[055/127] latencytop: fix per task accumulator

[Greg KH]

2.6.32-stable review patch.  If anyone has any objections, please let us know.

------------------

From: Ken Chen <kenchen@xxxxxxxxxx>

commit 38715258aa2e8cd94bd4aafadc544e5104efd551 upstream.

Per task latencytop accumulator prematurely terminates due to erroneous
placement of latency_record_count.  It should be incremented whenever a
new record is allocated instead of increment on every latencytop event.

Also fix search iterator to only search known record events instead of
blindly searching all pre-allocated space.

Signed-off-by: Ken Chen <kenchen@xxxxxxxxxx>
Reviewed-by: Arjan van de Ven <arjan@xxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxx>

---
 kernel/latencytop.c |   17 ++++++++---------
 1 file changed, 8 insertions(+), 9 deletions(-)

--- a/kernel/latencytop.c
+++ b/kernel/latencytop.c
@@ -195,14 +195,7 @@ __account_scheduler_latency(struct task_
 
 	account_global_scheduler_latency(tsk, &lat);
 
-	/*
-	 * short term hack; if we're > 32 we stop; future we recycle:
-	 */
-	tsk->latency_record_count++;
-	if (tsk->latency_record_count >= LT_SAVECOUNT)
-		goto out_unlock;
-
-	for (i = 0; i < LT_SAVECOUNT; i++) {
+	for (i = 0; i < tsk->latency_record_count; i++) {
 		struct latency_record *mylat;
 		int same = 1;
 
@@ -228,8 +221,14 @@ __account_scheduler_latency(struct task_
 		}
 	}
 
+	/*
+	 * short term hack; if we're > 32 we stop; future we recycle:
+	 */
+	if (tsk->latency_record_count >= LT_SAVECOUNT)
+		goto out_unlock;
+
 	/* Allocated a new one: */
-	i = tsk->latency_record_count;
+	i = tsk->latency_record_count++;
 	memcpy(&tsk->latency_record[i], &lat, sizeof(struct latency_record));
 
 out_unlock:


--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/