Changeset 53458 in vbox for trunk/src/VBox/HostDrivers/Support/SUPDrv.c

Timestamp:

Dec 5, 2014 12:56:32 PM (10 years ago)

Author:

vboxsync

Message:

SUPDrv: Must increase the host timer frequence before we determin the interval just like we do when starting it, otherwise we might end up with an uneven interval (in ticks) because the clock tick length changes.

File:

• trunk/src/VBox/HostDrivers/Support/SUPDrv.c (modified) (7 diffs)

trunk/src/VBox/HostDrivers/Support/SUPDrv.c

@@ -3965 +3965 @@
 
 /**
+ * Increase the timer freqency on hosts where this is possible (NT).
+ *
+ * The idea is that more interrupts is better for us... Also, it's better than
+ * we increase the timer frequence, because we might end up getting inaccuract
+ * callbacks if someone else does it.
+ *
+ * @param   pDevExt   Sets u32SystemTimerGranularityGrant if increased.
+ */
+static void supdrvGipRequestHigherTimerFrequencyFromSystem(PSUPDRVDEVEXT pDevExt)
+{
+    if (pDevExt->u32SystemTimerGranularityGrant == 0)
+    {
+        uint32_t u32SystemResolution;
+        if (   RT_SUCCESS_NP(RTTimerRequestSystemGranularity(  976563 /* 1024 HZ */, &u32SystemResolution))
+            || RT_SUCCESS_NP(RTTimerRequestSystemGranularity( 1000000 /* 1000 HZ */, &u32SystemResolution))
+            || RT_SUCCESS_NP(RTTimerRequestSystemGranularity( 1953125 /*  512 HZ */, &u32SystemResolution))
+            || RT_SUCCESS_NP(RTTimerRequestSystemGranularity( 2000000 /*  500 HZ */, &u32SystemResolution))
+           )
+        {
+            Assert(RTTimerGetSystemGranularity() <= u32SystemResolution);
+            pDevExt->u32SystemTimerGranularityGrant = u32SystemResolution;
+        }
+    }
+}
+
+
+/**
+ * Undoes supdrvGipRequestHigherTimerFrequencyFromSystem.
+ *
+ * @param   pDevExt     Clears u32SystemTimerGranularityGrant.
+ */
+static void supdrvGipReleaseHigherTimerFrequencyFromSystem(PSUPDRVDEVEXT pDevExt)
+{
+    if (pDevExt->u32SystemTimerGranularityGrant)
+    {
+        int rc2 = RTTimerReleaseSystemGranularity(pDevExt->u32SystemTimerGranularityGrant);
+        AssertRC(rc2);
+        pDevExt->u32SystemTimerGranularityGrant = 0;
+    }
+}
+
+
+/**
  * Maps the GIP into userspace and/or get the physical address of the GIP.
  *
@@ -4028 +4071 @@
                 PSUPGLOBALINFOPAGE pGipR0 = pDevExt->pGip;
                 uint64_t u64NanoTS;
-                uint32_t u32SystemResolution;
-                unsigned i;
 
                 LogFlow(("SUPR0GipMap: Resumes GIP updating\n"));
 
-                /*
-                 * Try bump up the system timer resolution.
-                 * The more interrupts the better...
-                 */
-                /** @todo On Windows, RTTimerRequestSystemGranularity() always succeeds, so
-                 *        whats the point of the remaining calls? */
-                if (   RT_SUCCESS_NP(RTTimerRequestSystemGranularity(  976563 /* 1024 HZ */, &u32SystemResolution))
-                    || RT_SUCCESS_NP(RTTimerRequestSystemGranularity( 1000000 /* 1000 HZ */, &u32SystemResolution))
-                    || RT_SUCCESS_NP(RTTimerRequestSystemGranularity( 1953125 /*  512 HZ */, &u32SystemResolution))
-                    || RT_SUCCESS_NP(RTTimerRequestSystemGranularity( 2000000 /*  500 HZ */, &u32SystemResolution))
-                   )
-                {
-                    Assert(RTTimerGetSystemGranularity() <= u32SystemResolution);
-                    pDevExt->u32SystemTimerGranularityGrant = u32SystemResolution;
-                }
+                supdrvGipRequestHigherTimerFrequencyFromSystem(pDevExt);
 
                 if (pGipR0->aCPUs[0].u32TransactionId != 2 /* not the first time */)
                 {
+                    unsigned i;
                     for (i = 0; i < pGipR0->cCpus; i++)
                         ASMAtomicUoWriteU32(&pGipR0->aCPUs[i].u32TransactionId,
@@ -4152 +4180 @@
             rc = RTTimerStop(pDevExt->pGipTimer); AssertRC(rc); rc = VINF_SUCCESS;
 #endif
-
-            if (pDevExt->u32SystemTimerGranularityGrant)
-            {
-                int rc2 = RTTimerReleaseSystemGranularity(pDevExt->u32SystemTimerGranularityGrant);
-                AssertRC(rc2);
-                pDevExt->u32SystemTimerGranularityGrant = 0;
-            }
+            supdrvGipReleaseHigherTimerFrequencyFromSystem(pDevExt);
         }
     }
@@ -6305 +6327 @@
      * Find a reasonable update interval and initialize the structure.
      */
+    supdrvGipRequestHigherTimerFrequencyFromSystem(pDevExt);
     /** @todo figure out why using a 100Ms interval upsets timekeeping in VMs.
      *        See @bugref{6710}. */
@@ -6390 +6413 @@
                              */
                             Log(("supdrvGipCreate: %u ns interval.\n", u32Interval));
+                            supdrvGipReleaseHigherTimerFrequencyFromSystem(pDevExt);
+
                             g_pSUPGlobalInfoPage = pGip;
                             if (pGip->u32Mode == SUPGIPMODE_INVARIANT_TSC)
@@ -6416 +6441 @@
         OSDBGPRINT(("supdrvGipCreate: supdrvTscDeltaInit failed. rc=%Rrc\n", rc));
 
-    supdrvGipDestroy(pDevExt);
+    supdrvGipDestroy(pDevExt); /* Releases timer frequency increase too. */
     return rc;
 }
@@ -6485 +6510 @@
      * if one actually succeeded and is still pending.
      */
-    if (pDevExt->u32SystemTimerGranularityGrant)
-    {
-        rc = RTTimerReleaseSystemGranularity(pDevExt->u32SystemTimerGranularityGrant); AssertRC(rc);
-        pDevExt->u32SystemTimerGranularityGrant = 0;
-    }
+    supdrvGipReleaseHigherTimerFrequencyFromSystem(pDevExt);
 }