Changeset 88088 in vbox

Timestamp:

Mar 11, 2021 1:05:43 PM (4 years ago)

Author:

vboxsync

Message:

VMM/TM: Try make sure the load doesn't exceed 100% after the switch from RTTimeNanoTS to RDTSC for the execute part. bugref:9941

File:

• trunk/src/VBox/VMM/VMMR3/TM.cpp (modified) (1 diff)

trunk/src/VBox/VMM/VMMR3/TM.cpp

@@ -3566 +3566 @@
     /* Calc & update deltas */
     uint64_t cNsTotalDelta      = cNsTotal     - pState->cNsPrevTotal;
+    uint64_t cNsExecutingDelta  = cNsExecuting - pState->cNsPrevExecuting;
+    uint64_t cNsHaltedDelta     = cNsHalted    - pState->cNsPrevHalted;
+
+    if (cNsExecutingDelta + cNsHaltedDelta <= cNsTotalDelta)
+    { /* likely */ }
+    else
+    {
+        /* Just adjust the executing and halted values down to match the total delta. */
+        uint64_t const cNsExecAndHalted = cNsExecutingDelta + cNsHaltedDelta;
+        uint64_t const cNsAdjust        = cNsExecAndHalted - cNsTotalDelta + cNsTotalDelta / 64;
+        cNsExecutingDelta -= (cNsAdjust * cNsExecutingDelta + cNsExecAndHalted - 1) / cNsExecAndHalted;
+        cNsHaltedDelta    -= (cNsAdjust * cNsHaltedDelta    + cNsExecAndHalted - 1) / cNsExecAndHalted;
+        Assert(cNsExecutingDelta + cNsHaltedDelta <= cNsTotalDelta);
+    }
+
+    pState->cNsPrevExecuting    = cNsExecuting;
+    pState->cNsPrevHalted       = cNsHalted;
     pState->cNsPrevTotal        = cNsTotal;
-
-    uint64_t cNsExecutingDelta  = cNsExecuting - pState->cNsPrevExecuting;
-    pState->cNsPrevExecuting    = cNsExecuting;
-
-    uint64_t cNsHaltedDelta     = cNsHalted    - pState->cNsPrevHalted;
-    pState->cNsPrevHalted       = cNsHalted;
 
     /* Calc pcts. */