perf-lock(1) — Linux manual page

NAME | SYNOPSIS | DESCRIPTION | COMMON OPTIONS | REPORT OPTIONS | INFO OPTIONS | CONTENTION OPTIONS | SEE ALSO | COLOPHON

PERF-LOCK(1)                   perf Manual                  PERF-LOCK(1)

NAME         top

       perf-lock - Analyze lock events

SYNOPSIS         top

       perf lock {record|report|script|info|contention}

DESCRIPTION         top

       You can analyze various lock behaviours and statistics with this
       perf lock command.

           'perf lock record <command>' records lock events
           between start and end <command>. And this command
           produces the file "perf.data" which contains tracing
           results of lock events.

           'perf lock report' reports statistical data.

           'perf lock script' shows raw lock events.

           'perf lock info' shows metadata like threads or addresses
           of lock instances.

           'perf lock contention' shows contention statistics.

COMMON OPTIONS         top

       -i, --input=<file>
           Input file name. (default: perf.data unless stdin is a fifo)

       --output=<file>
           Output file name for perf lock contention and report.

       -v, --verbose
           Be more verbose (show symbol address, etc).

       -q, --quiet
           Do not show any warnings or messages. (Suppress -v)

       -D, --dump-raw-trace
           Dump raw trace in ASCII.

       -f, --force
           Don’t complain, do it.

       --vmlinux=<file>
           vmlinux pathname

       --kallsyms=<file>
           kallsyms pathname

REPORT OPTIONS         top

       -k, --key=<value>
           Sorting key. Possible values: acquired (default), contended,
           avg_wait, wait_total, wait_max, wait_min.

       -F, --field=<value>
           Output fields. By default it shows all the fields but users
           can customize that using this. Possible values: acquired,
           contended, avg_wait, wait_total, wait_max, wait_min.

       -c, --combine-locks
           Merge lock instances in the same class (based on name).

       -t, --threads
           The -t option is to show per-thread lock stat like below:

               $ perf lock report -t -F acquired,contended,avg_wait

               Name   acquired  contended   avg wait (ns)

                          perf     240569          9            5784
                       swapper     106610         19             543
                        :15789      17370          2           14538
                  ContainerMgr       8981          6             874
                         sleep       5275          1           11281
               ContainerThread       4416          4             944
               RootPressureThr       3215          5            1215
                   rcu_preempt       2954          0               0
                  ContainerMgr       2560          0               0
                       unnamed       1873          0               0
               EventManager_De       1845          1             636
               futex-default-S       1609          0               0

       -E, --entries=<value>
           Display this many entries.

INFO OPTIONS         top

       -t, --threads
           dump thread list in perf.data

       -m, --map
           dump map of lock instances (address:name table)

CONTENTION OPTIONS         top

       -k, --key=<value>
           Sorting key. Possible values: contended, wait_total
           (default), wait_max, wait_min, avg_wait.

       -F, --field=<value>
           Output fields. By default it shows all but the wait_min
           fields and users can customize that using this. Possible
           values: contended, wait_total, wait_max, wait_min, avg_wait.

       -t, --threads
           Show per-thread lock contention stat

       -b, --use-bpf
           Use BPF program to collect lock contention stats instead of
           using the input data.

       -a, --all-cpus
           System-wide collection from all CPUs.

       -C, --cpu=<value>
           Collect samples only on the list of CPUs provided. Multiple
           CPUs can be provided as a comma-separated list with no space:
           0,1. Ranges of CPUs are specified with -: 0-2. Default is to
           monitor all CPUs.

       -p, --pid=<value>
           Record events on existing process ID (comma separated list).

       --tid=<value>
           Record events on existing thread ID (comma separated list).

       -M, --map-nr-entries=<value>
           Maximum number of BPF map entries (default: 16384). This will
           be aligned to a power of 2.

       --max-stack=<value>
           Maximum stack depth when collecting lock contention (default:
           8).

       --stack-skip=<value>
           Number of stack depth to skip when finding a lock caller
           (default: 3).

       -E, --entries=<value>
           Display this many entries.

       -l, --lock-addr
           Show lock contention stat by address

       -o, --lock-owner
           Show lock contention stat by owners. Implies --threads and
           requires --use-bpf.

       -Y, --type-filter=<value>
           Show lock contention only for given lock types (comma
           separated list). Available values are: semaphore, spinlock,
           rwlock, rwlock:R, rwlock:W, rwsem, rwsem:R, rwsem:W, rtmutex,
           rwlock-rt, rwlock-rt:R, rwlock-rt:W, pcpu-sem, pcpu-sem:R,
           pcpu-sem:W, mutex

               Note that RW-variant of locks have :R and :W suffix.  Names without the
               suffix are shortcuts for the both variants.  Ex) rwsem = rwsem:R + rwsem:W.

       -L, --lock-filter=<value>
           Show lock contention only for given lock addresses or names
           (comma separated list).

       -S, --callstack-filter=<value>
           Show lock contention only if the callstack contains the given
           string. Note that it matches the substring so rq would match
           both raw_spin_rq_lock and irq_enter_rcu.

       -x, --field-separator=<SEP>
           Show results using a CSV-style output to make it easy to
           import directly into spreadsheets. Columns are separated by
           the string specified in SEP.

       --lock-cgroup
           Show lock contention stat by cgroup. Requires --use-bpf.

       -G, --cgroup-filter=<value>
           Show lock contention only in the given cgroups (comma
           separated list).

SEE ALSO         top

       perf(1)

COLOPHON         top

       This page is part of the perf (Performance analysis tools for
       Linux (in Linux source tree)) project.  Information about the
       project can be found at 
       ⟨https://perf.wiki.kernel.org/index.php/Main_Page⟩.  If you have a
       bug report for this manual page, send it to
       linux-kernel@vger.kernel.org.  This page was obtained from the
       project's upstream Git repository
       ⟨http://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git⟩
       on 2024-06-14.  (At that time, the date of the most recent commit
       that was found in the repository was 2024-06-13.)  If you
       discover any rendering problems in this HTML version of the page,
       or you believe there is a better or more up-to-date source for
       the page, or you have corrections or improvements to the
       information in this COLOPHON (which is not part of the original
       manual page), send a mail to man-pages@man7.org

perf                           2023-12-03                   PERF-LOCK(1)

Pages that refer to this page: perf(1)