* [PATCH] tracing/sched: add 'next_policy' to trace_sched_switch
@ 2025-08-22 10:51 Xiang Gao
2025-08-22 14:02 ` Steven Rostedt
0 siblings, 1 reply; 3+ messages in thread
From: Xiang Gao @ 2025-08-22 10:51 UTC (permalink / raw)
To: rostedt, mhiramat
Cc: mathieu.desnoyers, andrii, mingo, oleg, akpm, gmonaco,
ricardo.neri-calderon, libo.chen, linux-kernel,
linux-trace-kernel, gaoxiang17
From: gaoxiang17 <gaoxiang17@xiaomi.com>
Sometimes, when analyzing some real-time process issues, it is necessary to know the sched policy.
Show up in the trace as:
113.457176: sched_switch: prev_comm=kcompactd0 prev_pid=30 prev_prio=120 prev_state=S ==> next_comm=kworker/u4:1 next_pid=27 next_prio=120 next_policy=0
113.457282: sched_switch: prev_comm=kworker/u4:1 prev_pid=27 prev_prio=120 prev_state=I ==> next_comm=swapper/0 next_pid=0 next_prio=120 next_policy=0
113.461166: sched_switch: prev_comm=swapper/0 prev_pid=0 prev_prio=120 prev_state=R ==> next_comm=kworker/u4:1 next_pid=27 next_prio=120 next_policy=0
Signed-off-by: gaoxiang17 <gaoxiang17@xiaomi.com>
---
include/trace/events/sched.h | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)
diff --git a/include/trace/events/sched.h b/include/trace/events/sched.h
index 7b2645b50e78..b416b7bafee4 100644
--- a/include/trace/events/sched.h
+++ b/include/trace/events/sched.h
@@ -234,6 +234,7 @@ TRACE_EVENT(sched_switch,
__array( char, next_comm, TASK_COMM_LEN )
__field( pid_t, next_pid )
__field( int, next_prio )
+ __field( unsigned int, next_policy )
),
TP_fast_assign(
@@ -244,10 +245,11 @@ TRACE_EVENT(sched_switch,
memcpy(__entry->next_comm, next->comm, TASK_COMM_LEN);
__entry->next_pid = next->pid;
__entry->next_prio = next->prio;
+ __entry->next_policy = next->policy;
/* XXX SCHED_DEADLINE */
),
- TP_printk("prev_comm=%s prev_pid=%d prev_prio=%d prev_state=%s%s ==> next_comm=%s next_pid=%d next_prio=%d",
+ TP_printk("prev_comm=%s prev_pid=%d prev_prio=%d prev_state=%s%s ==> next_comm=%s next_pid=%d next_prio=%d next_policy=%u",
__entry->prev_comm, __entry->prev_pid, __entry->prev_prio,
(__entry->prev_state & (TASK_REPORT_MAX - 1)) ?
@@ -263,7 +265,7 @@ TRACE_EVENT(sched_switch,
"R",
__entry->prev_state & TASK_REPORT_MAX ? "+" : "",
- __entry->next_comm, __entry->next_pid, __entry->next_prio)
+ __entry->next_comm, __entry->next_pid, __entry->next_prio, __entry->next_policy)
);
/*
--
2.34.1
^ permalink raw reply related [flat|nested] 3+ messages in thread
* Re: [PATCH] tracing/sched: add 'next_policy' to trace_sched_switch
2025-08-22 10:51 [PATCH] tracing/sched: add 'next_policy' to trace_sched_switch Xiang Gao
@ 2025-08-22 14:02 ` Steven Rostedt
2025-08-22 14:04 ` Steven Rostedt
0 siblings, 1 reply; 3+ messages in thread
From: Steven Rostedt @ 2025-08-22 14:02 UTC (permalink / raw)
To: Xiang Gao
Cc: mhiramat, mathieu.desnoyers, andrii, mingo, oleg, akpm, gmonaco,
ricardo.neri-calderon, libo.chen, linux-kernel,
linux-trace-kernel, gaoxiang17
On Fri, 22 Aug 2025 18:51:13 +0800
Xiang Gao <gxxa03070307@gmail.com> wrote:
> From: gaoxiang17 <gaoxiang17@xiaomi.com>
>
> Sometimes, when analyzing some real-time process issues, it is necessary to know the sched policy.
