diff options
Diffstat (limited to 'emulators/virtualbox-ose-legacy/files/patch-src-VBox-Runtime-r0drv-freebsd-sleepqueue-r0drv-freebsd.h')
| -rw-r--r-- | emulators/virtualbox-ose-legacy/files/patch-src-VBox-Runtime-r0drv-freebsd-sleepqueue-r0drv-freebsd.h | 20 |
1 files changed, 20 insertions, 0 deletions
diff --git a/emulators/virtualbox-ose-legacy/files/patch-src-VBox-Runtime-r0drv-freebsd-sleepqueue-r0drv-freebsd.h b/emulators/virtualbox-ose-legacy/files/patch-src-VBox-Runtime-r0drv-freebsd-sleepqueue-r0drv-freebsd.h new file mode 100644 index 000000000000..8c4376c342e7 --- /dev/null +++ b/emulators/virtualbox-ose-legacy/files/patch-src-VBox-Runtime-r0drv-freebsd-sleepqueue-r0drv-freebsd.h @@ -0,0 +1,20 @@ +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 +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 +100% of a core. +The patch improves the situation significantly. Also, it (approximately) follows +what tvtohz does. + +Submitted by: Andriy Gapon <avg@FreeBSD.org> +--- 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 +@@ -82,6 +82,8 @@ DECLINLINE(uint32_t) rtR0SemBsdWaitUpdateTimeout(PRTR0 + uint64_t cTicks = ASMMultU64ByU32DivByU32(uTimeout, hz, UINT32_C(1000000000)); + if (cTicks >= INT_MAX) + return RTSEMWAIT_FLAGS_INDEFINITE; ++ else if (cTicks == 0 && uTimeout > 0) ++ pWait->iTimeout = 1; + else + pWait->iTimeout = (int)cTicks; + #endif |