perf: split perf_trace_buf_prepare into alloc and update parts

split allows to move expensive update of 'struct trace_entry' to later phase.
Repurpose unused 1st argument of perf_tp_event() to indicate event type.

While splitting use temp variable 'rctx' instead of '*rctx' to avoid
unnecessary loads done by the compiler due to -fno-strict-aliasing

Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 4 insertions, 2 deletions

diff --git a/kernel/events/core.c b/kernel/events/core.c
index de24fbce5277..d8512883c0a0 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -6987,7 +6987,7 @@ static int perf_tp_event_match(struct perf_event *event,
 	return 1;
 }
 
-void perf_tp_event(u64 addr, u64 count, void *record, int entry_size,
+void perf_tp_event(u16 event_type, u64 count, void *record, int entry_size,
 		   struct pt_regs *regs, struct hlist_head *head, int rctx,
 		   struct task_struct *task)
 {
@@ -6999,9 +6999,11 @@ void perf_tp_event(u64 addr, u64 count, void *record, int entry_size,
 		.data = record,
 	};
 
-	perf_sample_data_init(&data, addr, 0);
+	perf_sample_data_init(&data, 0, 0);
 	data.raw = &raw;
 
+	perf_trace_buf_update(record, event_type);
+
 	hlist_for_each_entry_rcu(event, head, hlist_entry) {
 		if (perf_tp_event_match(event, &data, regs))
 			perf_swevent_event(event, count, &data, regs);