Differential D25496 Diff 74150 emulators/virtualbox-ose/files/patch-src-VBox-Runtime-r0drv-freebsd-sleepqueue-r0drv-freebsd.h
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emulators/virtualbox-ose/files/patch-src-VBox-Runtime-r0drv-freebsd-sleepqueue-r0drv-freebsd.h
| Without this patch any waits for periods shorter than a single tick return | Without this patch any waits for periods shorter than a single tick return | ||||
| immediately leading to a lot of unnecessary spinning. For example, I observe that | immediately leading to a lot of unnecessary spinning. For example, I observe that | ||||
| my guest's idle loop does a lot of sleeps with periods slightly shorter than 1 ms | my guest's idle loop does a lot of sleeps with periods slightly shorter than 1 ms | ||||
| (1/hz), e.g. 900us. All that waiting turns into pure spinning and VirtualBox eats | (1/hz), e.g. 900us. All that waiting turns into pure spinning and VirtualBox eats | ||||
| 100% of a core. | 100% of a core. | ||||
| The patch improves the situation significantly. Also, it (approximately) follows | The patch improves the situation significantly. Also, it (approximately) follows | ||||
| what tvtohz does. | what tvtohz does. | ||||
| Submitted by: Andriy Gapon <avg@FreeBSD.org> | Submitted by: Andriy Gapon <avg@FreeBSD.org> | ||||
| --- src/VBox/Runtime/r0drv/freebsd/sleepqueue-r0drv-freebsd.h.orig 2012-12-19 19:27:29.000000000 +0100 | --- src/VBox/Runtime/r0drv/freebsd/sleepqueue-r0drv-freebsd.h.orig 2020-05-13 19:44:32 UTC | ||||
| +++ src/VBox/Runtime/r0drv/freebsd/sleepqueue-r0drv-freebsd.h 2012-12-20 12:07:48.941861966 +0100 | +++ src/VBox/Runtime/r0drv/freebsd/sleepqueue-r0drv-freebsd.h | ||||
| @@ -82,6 +82,8 @@ | @@ -82,6 +82,8 @@ DECLINLINE(uint32_t) rtR0SemBsdWaitUpdateTimeout(PRTR0 | ||||
| uint64_t cTicks = ASMMultU64ByU32DivByU32(uTimeout, hz, UINT32_C(1000000000)); | uint64_t cTicks = ASMMultU64ByU32DivByU32(uTimeout, hz, UINT32_C(1000000000)); | ||||
| if (cTicks >= INT_MAX) | if (cTicks >= INT_MAX) | ||||
| return RTSEMWAIT_FLAGS_INDEFINITE; | return RTSEMWAIT_FLAGS_INDEFINITE; | ||||
| + else if (cTicks == 0 && uTimeout > 0) | + else if (cTicks == 0 && uTimeout > 0) | ||||
| + pWait->iTimeout = 1; | + pWait->iTimeout = 1; | ||||
| else | else | ||||
| pWait->iTimeout = (int)cTicks; | pWait->iTimeout = (int)cTicks; | ||||
| #endif | #endif | ||||