Commit 357c692cca6614ac3583ca39b710a9888a673785

Authored by aliguori
1 parent 9c99d2ab

Revert r5636 to fix icount on hosts w/o high-res clocks

Changeset r5636 changed the timers to run in the alarm callback.  The 
alarm callback can only be called as frequently as the host alarm timer 
fires.  For older Linux hosts and possibly non-Linux hosts, this can be 
as high as a 1ms granularity.

icount calculates the select timeout based on the next deadline and 
select is usually capable of sleeping for a short period of time than 
alarm timer granularity.  This means that changing the timer callbacks 
to be based on alarm firing caused timers to fire much later than they 
ought to when using icount.

Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>



git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@5796 c046a42c-6fe2-441c-8c8c-71466251a162
Showing 1 changed file with 9 additions and 9 deletions
... ... @@ -1624,15 +1624,6 @@ static void try_to_rearm_timer(void *opaque)
1624 1624 } while ((len == -1 && errno == EINTR) || len > 0);
1625 1625 #endif
1626 1626  
1627   - /* vm time timers */
1628   - if (vm_running && likely(!(cur_cpu->singlestep_enabled & SSTEP_NOTIMER)))
1629   - qemu_run_timers(&active_timers[QEMU_TIMER_VIRTUAL],
1630   - qemu_get_clock(vm_clock));
1631   -
1632   - /* real time timers */
1633   - qemu_run_timers(&active_timers[QEMU_TIMER_REALTIME],
1634   - qemu_get_clock(rt_clock));
1635   -
1636 1627 if (t->flags & ALARM_FLAG_EXPIRED) {
1637 1628 alarm_timer->flags &= ~ALARM_FLAG_EXPIRED;
1638 1629 qemu_rearm_alarm_timer(alarm_timer);
... ... @@ -3629,6 +3620,15 @@ void main_loop_wait(int timeout)
3629 3620 }
3630 3621 #endif
3631 3622  
  3623 + /* vm time timers */
  3624 + if (vm_running && likely(!(cur_cpu->singlestep_enabled & SSTEP_NOTIMER)))
  3625 + qemu_run_timers(&active_timers[QEMU_TIMER_VIRTUAL],
  3626 + qemu_get_clock(vm_clock));
  3627 +
  3628 + /* real time timers */
  3629 + qemu_run_timers(&active_timers[QEMU_TIMER_REALTIME],
  3630 + qemu_get_clock(rt_clock));
  3631 +
3632 3632 /* Check bottom-halves last in case any of the earlier events triggered
3633 3633 them. */
3634 3634 qemu_bh_poll();
... ...