On 4 Jun 2026, at 7:47 PM, Arnaldo Carvalho de Melo [off-list ref] wrote:

On Thu, May 21, 2026 at 11:17:58AM -0300, Arnaldo Carvalho de Melo wrote:

quoted

On Thu, May 21, 2026 at 02:02:53PM +0530, Athira Rajeev wrote:

quoted

quoted

On 27 Apr 2026, at 11:26 AM, Namhyung Kim [off-list ref] wrote:
On Sun, Apr 26, 2026 at 03:09:30PM +0530, Athira Rajeev wrote:

quoted

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 <redacted>

Acked-by: Namhyung Kim <namhyung@kernel.org>

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 [off-list ref]
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 [off-list ref]
   Link: https://lore.kernel.org/r/20250716203914.45772-2-ashelat@redhat.com (local)
   Signed-off-by: Namhyung Kim [off-list ref]


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
Athira

- Arnaldo