#include <linux/hrtimer.h>
#include <linux/sched/rt.h>
#include <linux/freezer.h>
+#include <net/busy_poll.h>
#include <asm/uaccess.h>
return slack;
}
-long select_estimate_accuracy(struct timespec *tv)
+u64 select_estimate_accuracy(struct timespec *tv)
{
- unsigned long ret;
+ u64 ret;
struct timespec now;
/*
* doesn't imply write barrier and the users expect write
* barrier semantics on wakeup functions. The following
* smp_wmb() is equivalent to smp_wmb() in try_to_wake_up()
- * and is paired with set_mb() in poll_schedule_timeout.
+ * and is paired with smp_store_mb() in poll_schedule_timeout.
*/
smp_wmb();
pwq->triggered = 1;
set_current_state(state);
if (!pwq->triggered)
- rc = freezable_schedule_hrtimeout_range(expires, slack,
- HRTIMER_MODE_ABS);
+ rc = schedule_hrtimeout_range(expires, slack, HRTIMER_MODE_ABS);
__set_current_state(TASK_RUNNING);
/*
* Prepare for the next iteration.
*
- * The following set_mb() serves two purposes. First, it's
+ * The following smp_store_mb() serves two purposes. First, it's
* the counterpart rmb of the wmb in pollwake() such that data
* written before wake up is always visible after wake up.
* Second, the full barrier guarantees that triggered clearing
* this problem doesn't exist for the first iteration as
* add_wait_queue() has full barrier semantics.
*/
- set_mb(pwq->triggered, 0);
+ smp_store_mb(pwq->triggered, 0);
return rc;
}
#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)
struct poll_wqueues table;
poll_table *wait;
int retval, i, timed_out = 0;
- unsigned long slack = 0;
+ u64 slack = 0;
+ unsigned int busy_flag = net_busy_loop_on() ? POLL_BUSY_LOOP : 0;
+ unsigned long busy_end = 0;
rcu_read_lock();
retval = max_select_fd(n, fds);
retval = 0;
for (;;) {
unsigned long *rinp, *routp, *rexp, *inp, *outp, *exp;
+ 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;
const struct file_operations *f_op;
f_op = f.file->f_op;
mask = DEFAULT_POLLMASK;
- if (f_op && f_op->poll) {
- wait_key_set(wait, in, out, bit);
+ if (f_op->poll) {
+ wait_key_set(wait, in, out,
+ bit, busy_flag);
mask = (*f_op->poll)(f.file, wait);
}
fdput(f);
retval++;
wait->_qproc = NULL;
}
+ /* got something, stop busy polling */
+ 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)
break;
}
+ /* only if found POLL_BUSY_LOOP sockets && not out of time */
+ if (can_busy_loop && !need_resched()) {
+ if (!busy_end) {
+ busy_end = busy_loop_end_time();
+ continue;
+ }
+ if (!busy_loop_timeout(busy_end))
+ continue;
+ }
+ busy_flag = 0;
+
/*
* If this is the first loop and we have a timeout
* given, then we convert to ktime_t and set the to
* 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_busy_poll,
+ unsigned int busy_flag)
{
unsigned int mask;
int fd;
mask = POLLNVAL;
if (f.file) {
mask = DEFAULT_POLLMASK;
- if (f.file->f_op && f.file->f_op->poll) {
+ if (f.file->f_op->poll) {
pwait->_key = pollfd->events|POLLERR|POLLHUP;
+ 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;
poll_table* pt = &wait->pt;
ktime_t expire, *to = NULL;
int timed_out = 0, count = 0;
- unsigned long slack = 0;
+ u64 slack = 0;
+ unsigned int busy_flag = net_busy_loop_on() ? POLL_BUSY_LOOP : 0;
+ unsigned long busy_end = 0;
/* Optimise the no-wait case */
if (end_time && !end_time->tv_sec && !end_time->tv_nsec) {
for (;;) {
struct poll_list *walk;
+ bool can_busy_loop = false;
for (walk = list; walk != NULL; walk = walk->next) {
struct pollfd * pfd, * pfd_end;
* this. They'll get immediately deregistered
* when we break out and return.
*/
- if (do_pollfd(pfd, pt)) {
+ if (do_pollfd(pfd, pt, &can_busy_loop,
+ busy_flag)) {
count++;
pt->_qproc = NULL;
+ /* found something, stop busy polling */
+ busy_flag = 0;
+ can_busy_loop = false;
}
}
}
if (count || timed_out)
break;
+ /* only if found POLL_BUSY_LOOP sockets && not out of time */
+ if (can_busy_loop && !need_resched()) {
+ if (!busy_end) {
+ busy_end = busy_loop_end_time();
+ continue;
+ }
+ if (!busy_loop_timeout(busy_end))
+ continue;
+ }
+ busy_flag = 0;
+
/*
* If this is the first loop and we have a timeout
* given, then we convert to ktime_t and set the to
if (ret == -EINTR) {
struct restart_block *restart_block;
- restart_block = ¤t_thread_info()->restart_block;
+ restart_block = ¤t->restart_block;
restart_block->fn = do_restart_poll;
restart_block->poll.ufds = ufds;
restart_block->poll.nfds = nfds;
projects / firefly-linux-kernel-4.4.55.git / blobdiff