>
> Show up in the trace as:
>
> 113.457176: sched_switch: prev_comm=kcompactd0 prev_pid=30 prev_prio=120 prev_state=S ==> next_comm=kworker/u4:1 next_pid=27 next_prio=120 next_policy=0
> 113.457282: sched_switch: prev_comm=kworker/u4:1 prev_pid=27 prev_prio=120 prev_state=I ==> next_comm=swapper/0 next_pid=0 next_prio=120 next_policy=0
> 113.461166: sched_switch: prev_comm=swapper/0 prev_pid=0 prev_prio=120 prev_state=R ==> next_comm=kworker/u4:1 next_pid=27 next_prio=120 next_policy=0
>
> Signed-off-by: gaoxiang17 <gaoxiang17@xiaomi.com>
> ---
> include/trace/events/sched.h | 6 ++++--
> 1 file changed, 4 insertions(+), 2 deletions(-)
>
> diff --git a/include/trace/events/sched.h b/include/trace/events/sched.h
> index 7b2645b50e78..b416b7bafee4 100644
> --- a/include/trace/events/sched.h
> +++ b/include/trace/events/sched.h
> @@ -234,6 +234,7 @@ TRACE_EVENT(sched_switch,
> __array( char, next_comm, TASK_COMM_LEN )
> __field( pid_t, next_pid )
> __field( int, next_prio )
> + __field( unsigned int, next_policy )
> ),
>
> TP_fast_assign(
> @@ -244,10 +245,11 @@ TRACE_EVENT(sched_switch,
> memcpy(__entry->next_comm, next->comm, TASK_COMM_LEN);
> __entry->next_pid = next->pid;
> __entry->next_prio = next->prio;
> + __entry->next_policy = next->policy;
> /* XXX SCHED_DEADLINE */
> ),
>
> - TP_printk("prev_comm=%s prev_pid=%d prev_prio=%d prev_state=%s%s ==> next_comm=%s next_pid=%d next_prio=%d",
> + TP_printk("prev_comm=%s prev_pid=%d prev_prio=%d prev_state=%s%s ==> next_comm=%s next_pid=%d next_prio=%d next_policy=%u",
> __entry->prev_comm, __entry->prev_pid, __entry->prev_prio,
>
> (__entry->prev_state & (TASK_REPORT_MAX - 1)) ?
> @@ -263,7 +265,7 @@ TRACE_EVENT(sched_switch,
> "R",
>
> __entry->prev_state & TASK_REPORT_MAX ? "+" : "",
> - __entry->next_comm, __entry->next_pid, __entry->next_prio)
> + __entry->next_comm, __entry->next_pid, __entry->next_prio, __entry->next_policy)
I'm fine with this change, but I'm not sure how Peter feels about updating
scheduler tracepoints. That said, why not show the policy name?
TP_printk("prev_comm=%s prev_pid=%d prev_prio=%d prev_state=%s%s ==> next_comm=%s next_pid=%d next_prio=%d next_policy=%s",
[..]
__entry->next_comm, __entry->next_pid, __entry->next_prio,
__print_symbolic(__entry->next_policy,
{ SCHED_NORMAL, "normal" },
{ SCHED_FIFO, "FIFO" },
{ SCHED_RR, "RR" },
{ SCHED_BATCH, "batch" },
{ SCHED_IDLE, "idle" },
{ SCHED_DEADLINE, "deadline" },
{ SCHED_EXT, "sched_ext"}))
-- Steve
> );
>
> /*
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH] tracing/sched: add 'next_policy' to trace_sched_switch
2025-08-22 14:02 ` Steven Rostedt
@ 2025-08-22 14:04 ` Steven Rostedt
0 siblings, 0 replies; 3+ messages in thread
From: Steven Rostedt @ 2025-08-22 14:04 UTC (permalink / raw)
To: Xiang Gao
Cc: mhiramat, mathieu.desnoyers, andrii, mingo, oleg, akpm, gmonaco,
ricardo.neri-calderon, libo.chen, linux-kernel,
linux-trace-kernel, gaoxiang17, Peter Zijlstra, Ingo Molnar,
Juri Lelli, Vincent Guittot
[ Adding scheduler maintainers ]
On Fri, 22 Aug 2025 10:02:09 -0400
Steven Rostedt <rostedt@goodmis.org> wrote:
> On Fri, 22 Aug 2025 18:51:13 +0800
> Xiang Gao <gxxa03070307@gmail.com> wrote:
>
> > From: gaoxiang17 <gaoxiang17@xiaomi.com>
> >
> > Sometimes, when analyzing some real-time process issues, it is necessary to know the sched policy.
