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authorEliezer Tamir <eliezer.tamir@linux.intel.com>2013-07-09 13:09:21 +0300
committerDavid S. Miller <davem@davemloft.net>2013-07-09 12:33:04 -0700
commit76b1e9b9813e412bde7446525f6c299803713545 (patch)
treef062c481d287f1c3b186a9ede8d61abffcf06f8f /fs/select.c
parentcbf55001b2ddb814329735641be5d29b08c82b08 (diff)
net/fs: change busy poll time accounting
Suggested by Linus: Changed time accounting for busy-poll: - Make it microsecond based. - Use unsigned longs. - Revert back to use time_after instead of time_in_range. Reorder poll/select busy loop conditions: - Clear busy_flag after one time we can't busy-poll. - Only init busy_end if we actually are going to busy-poll. Added one more missing need_resched() test. Signed-off-by: Eliezer Tamir <eliezer.tamir@linux.intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'fs/select.c')
-rw-r--r--fs/select.c31
1 files changed, 20 insertions, 11 deletions
diff --git a/fs/select.c b/fs/select.c
index 25cac5faf6d..50a804b6839 100644
--- a/fs/select.c
+++ b/fs/select.c
@@ -403,8 +403,7 @@ int do_select(int n, fd_set_bits *fds, struct timespec *end_time)
int retval, i, timed_out = 0;
unsigned long slack = 0;
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();
+ unsigned long busy_end = 0;
rcu_read_lock();
retval = max_select_fd(n, fds);
@@ -506,9 +505,15 @@ int do_select(int n, fd_set_bits *fds, struct timespec *end_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;
+ 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
@@ -780,9 +785,7 @@ static int do_poll(unsigned int nfds, struct poll_list *list,
int timed_out = 0, count = 0;
unsigned long slack = 0;
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();
-
+ unsigned long busy_end = 0;
/* Optimise the no-wait case */
if (end_time && !end_time->tv_sec && !end_time->tv_nsec) {
@@ -834,9 +837,15 @@ static int do_poll(unsigned int nfds, struct poll_list *list,
break;
/* 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;
+ 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