PERF-LOCK(1) | perf Manual | PERF-LOCK(1) |
NAME
perf-lock - Analyze lock events
SYNOPSIS
perf lock {record|report|script|info|contention}
DESCRIPTION
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
-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
-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
-t, --threads
dump only the thread list in perf.data
-m, --map
dump only the map of lock instances (address:name
table)
CONTENTION OPTIONS
-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
2024-06-03 | perf |