Re: [PATCH 6/8] perf tools: Add new comm infrastructure

From: Frederic Weisbecker
Date: Mon Oct 28 2013 - 05:09:52 EST


2013/10/28 Namhyung Kim <namhyung@xxxxxxxxxx>:
> Hi David,
>
> On Fri, 25 Oct 2013 12:19:07 -0600, David Ahern wrote:
>> On 10/25/13 12:12 PM, Frederic Weisbecker wrote:
>>> Oh I see. It's possible that my massive conversion to use the comm
>>> accessor got blind at some point and left over a few things. I
>>> remember that I only lightly tested that new comm infrastructure. I
>>> mean I tested a lot of "perf report -s foo,bar" combinations for
>>> performance comparisons but I haven't tested the perf script and all
>>> the other perf tools.
>>>
>>> I'll rebase these patches and test that wider before resending.
>>
>> specifically, I see stuff like perf forking ls and comm still shows as
>> perf even though there is COMM record with the rename to ls. I believe
>> the test case was something like:
>>
>> perf sched record -- ls
>> perf script
>
> Hmm.. did you try my latest v5 patchset? I couldn't reproduce the case
> at least for the command lines above.
>
> $ perf script
> perf 24810 [007] 1546517.815809: sched:sched_stat_runtime: comm=perf pid=24810 ru
> perf 24810 [007] 1546517.815909: sched:sched_wakeup: comm=perf pid=24811 prio=120
> swapper 0 [008] 1546517.815913: sched:sched_switch: prev_comm=swapper/8 prev_pid
> perf 24810 [007] 1546517.815953: sched:sched_stat_runtime: comm=perf pid=24810 ru
> perf 24810 [007] 1546517.815957: sched:sched_switch: prev_comm=perf prev_pid=2481
> perf 24811 [008] 1546517.815992: sched:sched_wakeup: comm=migration/8 pid=48 prio
> perf 24811 [008] 1546517.815993: sched:sched_stat_runtime: comm=perf pid=24811 ru
> perf 24811 [008] 1546517.815993: sched:sched_switch: prev_comm=perf prev_pid=2481
> migration/8 48 [008] 1546517.815996: sched:sched_migrate_task: comm=perf pid=24811 pr
> migration/8 48 [008] 1546517.816000: sched:sched_switch: prev_comm=migration/8 prev_p
> swapper 0 [009] 1546517.816002: sched:sched_switch: prev_comm=swapper/9 prev_pid
> ls 24811 [009] 1546517.816808: sched:sched_stat_runtime: comm=ls pid=24811 runt
>
>
> Here, the process 24811 has only 3 samples before COMM event
>
> $ perf report -D | grep 24811 | grep -v MMAP | head
> 0 0 0x629b0 [0x38]: PERF_RECORD_COMM: perf:24811
> 8 1546517815992058 0x65f50 [0x68]: PERF_RECORD_SAMPLE(IP, 1): 24811/24811: 0xffffffff81091512 period: 1 addr: 0
> ... thread: perf:24811
> 8 1546517815993189 0x65fb8 [0x70]: PERF_RECORD_SAMPLE(IP, 1): 24811/24811: 0xffffffff81099d25 period: 83314 addr: 0
> ... thread: perf:24811
> 8 1546517815993975 0x66028 [0x80]: PERF_RECORD_SAMPLE(IP, 1): 24811/24811: 0xffffffff81659d60 period: 1 addr: 0
> ... thread: perf:24811
> 9 1546517816224342 0x66378 [0x38]: PERF_RECORD_COMM: ls:24811
> 9 1546517816808637 0x667f0 [0x70]: PERF_RECORD_SAMPLE(IP, 1): 24811/24811: 0xffffffff81099d25 period: 810663 addr: 0
> ... thread: ls:24811
>
> $ perf version
> perf version 3.11.ge9eb20
>

Ah cool! Could you please remind me the name of that branch so that I
can do some tests and work on top of it?

Thanks.
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