summaryrefslogtreecommitdiff
path: root/kernel/sched/completion.c
diff options
context:
space:
mode:
authorLinus Torvalds <torvalds@linux-foundation.org>2017-09-04 19:10:24 +0300
committerLinus Torvalds <torvalds@linux-foundation.org>2017-09-04 19:10:24 +0300
commitf213a6c84c1b4b396a0713ee33cff0e02ba8235f (patch)
treed5c0893d171dce6b1f1cf259a0e59bf433da0839 /kernel/sched/completion.c
parent621bee34f6ed12d6d4f8896028333fc2200b4ced (diff)
parentbbdacdfed2f5fa50a2cc9f500a36e05990a0837d (diff)
downloadlinux-f213a6c84c1b4b396a0713ee33cff0e02ba8235f.tar.xz
Merge branch 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull scheduler updates from Ingo Molnar: "The main changes in this cycle were: - fix affine wakeups (Peter Zijlstra) - improve CPU onlining (and general bootup) scalability on systems with ridiculous number (thousands) of CPUs (Peter Zijlstra) - sched/numa updates (Rik van Riel) - sched/deadline updates (Byungchul Park) - sched/cpufreq enhancements and related cleanups (Viresh Kumar) - sched/debug enhancements (Xie XiuQi) - various fixes" * 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (27 commits) sched/debug: Optimize sched_domain sysctl generation sched/topology: Avoid pointless rebuild sched/topology, cpuset: Avoid spurious/wrong domain rebuilds sched/topology: Improve comments sched/topology: Fix memory leak in __sdt_alloc() sched/completion: Document that reinit_completion() must be called after complete_all() sched/autogroup: Fix error reporting printk text in autogroup_create() sched/fair: Fix wake_affine() for !NUMA_BALANCING sched/debug: Intruduce task_state_to_char() helper function sched/debug: Show task state in /proc/sched_debug sched/debug: Use task_pid_nr_ns in /proc/$pid/sched sched/core: Remove unnecessary initialization init_idle_bootup_task() sched/deadline: Change return value of cpudl_find() sched/deadline: Make find_later_rq() choose a closer CPU in topology sched/numa: Scale scan period with tasks in group and shared/private sched/numa: Slow down scan rate if shared faults dominate sched/pelt: Fix false running accounting sched: Mark pick_next_task_dl() and build_sched_domain() as static sched/cpupri: Don't re-initialize 'struct cpupri' sched/deadline: Don't re-initialize 'struct cpudl' ...
Diffstat (limited to 'kernel/sched/completion.c')
-rw-r--r--kernel/sched/completion.c8
1 files changed, 8 insertions, 0 deletions
diff --git a/kernel/sched/completion.c b/kernel/sched/completion.c
index c9524d2d9316..5d9131aa846f 100644
--- a/kernel/sched/completion.c
+++ b/kernel/sched/completion.c
@@ -47,6 +47,13 @@ EXPORT_SYMBOL(complete);
*
* 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.
+ *
+ * Since complete_all() sets the completion of @x permanently to done
+ * to allow multiple waiters to finish, a call to reinit_completion()
+ * must be used on @x if @x is to be used again. The code must make
+ * sure that all waiters have woken and finished before reinitializing
+ * @x. Also note that the function completion_done() can not be used
+ * to know if there are still waiters after complete_all() has been called.
*/
void complete_all(struct completion *x)
{
@@ -297,6 +304,7 @@ EXPORT_SYMBOL(try_wait_for_completion);
* Return: 0 if there are waiters (wait_for_completion() in progress)
* 1 if there are no waiters.
*
+ * Note, this will always return true if complete_all() was called on @X.
*/
bool completion_done(struct completion *x)
{