epoll: add a reschedule point in ep_free()

ep_free() might iterate on a huge set of epitems and hold cpu too long.
Add two cond_resched() in order to yield cpu to other tasks.  This is safe
as we only hold mutexes in this function.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Al Viro <viro@ZenIV.linux.org.uk>
Cc: Theodore Ts'o <tytso@mit.edu>
Acked-by: Eric Wong <normalperson@yhbt.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Eric Dumazet 2013-09-11 14:24:06 -07:00 committed by Linus Torvalds
parent 8716de383b
commit 91cf5ab60f

View file

@ -740,6 +740,7 @@ static void ep_free(struct eventpoll *ep)
epi = rb_entry(rbp, struct epitem, rbn); epi = rb_entry(rbp, struct epitem, rbn);
ep_unregister_pollwait(ep, epi); ep_unregister_pollwait(ep, epi);
cond_resched();
} }
/* /*
@ -754,6 +755,7 @@ static void ep_free(struct eventpoll *ep)
while ((rbp = rb_first(&ep->rbr)) != NULL) { while ((rbp = rb_first(&ep->rbr)) != NULL) {
epi = rb_entry(rbp, struct epitem, rbn); epi = rb_entry(rbp, struct epitem, rbn);
ep_remove(ep, epi); ep_remove(ep, epi);
cond_resched();
} }
mutex_unlock(&ep->mtx); mutex_unlock(&ep->mtx);