Messages in this thread | | | From | Ze Gao <> | Date | Thu, 3 Aug 2023 10:02:04 +0800 | Subject | Re: [RFC PATCH v4 4/7] sched, tracing: reorganize fields of switch event struct |
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On Wed, Aug 2, 2023 at 11:05 PM Steven Rostedt <rostedt@goodmis.org> wrote: > > On Wed, 2 Aug 2023 08:09:59 -0400 > Ze Gao <zegao2021@gmail.com> wrote: > > > From: Ze Gao <zegao2021@gmail.com> > > > > Report priorities in 'short' and prev_state in 'int' to save > > some buffer space. And also reorder the fields so that we take > > struct alignment into consideration to make the record compact. > > > > Suggested-by: Steven Rostedt (Google) <rostedt@goodmis.org> > > Signed-off-by: Ze Gao <zegao@tencent.com> > > --- > > include/trace/events/sched.h | 24 ++++++++++++------------ > > 1 file changed, 12 insertions(+), 12 deletions(-) > > > > diff --git a/include/trace/events/sched.h b/include/trace/events/sched.h > > index fbb99a61f714..7d34db20b2c6 100644 > > --- a/include/trace/events/sched.h > > +++ b/include/trace/events/sched.h > > @@ -187,7 +187,7 @@ DEFINE_EVENT(sched_wakeup_template, sched_wakeup_new, > > TP_ARGS(p)); > > > > #ifdef CREATE_TRACE_POINTS > > -static inline long __trace_sched_switch_state(bool preempt, > > +static inline int __trace_sched_switch_state(bool preempt, > > unsigned int prev_state, > > struct task_struct *p) > > { > > @@ -229,23 +229,23 @@ TRACE_EVENT(sched_switch, > > TP_ARGS(preempt, prev, next, prev_state), > > > > TP_STRUCT__entry( > > - __array( char, prev_comm, TASK_COMM_LEN ) > > __field( pid_t, prev_pid ) > > - __field( int, prev_prio ) > > - __field( long, prev_state ) > > - __array( char, next_comm, TASK_COMM_LEN ) > > __field( pid_t, next_pid ) > > - __field( int, next_prio ) > > + __field( short, prev_prio ) > > + __field( short, next_prio ) > > + __field( int, prev_state ) > > I was talking with Peter on IRC and since the biggest number that > prev_state can be is TASK_REPORT_MASK which is 0x100, I think we can make > prev_state into a short as well.
Make sense, let's change it to short.
Regards, Ze
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