perf-inject - Man Page

Filter to augment the events stream with additional information


perf inject <options>


perf-inject reads a perf-record event stream and repipes it to stdout. At any point the processing code can inject other events into the event stream - in this case build-ids (-b option) are read and injected as needed into the event stream.

Build-ids are just the first user of perf-inject - potentially anything that needs userspace processing to augment the events stream with additional information could make use of this facility.


-b,  --build-ids

Inject build-ids into the output stream

--buildid-all: Inject build-ids of all DSOs into the output stream

-v,  --verbose

Be more verbose.

-i,  --input=

Input file name. (default: stdin)

-o,  --output=

Output file name. (default: stdout)

-s,  --sched-stat

Merge sched_stat and sched_switch for getting events where and how long tasks slept. sched_switch contains a callchain where a task slept and sched_stat contains a timeslice how long a task slept.

-k,  --vmlinux=<file>

vmlinux pathname


Ignore vmlinux files.


kallsyms pathname


Decode Instruction Tracing data, replacing it with synthesized events. Options are:

i       synthesize instructions events
b       synthesize branches events (branch misses for Arm SPE)
c       synthesize branches events (calls only)
r       synthesize branches events (returns only)
x       synthesize transactions events
w       synthesize ptwrite events
p       synthesize power events (incl. PSB events for Intel PT)
o       synthesize other events recorded due to the use
        of aux-output (refer to perf record)
e       synthesize error events
d       create a debug log
f       synthesize first level cache events
m       synthesize last level cache events
M       synthesize memory events
t       synthesize TLB events
a       synthesize remote access events
g       synthesize a call chain (use with i or x)
G       synthesize a call chain on existing event records
l       synthesize last branch entries (use with i or x)
L       synthesize last branch entries on existing event records
s       skip initial number of events
q       quicker (less detailed) decoding
A       approximate IPC
Z       prefer to ignore timestamps (so-called "timeless" decoding)
The default is all events i.e. the same as --itrace=ibxwpe,
except for perf script where it is --itrace=ce
In addition, the period (default 100000, except for perf script where it is 1)
for instructions events can be specified in units of:
i       instructions
t       ticks
ms      milliseconds
us      microseconds
ns      nanoseconds (default)
Also the call chain size (default 16, max. 1024) for instructions or
transactions events can be specified.
Also the number of last branch entries (default 64, max. 1024) for
instructions or transactions events can be specified.
Similar to options g and l, size may also be specified for options G and L.
On x86, note that G and L work poorly when data has been recorded with
large PEBS. Refer linkperf:perf-intel-pt[1] man page for details.
It is also possible to skip events generated (instructions, branches, transactions,
ptwrite, power) at the beginning. This is useful to ignore initialization code.
skips the first million instructions.
The 'e' option may be followed by flags which affect what errors will or
will not be reported. Each flag must be preceded by either '+' or '-'.
The flags are:
        o       overflow
        l       trace data lost
If supported, the 'd' option may be followed by flags which affect what
debug messages will or will not be logged. Each flag must be preceded
by either '+' or '-'. The flags are:
        a       all perf events
        o       output to stdout
If supported, the 'q' option may be repeated to increase the effect.

Use with --itrace to strip out non-synthesized events.

-j,  --jit

Process jitdump files by injecting the mmap records corresponding to jitted functions. This option also generates the ELF images for each jitted function found in the jitdumps files captured in the input file. Use this option if you are monitoring environment using JIT runtimes, such as Java, DART or V8.

-f,  --force

Don’t complain, do it.


Some architectures may capture AUX area data which contains timestamps affected by virtualization. This option will update those timestamps in place, to correlate with host timestamps. The in-place update means that an output file is not specified, and instead the input file is modified. The options are architecture specific, except that they may start with "dry-run" which will cause the file to be processed but without updating it. Currently this option is supported only by Intel PT, refer perf-intel-pt(1)

See Also

perf-record(1), perf-report(1), perf-archive(1), perf-intel-pt(1)

Referenced By

perf(1), perf-intel-pt(1).

01/10/2022 perf Manual