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

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?

Thanks,

- Arnaldo