forked from luck/tmp_suning_uos_patched
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>
56 lines
1.1 KiB
Plaintext
56 lines
1.1 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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OPTIONS
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-------
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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 occurances 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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SEE ALSO
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--------
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linkperf:perf-record[1]
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