> >
> > Show up in the trace as:
> >
> > 113.457176: sched_switch: prev_comm=kcompactd0 prev_pid=30 prev_prio=120 prev_state=S ==> next_comm=kworker/u4:1 next_pid=27 next_prio=120 next_policy=0
> > 113.457282: sched_switch: prev_comm=kworker/u4:1 prev_pid=27 prev_prio=120 prev_state=I ==> next_comm=swapper/0 next_pid=0 next_prio=120 next_policy=0
> > 113.461166: sched_switch: prev_comm=swapper/0 prev_pid=0 prev_prio=120 prev_state=R ==> next_comm=kworker/u4:1 next_pid=27 next_prio=120 next_policy=0
> >
> > Signed-off-by: gaoxiang17 <gaoxiang17@xiaomi.com>
> > ---
> > include/trace/events/sched.h | 6 ++++--
> > 1 file changed, 4 insertions(+), 2 deletions(-)
> >
> > diff --git a/include/trace/events/sched.h b/include/trace/events/sched.h
> > index 7b2645b50e78..b416b7bafee4 100644
> > --- a/include/trace/events/sched.h
> > +++ b/include/trace/events/sched.h
> > @@ -234,6 +234,7 @@ TRACE_EVENT(sched_switch,
> > __array( char, next_comm, TASK_COMM_LEN )
> > __field( pid_t, next_pid )
> > __field( int, next_prio )
> > + __field( unsigned int, next_policy )
> > ),
> >
> > TP_fast_assign(
> > @@ -244,10 +245,11 @@ TRACE_EVENT(sched_switch,
> > memcpy(__entry->next_comm, next->comm, TASK_COMM_LEN);
> > __entry->next_pid = next->pid;
> > __entry->next_prio = next->prio;
> > + __entry->next_policy = next->policy;
> > /* XXX SCHED_DEADLINE */
> > ),
> >
> > - TP_printk("prev_comm=%s prev_pid=%d prev_prio=%d prev_state=%s%s ==> next_comm=%s next_pid=%d next_prio=%d",
> > + TP_printk("prev_comm=%s prev_pid=%d prev_prio=%d prev_state=%s%s ==> next_comm=%s next_pid=%d next_prio=%d next_policy=%u",
> > __entry->prev_comm, __entry->prev_pid, __entry->prev_prio,
> >
> > (__entry->prev_state & (TASK_REPORT_MAX - 1)) ?
> > @@ -263,7 +265,7 @@ TRACE_EVENT(sched_switch,
> > "R",
> >
> > __entry->prev_state & TASK_REPORT_MAX ? "+" : "",
> > - __entry->next_comm, __entry->next_pid, __entry->next_prio)
> > + __entry->next_comm, __entry->next_pid, __entry->next_prio, __entry->next_policy)
>
>
> I'm fine with this change, but I'm not sure how Peter feels about updating
> scheduler tracepoints. That said, why not show the policy name?
Oh, and trace events are owned by the subsystem maintainers not the tracing
maintainers. You need to Cc them.
-- Steve
>
> TP_printk("prev_comm=%s prev_pid=%d prev_prio=%d prev_state=%s%s ==> next_comm=%s next_pid=%d next_prio=%d next_policy=%s",
> [..]
> __entry->next_comm, __entry->next_pid, __entry->next_prio,
> __print_symbolic(__entry->next_policy,
> { SCHED_NORMAL, "normal" },
> { SCHED_FIFO, "FIFO" },
> { SCHED_RR, "RR" },
> { SCHED_BATCH, "batch" },
> { SCHED_IDLE, "idle" },
> { SCHED_DEADLINE, "deadline" },
> { SCHED_EXT, "sched_ext"}))
>
> -- Steve
>
>
>
>
>
>
> > );
> >
> > /*
>
^ permalink raw reply [flat|nested] 3+ messages in thread
end of thread, other threads:[~2025-08-22 14:04 UTC | newest]
Thread overview: 3+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2025-08-22 10:51 [PATCH] tracing/sched: add 'next_policy' to trace_sched_switch Xiang Gao
2025-08-22 14:02 ` Steven Rostedt
2025-08-22 14:04 ` Steven Rostedt
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).