Re: [RFC PATCH v3 4/6] sched, tracing: reorganize fields of switch event struct
From: Steven Rostedt <rostedt@goodmis.org>
Date: 2023-08-01 14:16:22
Also in:
linux-perf-users, lkml
On Tue, 1 Aug 2023 17:01:22 +0800 Ze Gao [off-list ref] wrote:
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 <redacted>
I'd swap this patch with patch 3. That is, make the field changes first. I'd like this to get in regardless of if the state_char is accepted. We may want to get this in first to see if there's any regressions before we add a state_char. -- Steve
quoted hunk ↗ jump to hunk
--- include/trace/events/sched.h | 22 +++++++++++----------- 1 file changed, 11 insertions(+), 11 deletions(-)diff --git a/include/trace/events/sched.h b/include/trace/events/sched.h index e507901bcab8..36863ffb00c6 100644 --- a/include/trace/events/sched.h +++ b/include/trace/events/sched.h@@ -188,7 +188,7 @@ 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) {@@ -251,25 +251,25 @@ 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 ) - __field( char, prev_state_char ) - __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 ) + __array( char, prev_comm, TASK_COMM_LEN ) + __array( char, next_comm, TASK_COMM_LEN ) + __field( char, prev_state_char ) ), TP_fast_assign( - memcpy(__entry->next_comm, next->comm, TASK_COMM_LEN); __entry->prev_pid = prev->pid; - __entry->prev_prio = prev->prio; + __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); __entry->prev_state_char = __trace_sched_switch_state_char(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 */ ),