> On 4 Jun 2026, at 8:56 PM, Arnaldo Carvalho de Melo <[email protected]> wrote:
>
> On Thu, Jun 04, 2026 at 08:38:46PM +0530, Athira Rajeev wrote:
>>> On 4 Jun 2026, at 7:47 PM, Arnaldo Carvalho de Melo <[email protected]> wrote:
>>>
>>> On Thu, May 21, 2026 at 11:17:58AM -0300, Arnaldo Carvalho de Melo wrote:
>>>> On Thu, May 21, 2026 at 02:02:53PM +0530, Athira Rajeev wrote:
>>>>>> On 27 Apr 2026, at 11:26 AM, Namhyung Kim <[email protected]> wrote:
>>>>>> On Sun, Apr 26, 2026 at 03:09:30PM +0530, Athira Rajeev wrote:
>>>>>>> In redhat perftool testsuite, observed fail for this test:
>>>>>>> -- [ FAIL ] -- perf_sched :: test_timehist :: --with-summary (output
>>>>>>> regexp parsing)
>>>>>>>
>>>>>>> This led to analysis of "perf sched timehist" summary options.
>>>>>>>
>>>>>>> # perf sched record -a -o ./perf.data -- sleep 0.1
>>>>>>> This will record using perf sched record
>>>>>>>
>>>>>>> perf sched timeliest has two options "-s" and "-S"
>>>>>>> # perf sched -i ./perf.data timehist -S
>>>>>>> -S : Captures summary also at the end
>>>>>>>
>>>>>>> # perf sched -i ./perf.data timehist -s
>>>>>>> -s : Captures only summary
>>>>>>>
>>>>>>> The test saves -s result which has only summary and compares with
>>>>>>> summary which comes at the end from -S . Since there is a difference
>>>>>>> in these two, test fails.
>>>>>>>
>>>>>>> Checking the behaviour change in -S and -s results, difference is:
>>>>>>>
>>>>>>> rcu_sched[16] 2 4 0.013 0.001
>>>>>>> 0.003 0.006 33.23 0
>>>>>>> migration/11[73] 2 1 0.006 0.006
>>>>>>> 0.006 0.006 0.00 0
>>>>>>> migration/3[33] 2 1 0.006 0.006
>>>>>>> 0.006 0.006 0.00 0
>>>>>>> - :216753[216753] -1 1 0.041
>>>>>>> 0.041 0.041 0.041 0.00 0
>>>>>>> + sleep[216753] -1 1 0.041
>>>>>>> 0.041 0.041 0.041 0.00 0
>>>>>>> migration/8[58] 2 1 0.005 0.005
>>>>>>> 0.005 0.005 0.00 0
>>>>>>> NetworkManager[811] 1 2 0.089 0.028
>>>>>>> 0.044 0.060 36.06 0
>>>>>>> migration/13[83] 2 1 0.005 0.005
>>>>>>> 0.005 0.005 0.00 0
>>>>>>>
>>>>>>> Here 216753 is pid for sleep which is a zombie process. This is
>>>>>>> happening in latest kernel due to an update in "-S" result.
>>>>>>> In -S, the process name appears in the results "sleep[216753]",
>>>>>>> where as in the -s, only pid is present in the summary result
>>>>>>> ":216753[216753]".
>>>>>>>
>>>>>>> After commit 39f473f6d0b2 ("perf sched timehist: decode process names
>>>>>>> of processes in zombie state")
>>>>>>> for -S option, if process name is using pid, it uses different way to
>>>>>>> set it. So that we get the process name and not just Pid.
>>>>>>>
>>>>>>> This change went in only for timehist_print_sample() function.
>>>>>>> Add this improvement in generic place so that even -s option (which
>>>>>>> captures summary) also will have meaningful information.
>>>>>>>
>>>>>>> Signed-off-by: Athira Rajeev <[email protected]>
>>>>>>
>>>>>> Acked-by: Namhyung Kim <[email protected]>
>>>>>>
>>>>>> Thanks,
>>>>>> Namhyung
>>>>> Hi,
>>>>>
>>>>> Can we please have this pulled in, if the patch looks fine ?
>>>>
>>>> Can you please check applying it on top of current perf-tools-next?
>>>
>>> So, this seems to be also addressed by:
>>>
>>> commit 39f473f6d0b24cf375893f2110b1cc9d8a079a42
>>> Author: Anubhav Shelat <[email protected]>
>>> Date: Wed Jul 16 16:39:15 2025 -0400
>>>
>>> perf sched timehist: decode process names of processes in zombie state
>>>
>>> Previously when running perf trace timehist --state, when recording
>>> processes in the zombie state the process name would not be decoded
>>> properly and appears with just the PID:
>>>
>>> 1140057.412177 [0006] Mutter Input Th[3139/3104] 0.956
>>> 0.019 0.041 S
>>> 1140057.412222 [0012] :1248612[1248612] 0.000
>>> 0.000 0.332 Z
>>> 1140057.412275 [0004] <idle> 0.052
>>> 0.052 0.953 I
>>> 1140057.412284 [0008] <idle> 0.070
>>> 0.070 0.932 I
>>> 1140057.412333 [0004] KMS thread[3126/3104] 0.953
>>> 0.112 0.058 S
>>>
>>> Now some extra processing has been added to decode the process name:
>>>
>>> 1140057.412177 [0006] Mutter Input Th[3139/3104] 0.956
>>> 0.019 0.041 S
>>> 1140057.412222 [0012] sleep[1248612] 0.000
>>> 0.000 0.332 Z
>>> 1140057.412275 [0004] <idle> 0.052
>>> 0.052 0.953 I
>>> 1140057.412284 [0008] <idle> 0.070
>>> 0.070 0.932 I
>>> 1140057.412333 [0004] KMS thread[3126/3104] 0.953
>>> 0.112 0.058 S
>>>
>>> Signed-off-by: Anubhav Shelat <[email protected]>
>>> Link: https://lore.kernel.org/r/[email protected]
>>> Signed-off-by: Namhyung Kim <[email protected]>
>>>
>>>
>>> No? It is not applying to perf-tools-next, a quick look found the patch
>>> above.
>>
>> Hi Arnaldo
>>
>> commit 39f473f6d0b2 ("perf sched timehist: decode process names
>> of processes in zombie state”)
>> added change for -S option. The patch I submitted is to add change in
>> process name for “-s” option as well
>>
>> I will check applying this on top of current perf-tools-next
>
> Thanks for looking into this!
>
> - Arnaldo
Hi Arnaldo
I have posted rebased patch on top of perf-tools-next here :
https://lore.kernel.org/linux-perf-users/[email protected]/
Thanks
Athira
