diff options
Diffstat (limited to 'fs/select.c')
| -rw-r--r-- | fs/select.c | 34 |
1 files changed, 29 insertions, 5 deletions
diff --git a/fs/select.c b/fs/select.c index 8c1c96c27062..79b876eb91da 100644 --- a/fs/select.c +++ b/fs/select.c @@ -27,6 +27,7 @@ #include <linux/rcupdate.h> #include <linux/hrtimer.h> #include <linux/sched/rt.h> +#include <net/ll_poll.h> #include <asm/uaccess.h> @@ -384,9 +385,10 @@ get_max: #define POLLEX_SET (POLLPRI) static inline void wait_key_set(poll_table *wait, unsigned long in, - unsigned long out, unsigned long bit) + unsigned long out, unsigned long bit, + unsigned int ll_flag) { - wait->_key = POLLEX_SET; + wait->_key = POLLEX_SET | ll_flag; if (in & bit) wait->_key |= POLLIN_SET; if (out & bit) @@ -400,6 +402,8 @@ int do_select(int n, fd_set_bits *fds, struct timespec *end_time) poll_table *wait; int retval, i, timed_out = 0; unsigned long slack = 0; + unsigned int ll_flag = POLL_LL; + u64 ll_time = ll_end_time(); rcu_read_lock(); retval = max_select_fd(n, fds); @@ -422,6 +426,7 @@ int do_select(int n, fd_set_bits *fds, struct timespec *end_time) retval = 0; for (;;) { unsigned long *rinp, *routp, *rexp, *inp, *outp, *exp; + bool can_ll = false; inp = fds->in; outp = fds->out; exp = fds->ex; rinp = fds->res_in; routp = fds->res_out; rexp = fds->res_ex; @@ -449,7 +454,8 @@ int do_select(int n, fd_set_bits *fds, struct timespec *end_time) f_op = f.file->f_op; mask = DEFAULT_POLLMASK; if (f_op && f_op->poll) { - wait_key_set(wait, in, out, bit); + wait_key_set(wait, in, out, + bit, ll_flag); mask = (*f_op->poll)(f.file, wait); } fdput(f); @@ -468,6 +474,11 @@ int do_select(int n, fd_set_bits *fds, struct timespec *end_time) retval++; wait->_qproc = NULL; } + if (mask & POLL_LL) + can_ll = true; + /* got something, stop busy polling */ + if (retval) + ll_flag = 0; } } if (res_in) @@ -486,6 +497,9 @@ int do_select(int n, fd_set_bits *fds, struct timespec *end_time) break; } + if (can_ll && can_poll_ll(ll_time)) + continue; + /* * If this is the first loop and we have a timeout * given, then we convert to ktime_t and set the to @@ -717,7 +731,8 @@ 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 unsigned int do_pollfd(struct pollfd *pollfd, poll_table *pwait, + bool *can_ll, unsigned int ll_flag) { unsigned int mask; int fd; @@ -731,7 +746,10 @@ static inline unsigned int do_pollfd(struct pollfd *pollfd, poll_table *pwait) mask = DEFAULT_POLLMASK; if (f.file->f_op && f.file->f_op->poll) { pwait->_key = pollfd->events|POLLERR|POLLHUP; + pwait->_key |= ll_flag; mask = f.file->f_op->poll(f.file, pwait); + if (mask & POLL_LL) + *can_ll = true; } /* Mask out unneeded events. */ mask &= pollfd->events | POLLERR | POLLHUP; @@ -750,6 +768,8 @@ static int do_poll(unsigned int nfds, struct poll_list *list, ktime_t expire, *to = NULL; int timed_out = 0, count = 0; unsigned long slack = 0; + unsigned int ll_flag = POLL_LL; + u64 ll_time = ll_end_time(); /* Optimise the no-wait case */ if (end_time && !end_time->tv_sec && !end_time->tv_nsec) { @@ -762,6 +782,7 @@ static int do_poll(unsigned int nfds, struct poll_list *list, for (;;) { struct poll_list *walk; + bool can_ll = false; for (walk = list; walk != NULL; walk = walk->next) { struct pollfd * pfd, * pfd_end; @@ -776,9 +797,10 @@ static int do_poll(unsigned int nfds, struct poll_list *list, * this. They'll get immediately deregistered * when we break out and return. */ - if (do_pollfd(pfd, pt)) { + if (do_pollfd(pfd, pt, &can_ll, ll_flag)) { count++; pt->_qproc = NULL; + ll_flag = 0; } } } @@ -795,6 +817,8 @@ static int do_poll(unsigned int nfds, struct poll_list *list, if (count || timed_out) break; + if (can_ll && can_poll_ll(ll_time)) + continue; /* * If this is the first loop and we have a timeout * given, then we convert to ktime_t and set the to |