diff options
Diffstat (limited to 'fs')
| -rw-r--r-- | fs/select.c | 60 |
1 files changed, 37 insertions, 23 deletions
diff --git a/fs/select.c b/fs/select.c index f28a58592725..25cac5faf6d6 100644 --- a/fs/select.c +++ b/fs/select.c @@ -402,9 +402,9 @@ 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 = ll_get_flag(); - u64 ll_start = ll_start_time(ll_flag); - u64 ll_time = ll_run_time(); + unsigned int busy_flag = net_busy_loop_on() ? POLL_BUSY_LOOP : 0; + u64 busy_start = busy_loop_start_time(busy_flag); + u64 busy_end = busy_loop_end_time(); rcu_read_lock(); retval = max_select_fd(n, fds); @@ -427,7 +427,7 @@ 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; + bool can_busy_loop = false; inp = fds->in; outp = fds->out; exp = fds->ex; rinp = fds->res_in; routp = fds->res_out; rexp = fds->res_ex; @@ -456,7 +456,7 @@ int do_select(int n, fd_set_bits *fds, struct timespec *end_time) mask = DEFAULT_POLLMASK; if (f_op && f_op->poll) { wait_key_set(wait, in, out, - bit, ll_flag); + bit, busy_flag); mask = (*f_op->poll)(f.file, wait); } fdput(f); @@ -475,11 +475,18 @@ 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 (retval) { + can_busy_loop = false; + busy_flag = 0; + + /* + * only remember a returned + * POLL_BUSY_LOOP if we asked for it + */ + } else if (busy_flag & mask) + can_busy_loop = true; + } } if (res_in) @@ -498,8 +505,9 @@ int do_select(int n, fd_set_bits *fds, struct timespec *end_time) break; } - /* only if on, have sockets with POLL_LL and not out of time */ - if (ll_flag && can_ll && can_poll_ll(ll_start, ll_time)) + /* only if found POLL_BUSY_LOOP sockets && not out of time */ + if (!need_resched() && can_busy_loop && + busy_loop_range(busy_start, busy_end)) continue; /* @@ -734,7 +742,8 @@ struct poll_list { * if pwait->_qproc is non-NULL. */ static inline unsigned int do_pollfd(struct pollfd *pollfd, poll_table *pwait, - bool *can_ll, unsigned int ll_flag) + bool *can_busy_poll, + unsigned int busy_flag) { unsigned int mask; int fd; @@ -748,10 +757,10 @@ 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; + pwait->_key |= busy_flag; mask = f.file->f_op->poll(f.file, pwait); - if (mask & POLL_LL) - *can_ll = true; + if (mask & busy_flag) + *can_busy_poll = true; } /* Mask out unneeded events. */ mask &= pollfd->events | POLLERR | POLLHUP; @@ -770,9 +779,10 @@ 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 = ll_get_flag(); - u64 ll_start = ll_start_time(ll_flag); - u64 ll_time = ll_run_time(); + unsigned int busy_flag = net_busy_loop_on() ? POLL_BUSY_LOOP : 0; + u64 busy_start = busy_loop_start_time(busy_flag); + u64 busy_end = busy_loop_end_time(); + /* Optimise the no-wait case */ if (end_time && !end_time->tv_sec && !end_time->tv_nsec) { @@ -785,7 +795,7 @@ static int do_poll(unsigned int nfds, struct poll_list *list, for (;;) { struct poll_list *walk; - bool can_ll = false; + bool can_busy_loop = false; for (walk = list; walk != NULL; walk = walk->next) { struct pollfd * pfd, * pfd_end; @@ -800,10 +810,13 @@ 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, &can_ll, ll_flag)) { + if (do_pollfd(pfd, pt, &can_busy_loop, + busy_flag)) { count++; pt->_qproc = NULL; - ll_flag = 0; + /* found something, stop busy polling */ + busy_flag = 0; + can_busy_loop = false; } } } @@ -820,8 +833,9 @@ static int do_poll(unsigned int nfds, struct poll_list *list, if (count || timed_out) break; - /* only if on, have sockets with POLL_LL and not out of time */ - if (ll_flag && can_ll && can_poll_ll(ll_start, ll_time)) + /* only if found POLL_BUSY_LOOP sockets && not out of time */ + if (!need_resched() && can_busy_loop && + busy_loop_range(busy_start, busy_end)) continue; /* |