Changeset 53459 in vbox for trunk/src

Timestamp:

Dec 5, 2014 1:07:30 PM (10 years ago)

Author:

vboxsync

Message:

SUPDrv.c: Removed RTTimeSystemNanoTS() CPU burning loop from supdrvGipSyncTimer and marked the one in supdrvRefineTscTimer as a portability issue. Also added a todo about moving global data variables.

File:

• trunk/src/VBox/HostDrivers/Support/SUPDrv.c (modified) (5 diffs)

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

@@ -187 +187 @@
 DECLEXPORT(PSUPGLOBALINFOPAGE) g_pSUPGlobalInfoPage = NULL;
 
+/** @name r=bird: Stuff that should be SUPDRVDEVEXT members.
+ * @todo Move this ASAP.  */
 /**
  * The TSC delta synchronization struct. rounded to cache line size.
@@ -218 +220 @@
  *  CPUs. */
 static bool                 g_fOsTscDeltasInSync;
+/** @}  */
 
 /**
@@ -6061 +6064 @@
         /*
          * Synchronize with the host OS clock tick before reading the TSC.
-         * Especially important on Windows where the granularity is terrible.
+         * Especially important on older Windows version where the granularity is terrible.
          */
         u64NanoTsBefore = RTTimeSystemNanoTS();
@@ -6170 +6173 @@
     Assert(pGip->u32Mode == SUPGIPMODE_INVARIANT_TSC);
 
+#if !defined(RT_OS_OS2) /* PORTME: Disable if timers are called from clock interrupt handler or with interrupts disabled. */
     u64NanoTS = RTTimeSystemNanoTS();
     while (RTTimeSystemNanoTS() == u64NanoTS)
         ASMNopPause();
+#endif
     uFlags    = ASMIntDisableFlags();
     idApic    = ASMGetApicId();
@@ -6528 +6533 @@
     PSUPGLOBALINFOPAGE pGip = pDevExt->pGip;
 
-    /*
-     * Synchronize with the host OS clock tick before reading the TSC.
-     * Especially important on Windows where the granularity is terrible.
-     */
-    u64NanoTS = RTTimeSystemNanoTS();
-    while (u64NanoTS == RTTimeSystemNanoTS())
-        ASMNopPause();
-
     uFlags    = ASMIntDisableFlags(); /* No interruptions please (real problem on S10). */
     u64TSC    = ASMReadTSC();