Messages in this thread Patch in this message | | | Date | Fri, 04 Sep 2009 17:13:37 -0700 | From | Greg KH <> | Subject | [patch 02/71] poll/select: initialize triggered field of struct poll_wqueues |
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2.6.30-stable review patch. If anyone has any objections, please let us know.
------------------ From: Guillaume Knispel <gknispel@proformatique.com>
commit b2add73dbf93fd50f00564d7abc3e2b9aa9dd20c upstream.
The triggered field of struct poll_wqueues introduced in commit 5f820f648c92a5ecc771a96b3c29aa6e90013bba ("poll: allow f_op->poll to sleep").
It was first set to 1 in pollwake() (now __pollwake() ), tested and later set to 0 in poll_schedule_timeout(), but not initialized before.
As a result when the process needs to sleep, triggered was likely to be non-zero even if pollwake() is not called before the first poll_schedule_timeout(), meaning schedule_hrtimeout_range() would not be called and an extra loop calling all ->poll() would be done.
This patch initialize triggered to 0 in poll_initwait() so the ->poll() are not called twice before the process goes to sleep when it needs to.
Signed-off-by: Guillaume Knispel <gknispel@proformatique.com> Acked-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Tejun Heo <tj@kernel.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
--- fs/select.c | 1 + 1 file changed, 1 insertion(+)
--- a/fs/select.c +++ b/fs/select.c @@ -110,6 +110,7 @@ void poll_initwait(struct poll_wqueues * { init_poll_funcptr(&pwq->pt, __pollwait); pwq->polling_task = current; + pwq->triggered = 0; pwq->error = 0; pwq->table = NULL; pwq->inline_index = 0;
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