diff options
| author | Andrea Parri <[email protected]> | 2018-07-16 11:06:03 -0700 |
|---|---|---|
| committer | Ingo Molnar <[email protected]> | 2018-07-17 09:30:34 +0200 |
| commit | 7696f9910a9a40b8a952f57d3428515fabd2d889 (patch) | |
| tree | 194b3c37bfd2a14378cb59bab3655ee6d0115cfb /kernel/sched/completion.c | |
| parent | 3d85b2703783636366560c94842affd8608ec9d1 (diff) | |
sched/Documentation: Update wake_up() & co. memory-barrier guarantees
Both the implementation and the users' expectation [1] for the various
wakeup primitives have evolved over time, but the documentation has not
kept up with these changes: brings it into 2018.
[1] http://lkml.kernel.org/r/[email protected]
Also applied feedback from Alan Stern.
Suggested-by: Peter Zijlstra <[email protected]>
Signed-off-by: Andrea Parri <[email protected]>
Signed-off-by: Paul E. McKenney <[email protected]>
Acked-by: Peter Zijlstra (Intel) <[email protected]>
Cc: Akira Yokosawa <[email protected]>
Cc: Alan Stern <[email protected]>
Cc: Boqun Feng <[email protected]>
Cc: Daniel Lustig <[email protected]>
Cc: David Howells <[email protected]>
Cc: Jade Alglave <[email protected]>
Cc: Jonathan Corbet <[email protected]>
Cc: Linus Torvalds <[email protected]>
Cc: Luc Maranget <[email protected]>
Cc: Nicholas Piggin <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: Will Deacon <[email protected]>
Cc: [email protected]
Cc: [email protected]
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Ingo Molnar <[email protected]>
Diffstat (limited to 'kernel/sched/completion.c')
| -rw-r--r-- | kernel/sched/completion.c | 8 |
1 files changed, 4 insertions, 4 deletions
diff --git a/kernel/sched/completion.c b/kernel/sched/completion.c index e426b0cb9ac6..a1ad5b7d5521 100644 --- a/kernel/sched/completion.c +++ b/kernel/sched/completion.c @@ -22,8 +22,8 @@ * * See also complete_all(), wait_for_completion() and related routines. * - * It may be assumed that this function implies a write memory barrier before - * changing the task state if and only if any tasks are woken up. + * If this function wakes up a task, it executes a full memory barrier before + * accessing the task state. */ void complete(struct completion *x) { @@ -44,8 +44,8 @@ EXPORT_SYMBOL(complete); * * This will wake up all threads waiting on this particular completion event. * - * It may be assumed that this function implies a write memory barrier before - * changing the task state if and only if any tasks are woken up. + * If this function wakes up a task, it executes a full memory barrier before + * accessing the task state. * * Since complete_all() sets the completion of @x permanently to done * to allow multiple waiters to finish, a call to reinit_completion() |