Changeset 33537 in vbox for trunk/src/VBox

Timestamp:

Oct 28, 2010 8:49:11 AM (14 years ago)

Author:

vboxsync

svn:sync-xref-src-repo-rev:

67137

Message:

Apply timeout to 2 MB page allocation

File:

• trunk/src/VBox/VMM/PGMPhys.cpp (modified) (2 diffs)

trunk/src/VBox/VMM/PGMPhys.cpp

@@ -3846 +3846 @@
 {
 #ifdef PGM_WITH_LARGE_PAGES
-    uint64_t cbAvailableMem;
-
-    if (    RTSystemQueryAvailableRam(&cbAvailableMem) == VINF_SUCCESS
-        &&  cbAvailableMem < (UINT64_C(2) * _1G))
-    {
-        /** Too little free RAM left; don't bother as the host might try to move memory around, which is very expensive. */
-        LogRel(("PGMR3PhysAllocateLargeHandyPage: refuse to allocate large page; available memory on the host: %RX64\n", cbAvailableMem));
-        return VINF_EM_NO_MEMORY;
-    }
+    uint64_t u64TimeStamp1, u64TimeStamp2;
 
     pgmLock(pVM);
 
     STAM_PROFILE_START(&pVM->pgm.s.CTX_SUFF(pStats)->StatAllocLargePage, a);
+    u64TimeStamp1 = RTTimeMilliTS();
     int rc = VMMR3CallR0(pVM, VMMR0_DO_PGM_ALLOCATE_LARGE_HANDY_PAGE, 0, NULL);
+    u64TimeStamp2 = RTTimeMilliTS();
     STAM_PROFILE_STOP(&pVM->pgm.s.CTX_SUFF(pStats)->StatAllocLargePage, a);
     if (RT_SUCCESS(rc))
@@ -3926 +3920 @@
         }
         pVM->pgm.s.cLargeHandyPages = 0;
+    }
+
+    if (RT_SUCCESS(rc))
+    {
+        static uint32_t cTimeOut = 0;
+
+        if (u64TimeStamp2 - u64TimeStamp1 > 100)
+        {
+            if (++cTimeOut > 5)
+            {
+                /* If repeated attempts to allocate a large page takes more than 100 ms, then we fall back to normal 4k pages.
+                 * E.g. Vista 64 tries to move memory around, which takes a huge amount of time.
+                 */
+                LogRel(("PGMR3PhysAllocateLargePage: allocating large pages takes too long (last attempt %d ms); DISABLE\n", u64TimeStamp2 - u64TimeStamp1));
+                PGMSetLargePageUsage(pVM, false);
+            }
+        }
+        else
+        if (cTimeOut > 0)
+            cTimeOut--;
     }