Re: [RFC/PATCHSET 0/6] perf tools: Support dynamic sort keys for tracepoints (v1)

[David Ahern <dsahern@gmail.com>]

On 12/14/15 10:47 AM, Arnaldo Carvalho de Melo wrote:
>> With dynamic sort keys, you can use <event.field> as a sort key.  Those
>> dynamic keys are checked and created on demand.  For instance, below is
>> to sort by next_pid field on the same data file.
>>
>>    $ perf report -s comm,sched:sched_switch.next_pid --stdio
>>    ...
>>    # Overhead  Command            next_pid
>>    # ........  ...............  ..........
>>    #
>>        21.23%  transmission-gt           0
>>        20.86%  swapper               17773
>>         6.62%  netctl-auto               0
>>         5.25%  swapper                 109
>>         5.21%  kworker/0:1H              0
>>         1.98%  Xephyr                    0
>>         1.98%  swapper                6524
>>         1.98%  swapper               27478
>>         1.37%  swapper               27476
>>         1.17%  swapper                 233
>>
>> Multiple dynamic sort keys are also supported:
>>
>>    $ perf report -s comm,sched:sched_switch.next_pid,sched:sched_switch.next_comm --stdio
>>    ...
>>    # Overhead  Command            next_pid         next_comm
>>    # ........  ...............  ..........  ................
>>    #
>>        20.86%  swapper               17773   transmission-gt
>>         9.64%  transmission-gt           0         swapper/0
>>         9.16%  transmission-gt           0         swapper/2
>>         5.25%  swapper                 109      kworker/0:1H
>>         5.21%  kworker/0:1H              0         swapper/0
>>         2.14%  netctl-auto               0         swapper/2
>>         1.98%  netctl-auto               0         swapper/0
>>         1.98%  swapper                6524            Xephyr
>>         1.98%  swapper               27478       netctl-auto
>>         1.78%  transmission-gt           0         swapper/3
>>         1.53%  Xephyr                    0         swapper/0
>>         1.29%  netctl-auto               0         swapper/1
>>         1.29%  swapper               27476       netctl-auto
>>         1.21%  netctl-auto               0         swapper/3
>>         1.17%  swapper                 233    irq/33-iwlwifi
>>
>> Note that pid 0 exists for each cpu so have comm of 'swapper/N'.
>
>> This is available on 'perf/dynamic-sort-v1' branch in my tree
>>
>>    git://git.kernel.org/pub/scm/linux/kernel/git/namhyung/linux-perf.git
>>
>> Any comments are welcome, thanks!
>> Namhyung
>
> I'll look at the patches for style, but the idea is so nice and natural
> I thought about blind merging it :-)
>

yes, that is a cool feature.

For scheduling tracepoints the analysis could be added to perf-sched to 
ease the burden of the command line syntax.