table of contents
| PERF-INJECT(1) | perf Manual | PERF-INJECT(1) |
NAME¶
perf-inject - Filter to augment the events stream with additional information
SYNOPSIS¶
perf inject <options>
DESCRIPTION¶
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.
OPTIONS¶
-b, --build-ids
Inject build-ids of DSOs hit by samples into the output
stream. This means it needs to process all SAMPLE records to find the
DSOs.
--buildid-all
Inject build-ids of all DSOs into the output stream
regardless of hits and skip SAMPLE processing.
--known-build-ids=
Override build-ids to inject using these comma-separated
pairs of build-id and path. Understands file://filename to read these
pairs from a file, which can be generated with perf buildid-list.
-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
Ignore vmlinux files.
--kallsyms=<file>
kallsyms pathname
--itrace
Decode Instruction Tracing data, replacing it with
synthesized events. Options are:
i synthesize instructions events y synthesize cycles 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) I synthesize interrupt or similar (asynchronous) events
(e.g. Intel PT Event Trace) 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=iybxwpe, 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.
--itrace=i0nss1000000
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
e output only on errors (size configurable - see linkperf:perf-config[1])
o output to stdout
If supported, the 'q' option may be repeated to increase the effect.
--strip
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
perf.data 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.
--vm-time-correlation[=OPTIONS]
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)
--guest-data=<path>,<pid>[,<time offset>[,<time scale>]]
Insert events from a perf.data file recorded in a virtual
machine at the same time as the input perf.data file was recorded on the host.
The Process ID (PID) of the QEMU hypervisor process must be provided, and the
time offset and time scale (multiplier) will likely be needed to convert guest
time stamps into host time stamps. For example, for x86 the TSC Offset and
Multiplier could be provided for a virtual machine using Linux command line
option no-kvmclock. Currently only mmap, mmap2, comm, task, context_switch,
ksymbol, and text_poke events are inserted, as well as build ID information.
The QEMU option -name debug-threads=on is needed so that thread names can be
used to determine which thread is running which VCPU. Note libvirt seems to
use this by default. When using perf record in the guest, option
--sample-identifier should be used, and also --buildid-all and --switch-events
may be useful.
--guestmount=<path>
Guest OS root file system mount directory. Users mount
guest OS root directories under <path> by a specific filesystem access
method, typically, sshfs. For example, start 2 guest OS, one’s pid is
8888 and the other’s is 9999:
$ mkdir ~/guestmount $ cd ~/guestmount $ sshfs -o allow_other,direct_io -p 5551 localhost:/ 8888/ $ sshfs -o allow_other,direct_io -p 5552 localhost:/ 9999/ $ perf inject --guestmount=~/guestmount
SEE ALSO¶
perf-record(1), perf-report(1), perf-archive(1), perf-intel-pt(1)
| 06/15/2024 | perf |