mirror of
https://github.com/torvalds/linux.git
synced 2024-11-18 01:51:53 +00:00
c351c28161
That means that almost everything you can do with 'perf report'
can be done with 'perf diff', for instance:
$ perf record -f find / > /dev/null
[ perf record: Woken up 1 times to write data ]
[ perf record: Captured and wrote 0.062 MB perf.data (~2699
samples) ] $ perf record -f find / > /dev/null
[ perf record: Woken up 1 times to write data ]
[ perf record: Captured and wrote 0.062 MB perf.data (~2687
samples) ] perf diff | head -8
9.02% +1.00% find libc-2.10.1.so [.] _IO_vfprintf_internal
2.91% -1.00% find [kernel] [k] __kmalloc
2.85% -1.00% find [kernel] [k] ext4_htree_store_dirent
1.99% -1.00% find [kernel] [k] _atomic_dec_and_lock
2.44% find [kernel] [k] half_md4_transform
$
So if you want to zoom into libc:
$ perf diff --dsos libc-2.10.1.so | head -8
37.34% find [.] _IO_vfprintf_internal
10.34% find [.] __GI_memmove
8.25% +2.00% find [.] _int_malloc
5.07% -1.00% find [.] __GI_mempcpy
7.62% +2.00% find [.] _int_free
$
And if there were multiple commands using libc, it is also
possible to aggregate them all by using --sort symbol:
$ perf diff --dsos libc-2.10.1.so --sort symbol | head -8
37.34% [.] _IO_vfprintf_internal
10.34% [.] __GI_memmove
8.25% +2.00% [.] _int_malloc
5.07% -1.00% [.] __GI_mempcpy
7.62% +2.00% [.] _int_free
$
The displacement column now is off by default, to use it:
perf diff -m --dsos libc-2.10.1.so --sort symbol | head -8
37.34% [.] _IO_vfprintf_internal
10.34% [.] __GI_memmove
8.25% +2.00% [.] _int_malloc
5.07% -1.00% +2 [.] __GI_mempcpy
7.62% +2.00% -1 [.] _int_free
$
Using -t/--field-separator can be used for scripting:
$ perf diff -t, -m --dsos libc-2.10.1.so --sort symbol | head -8
37.34, , ,[.] _IO_vfprintf_internal
10.34, , ,[.] __GI_memmove
8.25,+2.00%, ,[.] _int_malloc
5.07,-1.00%, +2,[.] __GI_mempcpy
7.62,+2.00%, -1,[.] _int_free
6.99,+1.00%, -1,[.] _IO_new_file_xsputn
1.89,-2.00%, +4,[.] __readdir64
$
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Frédéric Weisbecker <fweisbec@gmail.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
LKML-Reference: <1260978567-550-1-git-send-email-acme@infradead.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
71 lines
1.6 KiB
Plaintext
71 lines
1.6 KiB
Plaintext
perf-report(1)
|
|
==============
|
|
|
|
NAME
|
|
----
|
|
perf-report - Read perf.data (created by perf record) and display the profile
|
|
|
|
SYNOPSIS
|
|
--------
|
|
[verse]
|
|
'perf report' [-i <file> | --input=file]
|
|
|
|
DESCRIPTION
|
|
-----------
|
|
This command displays the performance counter profile information recorded
|
|
via perf record.
|
|
|
|
OPTIONS
|
|
-------
|
|
-i::
|
|
--input=::
|
|
Input file name. (default: perf.data)
|
|
-d::
|
|
--dsos=::
|
|
Only consider symbols in these dsos. CSV that understands
|
|
file://filename entries.
|
|
-n::
|
|
--show-nr-samples::
|
|
Show the number of samples for each symbol
|
|
-T::
|
|
--threads::
|
|
Show per-thread event counters
|
|
-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, parent.
|
|
|
|
-w::
|
|
--field-width=::
|
|
Force each column width to the provided list, for large terminal
|
|
readability.
|
|
|
|
-t::
|
|
--field-separator=::
|
|
|
|
Use a special separator character and don't pad with spaces, replacing
|
|
all occurances of this separator in symbol names (and other output)
|
|
with a '.' character, that thus it's the only non valid separator.
|
|
|
|
-g [type,min]::
|
|
--call-graph::
|
|
Display callchains using type and min percent threshold.
|
|
type can be either:
|
|
- flat: single column, linear exposure of callchains.
|
|
- graph: use a graph tree, displaying absolute overhead rates.
|
|
- fractal: like graph, but displays relative rates. Each branch of
|
|
the tree is considered as a new profiled object. +
|
|
Default: fractal,0.5.
|
|
|
|
SEE ALSO
|
|
--------
|
|
linkperf:perf-stat[1]
|