Changeset 23093 in vbox for trunk/src

Timestamp:

Sep 17, 2009 1:46:30 PM (15 years ago)

Author:

vboxsync

Message:

PGM_SYNC_NR_PAGES increased for VT-x/AMD-V

File:

• trunk/src/VBox/VMM/PGMInternal.h (modified) (1 diff)

trunk/src/VBox/VMM/PGMInternal.h

@@ -83 +83 @@
  * When PGMPOOL_WITH_GCPHYS_TRACKING is enabled using high values here
  * causes a lot of unnecessary extents and also is slower than taking more \#PFs.
- */
-#define PGM_SYNC_NR_PAGES               8
+ *
+ * Note that \#PFs are much more expensive in the VT-x/AMD-V case due to
+ * world switch overhead, so let's sync more.
+ */
+# ifdef IN_RING0
+/* Chose 32 based on the compile test in #4219; 64 shows worse stats. 
+ * 32 again shows better results than 16; slightly more overhead in the \#PF handler,
+ * but ~5% fewer faults.
+ */
+# define PGM_SYNC_NR_PAGES               32
+#else
+# define PGM_SYNC_NR_PAGES               8
+#endif
 
 /**