perf-lock(1) — Linux manual page

NAME \| SYNOPSIS \| DESCRIPTION \| COMMON OPTIONS \| REPORT OPTIONS \| INFO OPTIONS \| 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)

       -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

.ft C
-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::
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=::
Record events on existing process ID (comma separated list).

--tid=::
Record events on existing thread ID (comma separated list).

--map-nr-entries::
Maximum number of BPF map entries (default: 10240).

--max-stack::
Maximum stack depth when collecting lock contention (default: 8).

--stack-skip
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

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 2022-12-17.  (At that time, the date of the most recent commit
       that was found in the repository was 2022-12-16.)  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                           2022-12-14                   PERF-LOCK(1)

Pages that refer to this page: perf(1)