to callchain_list
  perf callchain: Make brtype_stat in callchain_list optional
  ...
2023-11-03 08:17:38 -10:00
..
arch perf tools changes for v6.7 2023-11-03 08:17:38 -10:00
bench perf bench sched pipe: Add -G/--cgroups option 2023-10-25 10:02:10 -07:00
dlfilters perf dlfilter: Add a test for object_code() 2023-09-30 00:09:06 -07:00
Documentation perf bench sched pipe: Add -G/--cgroups option 2023-10-25 10:02:10 -07:00
include/perf
jvmti
pmu-events perf vendor events intel: Update tsx_cycles_per_elision metrics 2023-10-28 00:45:27 -07:00
python
scripts
tests perf tests: test_arm_coresight: Simplify source iteration 2023-10-26 10:58:10 -07:00
trace perf tools changes for v6.6: 2023-09-09 20:06:17 -07:00
ui perf hists browser: Avoid potential NULL dereference 2023-10-12 10:01:56 -07:00
util perf tools changes for v6.7 2023-11-03 08:17:38 -10:00
.gitignore
Build
builtin-annotate.c
builtin-bench.c perf tools changes for v6.6: 2023-09-09 20:06:17 -07:00
builtin-buildid-cache.c perf buildid-cache: Fix use of uninitialized value 2023-10-12 10:01:56 -07:00
builtin-buildid-list.c
builtin-c2c.c
builtin-config.c
builtin-daemon.c
builtin-data.c
builtin-diff.c
builtin-evlist.c
builtin-ftrace.c
builtin-help.c
builtin-inject.c
builtin-kallsyms.c
builtin-kmem.c
builtin-kvm.c
builtin-kwork.c perf kwork: Fix spelling mistake "Captuer" -> "Capture" 2023-09-26 21:47:11 -07:00
builtin-list.c perf list: Don't print Unit for "default_core" 2023-08-31 16:24:47 -03:00
builtin-lock.c perf lock: Fix a memory leak on an error path 2023-10-12 10:01:57 -07:00
builtin-mem.c
builtin-probe.c
builtin-record.c perf record: Track sideband events for all CPUs when tracing selected CPUs 2023-09-12 17:31:43 -03:00
builtin-report.c perf report: Fix spelling mistake "heirachy" -> "hierarchy" 2023-10-27 19:25:13 -07:00
builtin-sched.c libperf rc_check: Add RC_CHK_EQUAL 2023-10-25 13:37:22 -07:00
builtin-script.c perf: script: fix missing ',' for fields option 2023-10-17 12:40:51 -07:00
builtin-stat.c perf stat: Fix aggr mode initialization 2023-09-11 10:26:35 -03:00
builtin-timechart.c
builtin-top.c
builtin-trace.c
builtin-version.c perf version: Add status of bpf skeletons 2023-09-18 16:46:15 -07:00
builtin.h
check-headers.sh perf tools: Add get_unaligned_leNN() 2023-10-17 12:40:02 -07:00
command-list.txt
CREDITS
design.txt
Makefile
Makefile.config perf build: Disable BPF skeletons if clang version is < 12.0.1 2023-10-27 19:27:33 -07:00
Makefile.perf perf tools changes for v6.7 2023-11-03 08:17:38 -10:00
MANIFEST
perf-archive.sh
perf-completion.sh perf shell completion: Support completion of metrics/metricgroups 2023-09-11 10:26:36 -03:00
perf-iostat.sh
perf-read-vdso.c
perf-sys.h
perf.c
perf.h