Commit f337b9c5 authored Oct 15, 2008 by Davide Libenzi Committed by Linus Torvalds Oct 16, 2008

epoll: drop unnecessary test



Thomas found that there is an unnecessary (always true) test in
ep_send_events().  The callback never inserts into ->rdllink while the
send loop is performed, and also does the ~EP_PRIVATE_BITS test.  Given
we're holding the mutex during this time, the conditions tested inside the
loop are always true.  This patch drops the test done inside the
re-insertion loop.

Signed-off-by: Davide Libenzi <davidel@xmailserver.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

parent 8b6e47ad

fs/eventpoll.c

+3 −6

Original line number	Diff line number	Diff line
		@@ -927,14 +927,11 @@ errxit:
		/*
		* During the time we spent in the loop above, some other events
		* might have been queued by the poll callback. We re-insert them
		* here (in case they are not already queued, or they're one-shot).
		* inside the main ready-list here.
		*/
		for (nepi = ep->ovflist; (epi = nepi) != NULL;
		nepi = epi->next, epi->next = EP_UNACTIVE_PTR) {
		if (!ep_is_linked(&epi->rdllink) &&
		(epi->event.events & ~EP_PRIVATE_BITS))
		nepi = epi->next, epi->next = EP_UNACTIVE_PTR)
		list_add_tail(&epi->rdllink, &ep->rdllist);
		}
		/*
		* We need to set back ep->ovflist to EP_UNACTIVE_PTR, so that after
		* releasing the lock, events will be queued in the normal way inside