annotate poll(2) guts (fb367937) · Commits · 戴 / test

fs/select.c

+10 −6

Original line number	Diff line number	Diff line
		@@ -803,9 +803,9 @@ struct poll_list {
		* pwait poll_table will be used by the fd-provided poll handler for waiting,
		* if pwait->_qproc is non-NULL.
		*/
		static inline unsigned int do_pollfd(struct pollfd pollfd, poll_table pwait,
		static inline __poll_t do_pollfd(struct pollfd pollfd, poll_table pwait,
		bool *can_busy_poll,
		unsigned int busy_flag)
		__poll_t busy_flag)
		{
		__poll_t mask;
		int fd;
		@@ -816,20 +816,24 @@ static inline unsigned int do_pollfd(struct pollfd pollfd, poll_table pwait,
		struct fd f = fdget(fd);
		mask = POLLNVAL;
		if (f.file) {
		/* userland u16 ->events contains POLL... bitmap */
		__poll_t filter = (__force __poll_t)pollfd->events \|
		POLLERR \| POLLHUP;
		mask = DEFAULT_POLLMASK;
		if (f.file->f_op->poll) {
		pwait->_key = pollfd->events\|POLLERR\|POLLHUP;
		pwait->_key = filter;
		pwait->_key \|= busy_flag;
		mask = f.file->f_op->poll(f.file, pwait);
		if (mask & busy_flag)
		*can_busy_poll = true;
		}
		/* Mask out unneeded events. */
		mask &= pollfd->events \| POLLERR \| POLLHUP;
		mask &= filter;
		fdput(f);
		}
		}
		pollfd->revents = mask;
		/* ... and so does ->revents */
		pollfd->revents = (__force u16)mask;

		return mask;
		}
		@@ -841,7 +845,7 @@ static int do_poll(struct poll_list list, struct poll_wqueues wait,
		ktime_t expire, *to = NULL;
		int timed_out = 0, count = 0;
		u64 slack = 0;
		unsigned int busy_flag = net_busy_loop_on() ? POLL_BUSY_LOOP : 0;
		__poll_t busy_flag = net_busy_loop_on() ? POLL_BUSY_LOOP : 0;
		unsigned long busy_start = 0;

		/* Optimise the no-wait case */