Changeset 90558 in vbox for trunk/src/VBox/VMM/VMMAll

Timestamp:

Aug 6, 2021 8:36:24 PM (3 years ago)

Author:

vboxsync

Message:

VMM/PGMCritSect: Avoid queuing on PDMCritSectLeave contention and include more contexts where we trust calling SUPSemEventSignal (targetting solaris). bugref:6695

File:

• trunk/src/VBox/VMM/VMMAll/PDMAllCritSect.cpp (modified) (1 diff)

trunk/src/VBox/VMM/VMMAll/PDMAllCritSect.cpp

@@ -897 +897 @@
     pCritSect->s.hEventToSignal = NIL_SUPSEMEVENT;
     PVMCPUCC pVCpu           = VMMGetCpu(pVM);
-    bool     fQueueOnTrouble = true;
+    bool     fQueueOnTrouble = false; /* Set this to true to test queueing. */
     if (   pVCpu == NULL /* non-EMT access, if we implement it must be able to block */
         || VMMRZCallRing3IsEnabled(pVCpu)
         || RTSemEventIsSignalSafe()
+        || (   VMMR0ThreadCtxHookIsEnabled(pVCpu)       /* Doesn't matter if Signal() blocks if we have hooks, ... */
+            && RTThreadPreemptIsEnabled(NIL_RTTHREAD)   /* ... and preemption is still enabled, */
+            && ASMIntAreEnabled())                      /* ... and interrupts hasn't yet been disabled. Special pre-GC HM env. */
         || (fQueueOnTrouble = (   hEventToSignal == NIL_SUPSEMEVENT
                                && ASMAtomicUoReadS32(&pCritSect->s.Core.cLockers) == 0)) )