Messages in this thread Patch in this message | | | Date | Sat, 15 Aug 2009 19:30:24 +0200 | From | Guillaume Knispel <> | Subject | [PATCH] poll/select: initialize triggered field of struct poll_wqueues |
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Hi,
That's only the second time I read fs/select.c so this has to be reviewed carefully. It has been quickly tested on my Debian Lenny x86_32 box and everything seems to works fine on the surface.
Cheers, Guillaume Knispel
poll/select: initialize triggered field of struct poll_wqueues
The triggered field of struct poll_wqueues introduced in commit 5f820f648c92a5ecc771a96b3c29aa6e90013bba "poll: allow f_op->poll to sleep" was 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> --- fs/select.c | 1 + 1 files changed, 1 insertions(+), 0 deletions(-)
diff --git a/fs/select.c b/fs/select.c index d870237..8084834 100644 --- a/fs/select.c +++ b/fs/select.c @@ -110,6 +110,7 @@ void poll_initwait(struct poll_wqueues *pwq) { 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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