On Wed, 2 Aug 2023 08:09:59 -0400
Ze Gao <zegao2021@xxxxxxxxx> wrote:
> From: Ze Gao <zegao2021@xxxxxxxxx>
>
> 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@xxxxxxxxxxx>
> Signed-off-by: Ze Gao <zegao@xxxxxxxxxxx>
> ---
> 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.
-- Steve
> + __array( char, prev_comm, TASK_COMM_LEN )
> + __array( char, next_comm, TASK_COMM_LEN )
> ),
>
> TP_fast_assign(
> - memcpy(__entry->next_comm, next->comm, TASK_COMM_LEN);
> - __entry->prev_pid = prev->pid;
> - __entry->prev_prio = prev->prio;
> - __entry->prev_state = __trace_sched_switch_state(preempt, prev_state, prev);
> + __entry->prev_pid = prev->pid;
> + __entry->next_pid = next->pid;
> + __entry->prev_prio = (short) prev->prio;
> + __entry->next_prio = (short) next->prio;
> + __entry->prev_state = __trace_sched_switch_state(preempt, prev_state, prev);
> memcpy(__entry->prev_comm, prev->comm, TASK_COMM_LEN);
> - __entry->next_pid = next->pid;
> - __entry->next_prio = next->prio;
> + memcpy(__entry->next_comm, next->comm, TASK_COMM_LEN);
> /* XXX SCHED_DEADLINE */
> ),
>
|