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* [PATCH] perf sched timehist: decode process names of processes in zombie state
@ 2025-07-09 14:31 Anubhav Shelat
  2025-07-11 20:02 ` Namhyung Kim
  0 siblings, 1 reply; 5+ messages in thread
From: Anubhav Shelat @ 2025-07-09 14:31 UTC (permalink / raw)
  To: mpetlan, acme, namhyung, irogers, linux-perf-users
  Cc: peterz, mingo, mark.rutland, alexander.shishkin, jolsa,
	adrian.hunter, kan.liang, dapeng1.mi, james.clark, Anubhav Shelat

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 <ashelat@redhat.com>
---
 tools/perf/builtin-sched.c | 19 ++++++++++++++++---
 1 file changed, 16 insertions(+), 3 deletions(-)

diff --git a/tools/perf/builtin-sched.c b/tools/perf/builtin-sched.c
index 26ece6e9bfd1..e1a931341bc8 100644
--- a/tools/perf/builtin-sched.c
+++ b/tools/perf/builtin-sched.c
@@ -2023,11 +2023,15 @@ static int comm_width = 30;
 static char *timehist_get_commstr(struct thread *thread)
 {
 	static char str[32];
-	const char *comm = thread__comm_str(thread);
+	char *comm = (char *) thread__comm_str(thread);
+	char *empty = (char *) "";
 	pid_t tid = thread__tid(thread);
 	pid_t pid = thread__pid(thread);
 	int n;
 
+	if (*comm == ':')
+		comm = empty;
+
 	if (pid == 0)
 		n = scnprintf(str, sizeof(str), "%s", comm);
 
@@ -2147,6 +2151,8 @@ static void timehist_print_sample(struct perf_sched *sched,
 	struct thread_runtime *tr = thread__priv(thread);
 	const char *next_comm = evsel__strval(evsel, sample, "next_comm");
 	const u32 next_pid = evsel__intval(evsel, sample, "next_pid");
+	const char *prev_comm = evsel__strval(evsel, sample, "prev_comm");
+	char *comm_str = timehist_get_commstr(thread);
 	u32 max_cpus = sched->max_cpu.cpu + 1;
 	char tstr[64];
 	char nstr[30];
@@ -2173,8 +2179,15 @@ static void timehist_print_sample(struct perf_sched *sched,
 		}
 		printf(" ");
 	}
-
-	printf(" %-*s ", comm_width, timehist_get_commstr(thread));
+	
+	/* if a process is in zombie state commstr will start with a '[' and 
+	 * we need to do extra processing to decode the process name */
+	if (*comm_str == '[') {
+		printf(" %s", evsel__strval(evsel, sample, "prev_comm"));
+		printf("%-*s ", comm_width - (int) strlen(prev_comm), comm_str);
+	}
+	else
+		printf(" %-*s ", comm_width, comm_str);
 
 	if (sched->show_prio)
 		printf(" %-*s ", MAX_PRIO_STR_LEN, timehist_get_priostr(evsel, thread, sample));
-- 
2.50.0


^ permalink raw reply related	[flat|nested] 5+ messages in thread

* Re: [PATCH] perf sched timehist: decode process names of processes in zombie state
  2025-07-09 14:31 [PATCH] perf sched timehist: decode process names of processes in zombie state Anubhav Shelat
@ 2025-07-11 20:02 ` Namhyung Kim
  2025-07-15 15:59   ` Anubhav Shelat
  0 siblings, 1 reply; 5+ messages in thread
From: Namhyung Kim @ 2025-07-11 20:02 UTC (permalink / raw)
  To: Anubhav Shelat
  Cc: mpetlan, acme, irogers, linux-perf-users, peterz, mingo,
	mark.rutland, alexander.shishkin, jolsa, adrian.hunter, kan.liang,
	dapeng1.mi, james.clark

Hello,

On Wed, Jul 09, 2025 at 10:31:20AM -0400, Anubhav Shelat wrote:
> 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

Thanks for the fix.  A nitpick below.

