TechPanelGM/kernel_xiaomi_sm8250
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

net/fs: change busy poll time accounting

Browse Source 
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>
This commit is contained in:
Eliezer Tamir
2013-07-09 13:09:21 +03:00
committed by David S. Miller
parent cbf55001b2
commit 76b1e9b981
2 changed files with 39 additions and 49 deletions
Download Patch File Download Diff File Expand all files Collapse all files

31
fs/select.c
View File

@@ -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