Il 18/09/2012 22:37, Anthony Liguori ha scritto:
> Unfortunately, there's a lot of Windows code in qemu-timer.c and main-loop.c
> right now otherwise the refactoring would be trivial. I'll leave that for
> another day.
>
> Cc: Paolo Bonzini <pbonz...@redhat.com>
> Cc: Jan Kiszka <jan.kis...@siemens.com>
> Signed-off-by: Anthony Liguori <aligu...@us.ibm.com>
> ---
> Please note, this is lightly tested. Since this is such a fundamental change,
> I'd like to do some performance analysis before committing but wanted to share
> early.
Looks good. I think Peter Portante tested something similar, and found no big
difference between the two. But it's a good thing and, in my opinion, for
non-timerfd OSes we should simply adjust the select() timeout and not bother
with signals.
I'm not sure if the same can be done for Windows, but I think it's possible as
long
as you keep the timeBeginPeriod/timeEndPeriod calls. As a start, Stefan, can
you
check if the win32 timer works for you with the calls added? Like this:
diff --git a/qemu-timer.c b/qemu-timer.c
index c7a1551..721c769 100644
--- a/qemu-timer.c
+++ b/qemu-timer.c
@@ -673,6 +673,10 @@ static int win32_start_timer(struct qemu_alarm_timer *t)
HANDLE hTimer;
BOOLEAN success;
+ timeGetDevCaps(&mm_tc, sizeof(mm_tc));
+
+ timeBeginPeriod(mm_tc.wPeriodMin);
+
/* If you call ChangeTimerQueueTimer on a one-shot timer (its period
is zero) that has already expired, the timer is not updated. Since
creating a new timer is relatively expensive, set a bogus one-hour
@@ -688,6 +692,7 @@ static int win32_start_timer(struct qemu_alarm_timer *t)
if (!success) {
fprintf(stderr, "Failed to initialize win32 alarm timer: %ld\n",
GetLastError());
+ timeEndPeriod(mm_tc.wPeriodMin);
return -1;
}
@@ -702,6 +707,7 @@ static void win32_stop_timer(struct qemu_alarm_timer *t)
if (hTimer) {
DeleteTimerQueueTimer(NULL, hTimer, NULL);
}
+ timeEndPeriod(mm_tc.wPeriodMin);
}
static void win32_rearm_timer(struct qemu_alarm_timer *t,
Paolo