> 
> Signed-off-by: Anubhav Shelat <ashelat@redhat.com>
> ---
>  tools/perf/builtin-sched.c | 19 ++++++++++++++++---
>  1 file changed, 16 insertions(+), 3 deletions(-)
> 
> diff --git a/tools/perf/builtin-sched.c b/tools/perf/builtin-sched.c
> index 26ece6e9bfd1..e1a931341bc8 100644
> --- a/tools/perf/builtin-sched.c
> +++ b/tools/perf/builtin-sched.c
> @@ -2023,11 +2023,15 @@ static int comm_width = 30;
>  static char *timehist_get_commstr(struct thread *thread)
>  {
>  	static char str[32];
> -	const char *comm = thread__comm_str(thread);
> +	char *comm = (char *) thread__comm_str(thread);
> +	char *empty = (char *) "";
>  	pid_t tid = thread__tid(thread);
>  	pid_t pid = thread__pid(thread);
>  	int n;
>  
> +	if (*comm == ':')
> +		comm = empty;
> +
>  	if (pid == 0)
>  		n = scnprintf(str, sizeof(str), "%s", comm);
>  
> @@ -2147,6 +2151,8 @@ static void timehist_print_sample(struct perf_sched *sched,
>  	struct thread_runtime *tr = thread__priv(thread);
>  	const char *next_comm = evsel__strval(evsel, sample, "next_comm");
>  	const u32 next_pid = evsel__intval(evsel, sample, "next_pid");
> +	const char *prev_comm = evsel__strval(evsel, sample, "prev_comm");
> +	char *comm_str = timehist_get_commstr(thread);
>  	u32 max_cpus = sched->max_cpu.cpu + 1;
>  	char tstr[64];
>  	char nstr[30];
> @@ -2173,8 +2179,15 @@ static void timehist_print_sample(struct perf_sched *sched,
>  		}
>  		printf(" ");
>  	}
> -
> -	printf(" %-*s ", comm_width, timehist_get_commstr(thread));
> +	
> +	/* if a process is in zombie state commstr will start with a '[' and 
> +	 * we need to do extra processing to decode the process name */
> +	if (*comm_str == '[') {
> +		printf(" %s", evsel__strval(evsel, sample, "prev_comm"));
> +		printf("%-*s ", comm_width - (int) strlen(prev_comm), comm_str);
> +	}
> +	else
> +		printf(" %-*s ", comm_width, comm_str);

What about just updating thread comm if it's missing?

	if (!thread__comm_set(thread)) {
		const char *prev_comm = evsel__strval(evsel, sample, "prev_comm");
		thread__set_comm(thread, prev_comm, sample->time);
	}
	
	printf(" %-%s ", comm_width, timehist_get_commstr(thread));

Thanks,
Namhyung

>  
>  	if (sched->show_prio)
>  		printf(" %-*s ", MAX_PRIO_STR_LEN, timehist_get_priostr(evsel, thread, sample));
> -- 
> 2.50.0
> 

^ permalink raw reply	[flat|nested] 5+ messages in thread

* Re: [PATCH] perf sched timehist: decode process names of processes in zombie state
  2025-07-11 20:02 ` Namhyung Kim
@ 2025-07-15 15:59   ` Anubhav Shelat
  2025-07-16 19:36     ` Namhyung Kim
  0 siblings, 1 reply; 5+ messages in thread
From: Anubhav Shelat @ 2025-07-15 15:59 UTC (permalink / raw)
  To: Namhyung Kim
  Cc: mpetlan, acme, irogers, linux-perf-users, peterz, mingo,
	mark.rutland, alexander.shishkin, jolsa, adrian.hunter, kan.liang,
	dapeng1.mi, james.clark

When I tried to build, it threw the error:

builtin-sched.c: In function ‘timehist_print_sample’:
builtin-sched.c:2186:29: error: declaration of ‘prev_comm’ shadows a
previous local [-Werror=shadow]
 2186 |                 const char *prev_comm = evsel__strval(evsel,
sample, "prev_comm");
      |                             ^~~~~~~~~
builtin-sched.c:2154:21: note: shadowed declaration is here
 2154 |         const char *prev_comm = evsel__strval(evsel, sample,
"prev_comm");
      |                     ^~~~~~~~~
builtin-sched.c:2154:21: error: unused variable ‘prev_comm’
[-Werror=unused-variable]


