diff options
| author | Eliezer Tamir <eliezer.tamir@linux.intel.com> | 2013-07-09 13:09:21 +0300 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2013-07-09 12:33:04 -0700 |
| commit | 76b1e9b9813e412bde7446525f6c299803713545 (patch) | |
| tree | f062c481d287f1c3b186a9ede8d61abffcf06f8f /fs/select.c | |
| parent | cbf55001b2ddb814329735641be5d29b08c82b08 (diff) | |
| download | lwn-76b1e9b9813e412bde7446525f6c299803713545.tar.gz lwn-76b1e9b9813e412bde7446525f6c299803713545.zip | |
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.c | 31 |
1 files changed, 20 insertions, 11 deletions
diff --git a/fs/select.c b/fs/select.c index 25cac5faf6d6..50a804b6839f 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 |