summaryrefslogtreecommitdiff
path: root/kernel/sched
diff options
context:
space:
mode:
authorMatthew Wilcox (Oracle) <willy@infradead.org>2023-10-10 06:58:29 +0300
committerAndrew Morton <akpm@linux-foundation.org>2023-10-19 00:34:18 +0300
commit37acade0ce8938f00d6979bd02b8043b5b7089ae (patch)
tree5f7b973798dce9f7f0fee84457f215a208e6470e /kernel/sched
parentb0b598ee08f9759b70971e297cf7ddd3eaaa5245 (diff)
downloadlinux-37acade0ce8938f00d6979bd02b8043b5b7089ae.tar.xz
sched: remove wait bookmarks
There are no users of wait bookmarks left, so simplify the wait code by removing them. Link: https://lkml.kernel.org/r/20231010035829.544242-2-willy@infradead.org Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Acked-by: Ingo Molnar <mingo@kernel.org> Cc: Benjamin Segall <bsegall@google.com> Cc: Bin Lai <sclaibin@gmail.com> Cc: Daniel Bristot de Oliveira <bristot@redhat.com> Cc: Dietmar Eggemann <dietmar.eggemann@arm.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Juri Lelli <juri.lelli@redhat.com> Cc: Mel Gorman <mgorman@suse.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Steven Rostedt (Google) <rostedt@goodmis.org> Cc: Valentin Schneider <vschneid@redhat.com> Cc: Vincent Guittot <vincent.guittot@linaro.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Diffstat (limited to 'kernel/sched')
-rw-r--r--kernel/sched/wait.c60
1 files changed, 10 insertions, 50 deletions
diff --git a/kernel/sched/wait.c b/kernel/sched/wait.c
index 802d98cf2de3..51e38f5f4701 100644
--- a/kernel/sched/wait.c
+++ b/kernel/sched/wait.c
@@ -58,13 +58,6 @@ void remove_wait_queue(struct wait_queue_head *wq_head, struct wait_queue_entry
EXPORT_SYMBOL(remove_wait_queue);
/*
- * Scan threshold to break wait queue walk.
- * This allows a waker to take a break from holding the
- * wait queue lock during the wait queue walk.
- */
-#define WAITQUEUE_WALK_BREAK_CNT 64
-
-/*
* The core wakeup function. Non-exclusive wakeups (nr_exclusive == 0) just
* wake everything up. If it's an exclusive wakeup (nr_exclusive == small +ve
* number) then we wake that number of exclusive tasks, and potentially all
@@ -78,21 +71,13 @@ EXPORT_SYMBOL(remove_wait_queue);
* zero in this (rare) case, and we handle it by continuing to scan the queue.
*/
static int __wake_up_common(struct wait_queue_head *wq_head, unsigned int mode,
- int nr_exclusive, int wake_flags, void *key,
- wait_queue_entry_t *bookmark)
+ int nr_exclusive, int wake_flags, void *key)
{
wait_queue_entry_t *curr, *next;
- int cnt = 0;
lockdep_assert_held(&wq_head->lock);
- if (bookmark && (bookmark->flags & WQ_FLAG_BOOKMARK)) {
- curr = list_next_entry(bookmark, entry);
-
- list_del(&bookmark->entry);
- bookmark->flags = 0;
- } else
- curr = list_first_entry(&wq_head->head, wait_queue_entry_t, entry);
+ curr = list_first_entry(&wq_head->head, wait_queue_entry_t, entry);
if (&curr->entry == &wq_head->head)
return nr_exclusive;
@@ -101,21 +86,11 @@ static int __wake_up_common(struct wait_queue_head *wq_head, unsigned int mode,
unsigned flags = curr->flags;
int ret;
- if (flags & WQ_FLAG_BOOKMARK)
- continue;
-
ret = curr->func(curr, mode, wake_flags, key);
if (ret < 0)
break;
if (ret && (flags & WQ_FLAG_EXCLUSIVE) && !--nr_exclusive)
break;
-
- if (bookmark && (++cnt > WAITQUEUE_WALK_BREAK_CNT) &&
- (&next->entry != &wq_head->head)) {
- bookmark->flags = WQ_FLAG_BOOKMARK;
- list_add_tail(&bookmark->entry, &next->entry);
- break;
- }
}
return nr_exclusive;
@@ -125,20 +100,12 @@ static int __wake_up_common_lock(struct wait_queue_head *wq_head, unsigned int m
int nr_exclusive, int wake_flags, void *key)
{
unsigned long flags;
- wait_queue_entry_t bookmark;
- int remaining = nr_exclusive;
+ int remaining;
- bookmark.flags = 0;
- bookmark.private = NULL;
- bookmark.func = NULL;
- INIT_LIST_HEAD(&bookmark.entry);
-
- do {
- spin_lock_irqsave(&wq_head->lock, flags);
- remaining = __wake_up_common(wq_head, mode, remaining,
- wake_flags, key, &bookmark);
- spin_unlock_irqrestore(&wq_head->lock, flags);
- } while (bookmark.flags & WQ_FLAG_BOOKMARK);
+ spin_lock_irqsave(&wq_head->lock, flags);
+ remaining = __wake_up_common(wq_head, mode, nr_exclusive, wake_flags,
+ key);
+ spin_unlock_irqrestore(&wq_head->lock, flags);
return nr_exclusive - remaining;
}
@@ -171,23 +138,16 @@ void __wake_up_on_current_cpu(struct wait_queue_head *wq_head, unsigned int mode
*/
void __wake_up_locked(struct wait_queue_head *wq_head, unsigned int mode, int nr)
{
- __wake_up_common(wq_head, mode, nr, 0, NULL, NULL);
+ __wake_up_common(wq_head, mode, nr, 0, NULL);
}
EXPORT_SYMBOL_GPL(__wake_up_locked);
void __wake_up_locked_key(struct wait_queue_head *wq_head, unsigned int mode, void *key)
{
- __wake_up_common(wq_head, mode, 1, 0, key, NULL);
+ __wake_up_common(wq_head, mode, 1, 0, key);
}
EXPORT_SYMBOL_GPL(__wake_up_locked_key);
-void __wake_up_locked_key_bookmark(struct wait_queue_head *wq_head,
- unsigned int mode, void *key, wait_queue_entry_t *bookmark)
-{
- __wake_up_common(wq_head, mode, 1, 0, key, bookmark);
-}
-EXPORT_SYMBOL_GPL(__wake_up_locked_key_bookmark);
-
/**
* __wake_up_sync_key - wake up threads blocked on a waitqueue.
* @wq_head: the waitqueue
@@ -233,7 +193,7 @@ EXPORT_SYMBOL_GPL(__wake_up_sync_key);
void __wake_up_locked_sync_key(struct wait_queue_head *wq_head,
unsigned int mode, void *key)
{
- __wake_up_common(wq_head, mode, 1, WF_SYNC, key, NULL);
+ __wake_up_common(wq_head, mode, 1, WF_SYNC, key);
}
EXPORT_SYMBOL_GPL(__wake_up_locked_sync_key);