Anubhav

On Fri, Jul 11, 2025 at 4:02 PM Namhyung Kim <namhyung@kernel.org> wrote:
>
> Hello,
>
> On Wed, Jul 09, 2025 at 10:31:20AM -0400, Anubhav Shelat wrote:
> > 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
>
> Thanks for the fix.  A nitpick below.
>
> >
> > Signed-off-by: Anubhav Shelat <ashelat@redhat.com>
> > ---
> >  tools/perf/builtin-sched.c | 19 ++++++++++++++++---
> >  1 file changed, 16 insertions(+), 3 deletions(-)
> >
> > diff --git a/tools/perf/builtin-sched.c b/tools/perf/builtin-sched.c
> > index 26ece6e9bfd1..e1a931341bc8 100644
> > --- a/tools/perf/builtin-sched.c
> > +++ b/tools/perf/builtin-sched.c
> > @@ -2023,11 +2023,15 @@ static int comm_width = 30;
> >  static char *timehist_get_commstr(struct thread *thread)
> >  {
> >       static char str[32];
> > -     const char *comm = thread__comm_str(thread);
> > +     char *comm = (char *) thread__comm_str(thread);
> > +     char *empty = (char *) "";
> >       pid_t tid = thread__tid(thread);
> >       pid_t pid = thread__pid(thread);
> >       int n;
> >
> > +     if (*comm == ':')
> > +             comm = empty;
> > +
> >       if (pid == 0)
> >               n = scnprintf(str, sizeof(str), "%s", comm);
> >
> > @@ -2147,6 +2151,8 @@ static void timehist_print_sample(struct perf_sched *sched,
> >       struct thread_runtime *tr = thread__priv(thread);
> >       const char *next_comm = evsel__strval(evsel, sample, "next_comm");
> >       const u32 next_pid = evsel__intval(evsel, sample, "next_pid");
> > +     const char *prev_comm = evsel__strval(evsel, sample, "prev_comm");
> > +     char *comm_str = timehist_get_commstr(thread);
> >       u32 max_cpus = sched->max_cpu.cpu + 1;
> >       char tstr[64];
> >       char nstr[30];
> > @@ -2173,8 +2179,15 @@ static void timehist_print_sample(struct perf_sched *sched,
> >               }
> >               printf(" ");
> >       }
> > -
> > -     printf(" %-*s ", comm_width, timehist_get_commstr(thread));
> > +
> > +     /* if a process is in zombie state commstr will start with a '[' and
> > +      * we need to do extra processing to decode the process name */
> > +     if (*comm_str == '[') {
> > +             printf(" %s", evsel__strval(evsel, sample, "prev_comm"));
> > +             printf("%-*s ", comm_width - (int) strlen(prev_comm), comm_str);
> > +     }
> > +     else
> > +             printf(" %-*s ", comm_width, comm_str);
>
> What about just updating thread comm if it's missing?
>
>         if (!thread__comm_set(thread)) {
>                 const char *prev_comm = evsel__strval(evsel, sample, "prev_comm");
>                 thread__set_comm(thread, prev_comm, sample->time);
>         }
>
>         printf(" %-%s ", comm_width, timehist_get_commstr(thread));
>
> Thanks,
> Namhyung
>
> >
> >       if (sched->show_prio)
> >               printf(" %-*s ", MAX_PRIO_STR_LEN, timehist_get_priostr(evsel, thread, sample));
> > --
> > 2.50.0
> >
>


^ permalink raw reply	[flat|nested] 5+ messages in thread

* Re: [PATCH] perf sched timehist: decode process names of processes in zombie state
  2025-07-15 15:59   ` Anubhav Shelat
@ 2025-07-16 19:36     ` Namhyung Kim
  2025-07-16 20:38       ` Anubhav Shelat
  0 siblings, 1 reply; 5+ messages in thread
From: Namhyung Kim @ 2025-07-16 19:36 UTC (permalink / raw)
  To: Anubhav Shelat
  Cc: mpetlan, acme, irogers, linux-perf-users, peterz, mingo,
	mark.rutland, alexander.shishkin, jolsa, adrian.hunter, kan.liang,
	dapeng1.mi, james.clark

On Tue, Jul 15, 2025 at 11:59:29AM -0400, Anubhav Shelat wrote:
> When I tried to build, it threw the error:
> 
> builtin-sched.c: In function ‘timehist_print_sample’:
> builtin-sched.c:2186:29: error: declaration of ‘prev_comm’ shadows a
> previous local [-Werror=shadow]
>  2186 |                 const char *prev_comm = evsel__strval(evsel,
> sample, "prev_comm");
>       |                             ^~~~~~~~~
> builtin-sched.c:2154:21: note: shadowed declaration is here
>  2154 |         const char *prev_comm = evsel__strval(evsel, sample,
> "prev_comm");
>       |                     ^~~~~~~~~
> builtin-sched.c:2154:21: error: unused variable ‘prev_comm’
> [-Werror=unused-variable]

Yep, you need to delete the old code.

