Messages in this thread Patch in this message | | | From | Roman Penyaev <> | Subject | [PATCH 2/3] epoll: loosen irq safety in ep_poll_callback() | Date | Wed, 12 Dec 2018 12:03:56 +0100 |
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Callers of the ep_poll_callback() (all set of wake_up_*poll()) disable interrupts, so no need to save/restore irq flags.
Signed-off-by: Roman Penyaev <rpenyaev@suse.de> Cc: Davidlohr Bueso <dbueso@suse.de> Cc: Jason Baron <jbaron@akamai.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: linux-fsdevel@vger.kernel.org Cc: linux-kernel@vger.kernel.org --- fs/eventpoll.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-)
diff --git a/fs/eventpoll.c b/fs/eventpoll.c index 3627c2e07149..ea0025e77519 100644 --- a/fs/eventpoll.c +++ b/fs/eventpoll.c @@ -1124,13 +1124,15 @@ struct file *get_epoll_tfile_raw_ptr(struct file *file, int tfd, static int ep_poll_callback(wait_queue_entry_t *wait, unsigned mode, int sync, void *key) { int pwake = 0; - unsigned long flags; struct epitem *epi = ep_item_from_wait(wait); struct eventpoll *ep = epi->ep; __poll_t pollflags = key_to_poll(key); int ewake = 0; - spin_lock_irqsave(&ep->wq.lock, flags); + /* Interrupts are disabled by the wake_up_*poll() callers */ + lockdep_assert_irqs_disabled(); + + spin_lock(&ep->wq.lock); ep_set_busy_poll_napi_id(epi); @@ -1207,7 +1209,7 @@ static int ep_poll_callback(wait_queue_entry_t *wait, unsigned mode, int sync, v pwake++; out_unlock: - spin_unlock_irqrestore(&ep->wq.lock, flags); + spin_unlock(&ep->wq.lock); /* We have to call this outside the lock */ if (pwake) -- 2.19.1
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