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Inject events from a perf.data file recorded in a virtual machine into a perf.data file recorded on the host at the same time. Only side band events (e.g. mmap, comm, fork, exit etc) and build IDs are injected. Additionally, the guest kcore_dir is copied as kcore_dir__ appended to the machine PID. This is non-trivial because: o It is not possible to process 2 sessions simultaneously so instead events are first written to a temporary file. o To avoid conflict, guest sample IDs are replaced with new unused sample IDs. o Guest event's CPU is changed to be the host CPU because it is more useful for reporting and analysis. o Sample ID is mapped to machine PID which is recorded with VCPU in the id index. This is important to allow guest events to be related to the guest machine and VCPU. o Timestamps must be converted. o Events are inserted to obey finished-round ordering. The anticipated use-case is: - start recording sideband events in a guest machine - start recording an AUX area trace on the host which can trace also the guest (e.g. Intel PT) - run test case on the guest - stop recording on the host - stop recording on the guest - copy the guest perf.data file to the host - inject the guest perf.data file sideband events into the host perf.data file using perf inject - the resulting perf.data file can now be used Subsequent patches provide Intel PT support for this. Signed-off-by: Adrian Hunter <adrian.hunter@intel.com> Cc: Andi Kleen <ak@linux.intel.com> Cc: Ian Rogers <irogers@google.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Namhyung Kim <namhyung@kernel.org> Cc: kvm@vger.kernel.org Link: https://lore.kernel.org/r/20220711093218.10967-25-adrian.hunter@intel.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
109 lines
3.4 KiB
Plaintext
109 lines
3.4 KiB
Plaintext
perf-inject(1)
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==============
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NAME
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----
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perf-inject - Filter to augment the events stream with additional information
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SYNOPSIS
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--------
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[verse]
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'perf inject <options>'
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DESCRIPTION
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-----------
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perf-inject reads a perf-record event stream and repipes it to stdout. At any
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point the processing code can inject other events into the event stream - in
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this case build-ids (-b option) are read and injected as needed into the event
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stream.
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Build-ids are just the first user of perf-inject - potentially anything that
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needs userspace processing to augment the events stream with additional
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information could make use of this facility.
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OPTIONS
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-------
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-b::
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--build-ids::
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Inject build-ids into the output stream
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--buildid-all:
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Inject build-ids of all DSOs into the output stream
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-v::
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--verbose::
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Be more verbose.
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-i::
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--input=::
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Input file name. (default: stdin)
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-o::
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--output=::
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Output file name. (default: stdout)
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-s::
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--sched-stat::
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Merge sched_stat and sched_switch for getting events where and how long
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tasks slept. sched_switch contains a callchain where a task slept and
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sched_stat contains a timeslice how long a task slept.
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-k::
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--vmlinux=<file>::
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vmlinux pathname
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--ignore-vmlinux::
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Ignore vmlinux files.
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--kallsyms=<file>::
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kallsyms pathname
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--itrace::
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Decode Instruction Tracing data, replacing it with synthesized events.
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Options are:
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include::itrace.txt[]
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--strip::
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Use with --itrace to strip out non-synthesized events.
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-j::
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--jit::
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Process jitdump files by injecting the mmap records corresponding to jitted
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functions. This option also generates the ELF images for each jitted function
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found in the jitdumps files captured in the input perf.data file. Use this option
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if you are monitoring environment using JIT runtimes, such as Java, DART or V8.
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-f::
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--force::
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Don't complain, do it.
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--vm-time-correlation[=OPTIONS]::
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Some architectures may capture AUX area data which contains timestamps
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affected by virtualization. This option will update those timestamps
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in place, to correlate with host timestamps. The in-place update means
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that an output file is not specified, and instead the input file is
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modified. The options are architecture specific, except that they may
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start with "dry-run" which will cause the file to be processed but
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without updating it. Currently this option is supported only by
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Intel PT, refer linkperf:perf-intel-pt[1]
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--guest-data=<path>,<pid>[,<time offset>[,<time scale>]]::
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Insert events from a perf.data file recorded in a virtual machine at
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the same time as the input perf.data file was recorded on the host.
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The Process ID (PID) of the QEMU hypervisor process must be provided,
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and the time offset and time scale (multiplier) will likely be needed
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to convert guest time stamps into host time stamps. For example, for
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x86 the TSC Offset and Multiplier could be provided for a virtual machine
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using Linux command line option no-kvmclock.
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Currently only mmap, mmap2, comm, task, context_switch, ksymbol,
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and text_poke events are inserted, as well as build ID information.
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The QEMU option -name debug-threads=on is needed so that thread names
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can be used to determine which thread is running which VCPU. Note
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libvirt seems to use this by default.
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When using perf record in the guest, option --sample-identifier
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should be used, and also --buildid-all and --switch-events may be
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useful.
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SEE ALSO
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--------
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linkperf:perf-record[1], linkperf:perf-report[1], linkperf:perf-archive[1],
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linkperf:perf-intel-pt[1]
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