Thanks,
Namhyung

> 
> On Fri, Jul 11, 2025 at 4:02 PM Namhyung Kim <namhyung@kernel.org> wrote:
> >
> > Hello,
> >
> > On Wed, Jul 09, 2025 at 10:31:20AM -0400, Anubhav Shelat wrote:
> > > 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
> >
> > Thanks for the fix.  A nitpick below.
> >
> > >
> > > Signed-off-by: Anubhav Shelat <ashelat@redhat.com>
> > > ---
> > >  tools/perf/builtin-sched.c | 19 ++++++++++++++++---
> > >  1 file changed, 16 insertions(+), 3 deletions(-)
> > >
> > > diff --git a/tools/perf/builtin-sched.c b/tools/perf/builtin-sched.c
> > > index 26ece6e9bfd1..e1a931341bc8 100644
> > > --- a/tools/perf/builtin-sched.c
> > > +++ b/tools/perf/builtin-sched.c
> > > @@ -2023,11 +2023,15 @@ static int comm_width = 30;
> > >  static char *timehist_get_commstr(struct thread *thread)
> > >  {
> > >       static char str[32];
> > > -     const char *comm = thread__comm_str(thread);
> > > +     char *comm = (char *) thread__comm_str(thread);
> > > +     char *empty = (char *) "";
> > >       pid_t tid = thread__tid(thread);
> > >       pid_t pid = thread__pid(thread);
> > >       int n;
> > >
> > > +     if (*comm == ':')
> > > +             comm = empty;
> > > +
> > >       if (pid == 0)
> > >               n = scnprintf(str, sizeof(str), "%s", comm);
> > >
> > > @@ -2147,6 +2151,8 @@ static void timehist_print_sample(struct perf_sched *sched,
> > >       struct thread_runtime *tr = thread__priv(thread);
> > >       const char *next_comm = evsel__strval(evsel, sample, "next_comm");
> > >       const u32 next_pid = evsel__intval(evsel, sample, "next_pid");
> > > +     const char *prev_comm = evsel__strval(evsel, sample, "prev_comm");
> > > +     char *comm_str = timehist_get_commstr(thread);
> > >       u32 max_cpus = sched->max_cpu.cpu + 1;
> > >       char tstr[64];
> > >       char nstr[30];
> > > @@ -2173,8 +2179,15 @@ static void timehist_print_sample(struct perf_sched *sched,
> > >               }
> > >               printf(" ");
> > >       }
> > > -
> > > -     printf(" %-*s ", comm_width, timehist_get_commstr(thread));
> > > +
> > > +     /* if a process is in zombie state commstr will start with a '[' and
> > > +      * we need to do extra processing to decode the process name */
> > > +     if (*comm_str == '[') {
> > > +             printf(" %s", evsel__strval(evsel, sample, "prev_comm"));
> > > +             printf("%-*s ", comm_width - (int) strlen(prev_comm), comm_str);
> > > +     }
> > > +     else
> > > +             printf(" %-*s ", comm_width, comm_str);
> >
> > What about just updating thread comm if it's missing?
> >
> >         if (!thread__comm_set(thread)) {
> >                 const char *prev_comm = evsel__strval(evsel, sample, "prev_comm");
> >                 thread__set_comm(thread, prev_comm, sample->time);
> >         }
> >
> >         printf(" %-%s ", comm_width, timehist_get_commstr(thread));
> >
> > Thanks,
> > Namhyung
> >
> > >
> > >       if (sched->show_prio)
> > >               printf(" %-*s ", MAX_PRIO_STR_LEN, timehist_get_priostr(evsel, thread, sample));
> > > --
> > > 2.50.0
> > >
> >
> 

^ permalink raw reply	[flat|nested] 5+ messages in thread

* Re: [PATCH] perf sched timehist: decode process names of processes in zombie state
  2025-07-16 19:36     ` Namhyung Kim
@ 2025-07-16 20:38       ` Anubhav Shelat
  0 siblings, 0 replies; 5+ messages in thread
From: Anubhav Shelat @ 2025-07-16 20:38 UTC (permalink / raw)
  To: Namhyung Kim
  Cc: mpetlan, acme, irogers, linux-perf-users, peterz, mingo,
	mark.rutland, alexander.shishkin, jolsa, adrian.hunter, kan.liang,
	dapeng1.mi, james.clark

Yep you're right. Sending it now.

