|
Lines 1-13
Link Here
|
| 1 |
Without this patch any waits for periods shorter than a single tick return |
1 |
Without the first part of this patch, any waits for periods shorter than a |
| 2 |
immediately leading to a lot of unnecessary spinning. For example, I observe that |
2 |
single tick return immediately leading to a lot of unnecessary spinning. For |
| 3 |
my guest's idle loop does a lot of sleeps with periods slightly shorter than 1 ms |
3 |
example, I observe that my guest's idle loop does a lot of sleeps with periods |
| 4 |
(1/hz), e.g. 900us. All that waiting turns into pure spinning and VirtualBox eats |
4 |
slightly shorter than 1 ms (1/hz), e.g. 900us. All that waiting turns into pure |
| 5 |
100% of a core. |
5 |
spinning and VirtualBox eats 100% of a core. |
| 6 |
The patch improves the situation significantly. Also, it (approximately) follows |
6 |
|
| 7 |
what tvtohz does. |
7 |
The clamping improves the situation significantly. Also, it (approximately) |
|
|
8 |
follows what tvtohz does. The rest of the patch just chases an upstream |
| 9 |
KPI change. |
| 8 |
|
10 |
|
| 9 |
Submitted by: Andriy Gapon <avg@FreeBSD.org> |
11 |
Submitted by: Andriy Gapon <avg@FreeBSD.org> |
| 10 |
--- src/VBox/Runtime/r0drv/freebsd/sleepqueue-r0drv-freebsd.h.orig 2020-05-13 19:44:32 UTC |
12 |
--- src/VBox/Runtime/r0drv/freebsd/sleepqueue-r0drv-freebsd.h.orig 2020-07-09 16:57:38 UTC |
| 11 |
+++ src/VBox/Runtime/r0drv/freebsd/sleepqueue-r0drv-freebsd.h |
13 |
+++ src/VBox/Runtime/r0drv/freebsd/sleepqueue-r0drv-freebsd.h |
| 12 |
@@ -82,6 +82,8 @@ DECLINLINE(uint32_t) rtR0SemBsdWaitUpdateTimeout(PRTR0 |
14 |
@@ -82,6 +82,8 @@ DECLINLINE(uint32_t) rtR0SemBsdWaitUpdateTimeout(PRTR0 |
| 13 |
uint64_t cTicks = ASMMultU64ByU32DivByU32(uTimeout, hz, UINT32_C(1000000000)); |
15 |
uint64_t cTicks = ASMMultU64ByU32DivByU32(uTimeout, hz, UINT32_C(1000000000)); |
|
Lines 18-20
Submitted by: Andriy Gapon <avg@FreeBSD.org>
Link Here
|
| 18 |
else |
20 |
else |
| 19 |
pWait->iTimeout = (int)cTicks; |
21 |
pWait->iTimeout = (int)cTicks; |
| 20 |
#endif |
22 |
#endif |
| 21 |
- |
23 |
@@ -298,10 +300,16 @@ DECLINLINE(void) rtR0SemBsdSignal(void *pvWaitChan) |
|
|
24 |
DECLINLINE(void) rtR0SemBsdSignal(void *pvWaitChan) |
| 25 |
{ |
| 26 |
sleepq_lock(pvWaitChan); |
| 27 |
+#if __FreeBSD_version < 1500022 |
| 28 |
int fWakeupSwapProc = sleepq_signal(pvWaitChan, SLEEPQ_CONDVAR, 0, 0); |
| 29 |
+#else |
| 30 |
+ sleepq_signal(pvWaitChan, SLEEPQ_CONDVAR, 0, 0); |
| 31 |
+#endif |
| 32 |
sleepq_release(pvWaitChan); |
| 33 |
+#if __FreeBSD_version < 1500022 |
| 34 |
if (fWakeupSwapProc) |
| 35 |
kick_proc0(); |
| 36 |
+#endif |
| 37 |
} |
| 38 |
|
| 39 |
/** |