[RFC,2/4] rcu: remove trace_rcu_kvfree_callback

Commit Message

Vlastimil Babka Jan. 23, 2025, 10:37 a.m. UTC

Tree RCU does not handle kvfree_rcu() by queueing individual objects by
call_rcu() anymore, thus the tracepoint and associated
__is_kvfree_rcu_offset() check is dead code now. Remove it.

Signed-off-by: Vlastimil Babka <[e-mail]>
---
 include/trace/events/rcu.h | 34 ----------------------------------
 kernel/rcu/tree.c          |  9 ++-------
 2 files changed, 2 insertions(+), 41 deletions(-)

Patch

diff --git a/include/trace/events/rcu.h b/include/trace/events/rcu.h
index e81431deaa50b21725b08ad7c1a2992a0074065a..ac3b28b8939b78843aecb44bed8cb76c451ab060 100644
--- a/include/trace/events/rcu.h
+++ b/include/trace/events/rcu.h
@@ -560,40 +560,6 @@  TRACE_EVENT_RCU(rcu_segcb_stats,
 
 );
 
-/*
- * Tracepoint for the registration of a single RCU callback of the special
- * kvfree() form.  The first argument is the RCU type, the second argument
- * is a pointer to the RCU callback, the third argument is the offset
- * of the callback within the enclosing RCU-protected data structure,
- * the fourth argument is the number of lazy callbacks queued, and the
- * fifth argument is the total number of callbacks queued.
- */
-TRACE_EVENT_RCU(rcu_kvfree_callback,
-
-	TP_PROTO(const char *rcuname, struct rcu_head *rhp, unsigned long offset,
-		 long qlen),
-
-	TP_ARGS(rcuname, rhp, offset, qlen),
-
-	TP_STRUCT__entry(
-		__field(const char *, rcuname)
-		__field(void *, rhp)
-		__field(unsigned long, offset)
-		__field(long, qlen)
-	),
-
-	TP_fast_assign(
-		__entry->rcuname = rcuname;
-		__entry->rhp = rhp;
-		__entry->offset = offset;
-		__entry->qlen = qlen;
-	),
-
-	TP_printk("%s rhp=%p func=%ld %ld",
-		  __entry->rcuname, __entry->rhp, __entry->offset,
-		  __entry->qlen)
-);
-
 /*
  * Tracepoint for marking the beginning rcu_do_batch, performed to start
  * RCU callback invocation.  The first argument is the RCU flavor,
diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c
index 6af042cde9727c8d7f7e3d88f26ba222d0d9c535..f3d5a9caebd9d0772931725bee93c1e172f8b6da 100644
--- a/kernel/rcu/tree.c
+++ b/kernel/rcu/tree.c
@@ -2932,13 +2932,8 @@  static int __init rcu_spawn_core_kthreads(void)
 static void rcutree_enqueue(struct rcu_data *rdp, struct rcu_head *head, rcu_callback_t func)
 {
 	rcu_segcblist_enqueue(&rdp->cblist, head);
-	if (__is_kvfree_rcu_offset((unsigned long)func))
-		trace_rcu_kvfree_callback(rcu_state.name, head,
-					 (unsigned long)func,
-					 rcu_segcblist_n_cbs(&rdp->cblist));
-	else
-		trace_rcu_callback(rcu_state.name, head,
-				   rcu_segcblist_n_cbs(&rdp->cblist));
+	trace_rcu_callback(rcu_state.name, head,
+			   rcu_segcblist_n_cbs(&rdp->cblist));
 	trace_rcu_segcb_stats(&rdp->cblist, TPS("SegCBQueued"));
 }