From b0b598ee08f9759b70971e297cf7ddd3eaaa5245 Mon Sep 17 00:00:00 2001 From: "Matthew Wilcox (Oracle)" Date: Tue, 10 Oct 2023 04:58:28 +0100 Subject: filemap: remove use of wait bookmarks The original problem of the overly long list of waiters on a locked page was solved properly by commit 9a1ea439b16b ("mm: put_and_wait_on_page_locked() while page is migrated"). In the meantime, using bookmarks for the writeback bit can cause livelocks, so we need to stop using them. Link: https://lkml.kernel.org/r/20231010035829.544242-1-willy@infradead.org Signed-off-by: Matthew Wilcox (Oracle) Cc: Bin Lai Cc: Benjamin Segall Cc: Daniel Bristot de Oliveira Cc: Dietmar Eggemann Cc: Ingo Molnar Cc: Juri Lelli Cc: Matthew Wilcox (Oracle) Cc: Mel Gorman Cc: Peter Zijlstra Cc: Steven Rostedt (Google) Cc: Valentin Schneider Cc: Vincent Guittot Cc: Ingo Molnar Signed-off-by: Andrew Morton --- mm/filemap.c | 21 +-------------------- 1 file changed, 1 insertion(+), 20 deletions(-) (limited to 'mm') diff --git a/mm/filemap.c b/mm/filemap.c index 48cd16c54e86..9ef49255f1a5 100644 --- a/mm/filemap.c +++ b/mm/filemap.c @@ -1133,32 +1133,13 @@ static void folio_wake_bit(struct folio *folio, int bit_nr) wait_queue_head_t *q = folio_waitqueue(folio); struct wait_page_key key; unsigned long flags; - wait_queue_entry_t bookmark; key.folio = folio; key.bit_nr = bit_nr; key.page_match = 0; - bookmark.flags = 0; - bookmark.private = NULL; - bookmark.func = NULL; - INIT_LIST_HEAD(&bookmark.entry); - spin_lock_irqsave(&q->lock, flags); - __wake_up_locked_key_bookmark(q, TASK_NORMAL, &key, &bookmark); - - while (bookmark.flags & WQ_FLAG_BOOKMARK) { - /* - * Take a breather from holding the lock, - * allow pages that finish wake up asynchronously - * to acquire the lock and remove themselves - * from wait queue - */ - spin_unlock_irqrestore(&q->lock, flags); - cpu_relax(); - spin_lock_irqsave(&q->lock, flags); - __wake_up_locked_key_bookmark(q, TASK_NORMAL, &key, &bookmark); - } + __wake_up_locked_key(q, TASK_NORMAL, &key); /* * It's possible to miss clearing waiters here, when we woke our page -- cgit