linux_dsm_epyc7002/tools/perf/Documentation/perf-diff.txt
David Ahern ec5761eab3 perf symbols: Add symfs option for off-box analysis using specified tree
The symfs argument allows analysis of perf.data file using a locally accessible
filesystem tree with debug symbols - e.g., tree created during image builds,
sshfs mount, loop mounted KVM disk images, USB keys, initrds, etc. Anything
with an OS tree can be analyzed from anywhere without the need to populate a
local data store with build-ids.

Commiter notes:

o Fixed up symfs="/" variants handling.

o prefixed DSO__ORIG_GUEST_KMODULE case with symfs too, avoiding use of files
  outside the symfs directory.

LKML-Reference: <1291926427-28846-1-git-send-email-daahern@cisco.com>
Signed-off-by: David Ahern <daahern@cisco.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2010-12-21 20:17:51 -02:00

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perf-diff(1)
============
NAME
----
perf-diff - Read two perf.data files and display the differential profile
SYNOPSIS
--------
[verse]
'perf diff' [oldfile] [newfile]
DESCRIPTION
-----------
This command displays the performance difference amongst two perf.data files
captured via perf record.
If no parameters are passed it will assume perf.data.old and perf.data.
OPTIONS
-------
-M::
--displacement::
Show position displacement relative to baseline.
-D::
--dump-raw-trace::
Dump raw trace in ASCII.
-m::
--modules::
Load module symbols. WARNING: use only with -k and LIVE kernel
-d::
--dsos=::
Only consider symbols in these dsos. CSV that understands
file://filename entries.
-C::
--comms=::
Only consider symbols in these comms. CSV that understands
file://filename entries.
-S::
--symbols=::
Only consider these symbols. CSV that understands
file://filename entries.
-s::
--sort=::
Sort by key(s): pid, comm, dso, symbol.
-t::
--field-separator=::
Use a special separator character and don't pad with spaces, replacing
all occurrences of this separator in symbol names (and other output)
with a '.' character, that thus it's the only non valid separator.
-v::
--verbose::
Be verbose, for instance, show the raw counts in addition to the
diff.
-f::
--force::
Don't complain, do it.
--symfs=<directory>::
Look for files with symbols relative to this directory.
SEE ALSO
--------
linkperf:perf-record[1]