Thanks,
Anubhav

On Wed, Jul 16, 2025 at 3:36 PM Namhyung Kim <namhyung@kernel.org> wrote:
>
> On Tue, Jul 15, 2025 at 11:59:29AM -0400, Anubhav Shelat wrote:
> > When I tried to build, it threw the error:
> >
> > builtin-sched.c: In function ‘timehist_print_sample’:
> > builtin-sched.c:2186:29: error: declaration of ‘prev_comm’ shadows a
> > previous local [-Werror=shadow]
> >  2186 |                 const char *prev_comm = evsel__strval(evsel,
> > sample, "prev_comm");
> >       |                             ^~~~~~~~~
> > builtin-sched.c:2154:21: note: shadowed declaration is here
> >  2154 |         const char *prev_comm = evsel__strval(evsel, sample,
> > "prev_comm");
> >       |                     ^~~~~~~~~
> > builtin-sched.c:2154:21: error: unused variable ‘prev_comm’
> > [-Werror=unused-variable]
>
> Yep, you need to delete the old code.
>
> Thanks,
> Namhyung
>
> >
> > On Fri, Jul 11, 2025 at 4:02 PM Namhyung Kim <namhyung@kernel.org> wrote:
> > >
> > > Hello,
> > >
> > > On Wed, Jul 09, 2025 at 10:31:20AM -0400, Anubhav Shelat wrote:
> > > > 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
> > >
> > > Thanks for the fix.  A nitpick below.
> > >
> > > >
> > > > Signed-off-by: Anubhav Shelat <ashelat@redhat.com>
> > > > ---
> > > >  tools/perf/builtin-sched.c | 19 ++++++++++++++++---
> > > >  1 file changed, 16 insertions(+), 3 deletions(-)
> > > >
> > > > diff --git a/tools/perf/builtin-sched.c b/tools/perf/builtin-sched.c
> > > > index 26ece6e9bfd1..e1a931341bc8 100644
> > > > --- a/tools/perf/builtin-sched.c
> > > > +++ b/tools/perf/builtin-sched.c
> > > > @@ -2023,11 +2023,15 @@ static int comm_width = 30;
> > > >  static char *timehist_get_commstr(struct thread *thread)
> > > >  {
> > > >       static char str[32];
> > > > -     const char *comm = thread__comm_str(thread);
> > > > +     char *comm = (char *) thread__comm_str(thread);
> > > > +     char *empty = (char *) "";
> > > >       pid_t tid = thread__tid(thread);
> > > >       pid_t pid = thread__pid(thread);
> > > >       int n;
> > > >
> > > > +     if (*comm == ':')
> > > > +             comm = empty;
> > > > +
> > > >       if (pid == 0)
> > > >               n = scnprintf(str, sizeof(str), "%s", comm);
> > > >
> > > > @@ -2147,6 +2151,8 @@ static void timehist_print_sample(struct perf_sched *sched,
> > > >       struct thread_runtime *tr = thread__priv(thread);
> > > >       const char *next_comm = evsel__strval(evsel, sample, "next_comm");
> > > >       const u32 next_pid = evsel__intval(evsel, sample, "next_pid");
> > > > +     const char *prev_comm = evsel__strval(evsel, sample, "prev_comm");
> > > > +     char *comm_str = timehist_get_commstr(thread);
> > > >       u32 max_cpus = sched->max_cpu.cpu + 1;
> > > >       char tstr[64];
> > > >       char nstr[30];
> > > > @@ -2173,8 +2179,15 @@ static void timehist_print_sample(struct perf_sched *sched,
> > > >               }
> > > >               printf(" ");
> > > >       }
> > > > -
> > > > -     printf(" %-*s ", comm_width, timehist_get_commstr(thread));
> > > > +
> > > > +     /* if a process is in zombie state commstr will start with a '[' and
> > > > +      * we need to do extra processing to decode the process name */
> > > > +     if (*comm_str == '[') {
> > > > +             printf(" %s", evsel__strval(evsel, sample, "prev_comm"));
> > > > +             printf("%-*s ", comm_width - (int) strlen(prev_comm), comm_str);
> > > > +     }
> > > > +     else
> > > > +             printf(" %-*s ", comm_width, comm_str);
> > >
> > > What about just updating thread comm if it's missing?
> > >
> > >         if (!thread__comm_set(thread)) {
> > >                 const char *prev_comm = evsel__strval(evsel, sample, "prev_comm");
> > >                 thread__set_comm(thread, prev_comm, sample->time);
> > >         }
> > >
> > >         printf(" %-%s ", comm_width, timehist_get_commstr(thread));
> > >
> > > Thanks,
> > > Namhyung
> > >
> > > >
> > > >       if (sched->show_prio)
> > > >               printf(" %-*s ", MAX_PRIO_STR_LEN, timehist_get_priostr(evsel, thread, sample));
> > > > --
> > > > 2.50.0
> > > >
> > >
> >
>


^ permalink raw reply	[flat|nested] 5+ messages in thread

end of thread, other threads:[~2025-07-16 20:38 UTC | newest]

Thread overview: 5+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2025-07-09 14:31 [PATCH] perf sched timehist: decode process names of processes in zombie state Anubhav Shelat
2025-07-11 20:02 ` Namhyung Kim
2025-07-15 15:59   ` Anubhav Shelat
2025-07-16 19:36     ` Namhyung Kim
2025-07-16 20:38       ` Anubhav Shelat

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