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NAME | SYNOPSIS | DESCRIPTION | COMMON OPTIONS | REPORT OPTIONS | INFO OPTIONS | CONTENTION OPTIONS | SEE ALSO | COLOPHON |
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PERF-LOCK(1) perf Manual PERF-LOCK(1)
perf-lock - Analyze lock events
perf lock {record|report|script|info|contention}
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.
-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
-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.
-t, --threads
dump thread list in perf.data
-m, --map
dump map of lock instances (address:name table)
-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).
perf(1)
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
[email protected]. 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 [email protected]
perf 2023-12-03 PERF-LOCK(1)
Pages that refer to this page: perf(1)
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HTML rendering created 2024-06-26 by Michael Kerrisk, author of The Linux Programming Interface. For details of in-depth Linux/UNIX system programming training courses that I teach, look here. Hosting by jambit GmbH. |
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