Re: [PATCH -tip v3 3/6] perf branch trace: print pid and command

From: David Ahern
Date: Fri Mar 25 2011 - 11:02:21 EST


On 03/25/11 04:14, Akihiro Nagai wrote:
>> On 03/24/11 05:32, Akihiro Nagai wrote:
>>> Provide the function to print pid and command name to
>>> 'perf branch trace'. Users can select items to print with options.
>>> For example,
>>> 'perf branch -p trace' prints only pid,
>>> 'perf branch -ac trace' prints address and comamnd name.
>>> 'perf branch trace' prints only address (default)
>>>
>>> This is output sample (perf branch -ac trace):
>>> command address
>>> ls 0xffffffff8146fe0e => ls 0x0000003806200b20
>>> ls 0xffffffff8146fe0e => ls 0x0000003806200b20
>>> ls 0x0000003806200b23 => ls 0x0000003806204910
>>> ls 0xffffffff8146fe0e => ls 0x0000003806204910
>>> ls 0xffffffff8146fe0e => ls 0x0000003806204936
>>> ls 0xffffffff8146fe0e => ls 0x000000380620493d
>>> ls 0x0000003806204981 => ls 0x00000038062049a3
>>> ls 0x00000038062049a7 => ls 0x0000003806204988
>>
>> This can be easily added to perf-script. e.g,
>>
>> perf record -e branches:u -c 1 -d -- ls /tmp
>>
>> perf script -i /tmp/perf.data -f hw:comm,pid,event,sym,addr
>>
>> ...
>> ls 8150 branches: 0x39d30144d0 ffffffff8146a48e ()
>> ls 8150 branches: 0x39d3014507 ffffffff8146a48e ()
>> ls 8150 branches: 0x39d3014510 14518 _dl_sysdep_start
>> (/lib64/ld-2.13.so)
>> ...
>> ls 8150 branches: 0x39d3015250 1833 process_envvars
>> (/lib64/ld-2.13.so)
>> ls 8150 branches: 0x39d3015260 1526f _dl_next_ld_env_entry
>> (/lib64/ld-2.13.so)
>> ls 8150 branches: 0x39d3015260 1526f _dl_next_ld_env_entry
>> (/lib64/ld-2.13.so)
> It seems to analyze only 'branch from' address and,
> print 'branch to' address just in hex.
> I would like to analyze both of addresses branch from/to.

from is sample->ip? to is sample->addr? In the above example
0x39d3015260 is the value from sample->addr, 1526f is sample->ip which
resolves to _dl_next_ld_env_entry from /lib64/ld-2.13.so.

>
> Can perf-script do it by writing scripts?

If you are pulling the data from a perf sample then you can accomplish
the same goal within perf-script.


David
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