perf: Update a stale comment

Signed-off-by: Peter Zijlstra <[email protected]>
Cc: Benjamin Herrenschmidt <[email protected]>
Cc: Frederic Weisbecker <[email protected]>
Cc: Mathieu Desnoyers <[email protected]>
Cc: Michael Ellerman <[email protected]>
Cc: Michael Neuling <[email protected]>
Cc: "Paul E. McKenney" <[email protected]>
Cc: [email protected]
Cc: Vince Weaver <[email protected]>
Cc: Victor Kaplansky <[email protected]>
Cc: Oleg Nesterov <[email protected]>
Cc: Anton Blanchard <[email protected]>
Link: http://lkml.kernel.org/n/[email protected]
Signed-off-by: Ingo Molnar <[email protected]>
This commit is contained in:
Peter Zijlstra 2013-10-31 17:41:23 +01:00 • committed by Ingo Molnar
commit 394570b793

View file

@ -85,8 +85,8 @@ again:
rb->user_page->data_head = head;
/*
* Now check if we missed an update, rely on the (compiler)
* barrier in atomic_dec_and_test() to re-read rb->head.
* Now check if we missed an update -- rely on previous implied
* compiler barriers to force a re-read.
*/
if (unlikely(head != local_read(&rb->head))) {
local_inc(&rb->nest);