130 lines
2.9 KiB
Plaintext
130 lines
2.9 KiB
Plaintext
perf-diff(1)
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============
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NAME
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----
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perf-diff - Read two perf.data files and display the differential profile
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SYNOPSIS
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--------
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[verse]
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'perf diff' [oldfile] [newfile]
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DESCRIPTION
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-----------
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This command displays the performance difference amongst two perf.data files
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captured via perf record.
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If no parameters are passed it will assume perf.data.old and perf.data.
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The differential profile is displayed only for events matching both
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specified perf.data files.
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OPTIONS
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-------
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-M::
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--displacement::
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Show position displacement relative to baseline.
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-D::
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--dump-raw-trace::
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Dump raw trace in ASCII.
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-m::
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--modules::
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Load module symbols. WARNING: use only with -k and LIVE kernel
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-d::
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--dsos=::
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Only consider symbols in these dsos. CSV that understands
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file://filename entries.
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-C::
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--comms=::
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Only consider symbols in these comms. CSV that understands
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file://filename entries.
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-S::
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--symbols=::
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Only consider these symbols. CSV that understands
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file://filename entries.
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-s::
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--sort=::
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Sort by key(s): pid, comm, dso, symbol.
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-t::
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--field-separator=::
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Use a special separator character and don't pad with spaces, replacing
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all occurrences of this separator in symbol names (and other output)
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with a '.' character, that thus it's the only non valid separator.
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-v::
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--verbose::
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Be verbose, for instance, show the raw counts in addition to the
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diff.
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-f::
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--force::
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Don't complain, do it.
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--symfs=<directory>::
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Look for files with symbols relative to this directory.
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-b::
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--baseline-only::
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Show only items with match in baseline.
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-c::
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--compute::
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Differential computation selection - delta,ratio,wdiff (default is delta).
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If '+' is specified as a first character, the output is sorted based
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on the computation results.
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See COMPARISON METHODS section for more info.
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COMPARISON METHODS
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------------------
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delta
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~~~~~
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If specified the 'Delta' column is displayed with value 'd' computed as:
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d = A->period_percent - B->period_percent
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with:
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- A/B being matching hist entry from first/second file specified
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(or perf.data/perf.data.old) respectively.
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- period_percent being the % of the hist entry period value within
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single data file
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ratio
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~~~~~
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If specified the 'Ratio' column is displayed with value 'r' computed as:
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r = A->period / B->period
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with:
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- A/B being matching hist entry from first/second file specified
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(or perf.data/perf.data.old) respectively.
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- period being the hist entry period value
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wdiff
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~~~~~
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If specified the 'Weighted diff' column is displayed with value 'd' computed as:
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d = B->period * WEIGHT-A - A->period * WEIGHT-B
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- A/B being matching hist entry from first/second file specified
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(or perf.data/perf.data.old) respectively.
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- period being the hist entry period value
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- WEIGHT-A/WEIGHT-B being user suplied weights in the the '-c' option
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behind ':' separator like '-c wdiff:1,2'.
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SEE ALSO
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--------
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linkperf:perf-record[1]
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