Changeset 22508 in vbox

Timestamp:

Aug 27, 2009 11:38:33 AM (15 years ago)

Author:

vboxsync

Message:

use GFP_DMA32 first on 32-bit PAE systems (like on 64-bit hosts) when allocating memory below 4GB

Location:

trunk/src/VBox/Runtime/r0drv/linux

Files:

• alloc-r0drv-linux.c (modified) (1 diff)
• memobj-r0drv-linux.c (modified) (2 diffs)

trunk/src/VBox/Runtime/r0drv/linux/alloc-r0drv-linux.c

@@ -239 +239 @@
     cPages = cb >> PAGE_SHIFT;
     cOrder = CalcPowerOf2Order(cPages);
+#if (defined(RT_ARCH_AMD64) || defined(CONFIG_X86_PAE)) && defined(GFP_DMA32)
+    paPages = alloc_pages(GFP_DMA32, cOrder);
+    if (!paPages)
+#endif
 #ifdef RT_ARCH_AMD64
-    /** @todo check out if there is a correct way of getting memory below 4GB (physically).
-     * GFP_DMA32 is available since Linux 2.6.15 */
-    paPages = alloc_pages(GFP_DMA, cOrder);
+        paPages = alloc_pages(GFP_DMA, cOrder);
 #else
-    /** XXX Wrong: GFP_USER can return page frames above 4GB! */
-    paPages = alloc_pages(GFP_USER, cOrder);
+# if defined(CONFIG_X86_PAE)
+    /** GFP_USER can return page frames above 4GB on PAE systems => GFP_DMA? */
+# endif
+        paPages = alloc_pages(GFP_USER, cOrder);
 #endif
     if (paPages)

trunk/src/VBox/Runtime/r0drv/linux/memobj-r0drv-linux.c

@@ -524 +524 @@
     int rc;
 
-#ifdef RT_ARCH_AMD64
-# ifdef GFP_DMA32
+    /* Try to avoid GFP_DMA. GFM_DMA32 was introduced with Linux 2.6.15. */
+#if (defined(RT_ARCH_AMD64) || defined(CONFIG_X86_PAE)) && defined(GFP_DMA32)
     rc = rtR0MemObjLinuxAllocPages(&pMemLnx, RTR0MEMOBJTYPE_LOW, cb, GFP_DMA32, false /* non-contiguous */);
     if (RT_FAILURE(rc))
-# endif
+#endif
+#ifdef RT_ARCH_AMD64
         rc = rtR0MemObjLinuxAllocPages(&pMemLnx, RTR0MEMOBJTYPE_LOW, cb, GFP_DMA, false /* non-contiguous */);
 #else
-    /** XXX Wrong: GFP_USER can return page frames above 4GB! */
-    rc = rtR0MemObjLinuxAllocPages(&pMemLnx, RTR0MEMOBJTYPE_LOW, cb, GFP_USER, false /* non-contiguous */);
+# ifdef CONFIG_X86_PAE
+        /** XXX GFP_USER can return page frames above 4GB on PAE systems => GFP_DMA? */
+# endif
+        rc = rtR0MemObjLinuxAllocPages(&pMemLnx, RTR0MEMOBJTYPE_LOW, cb, GFP_USER, false /* non-contiguous */);
 #endif
     if (RT_SUCCESS(rc))
@@ -556 +559 @@
     int rc;
 
-#ifdef RT_ARCH_AMD64
-# ifdef GFP_DMA32
+#if (defined(RT_ARCH_AMD64) || defined(CONFIG_X86_PAE)) && defined(GFP_DMA32)
     rc = rtR0MemObjLinuxAllocPages(&pMemLnx, RTR0MEMOBJTYPE_CONT, cb, GFP_DMA32, true /* contiguous */);
     if (RT_FAILURE(rc))
-# endif
+#endif
+#ifdef RT_ARCH_AMD64
         rc = rtR0MemObjLinuxAllocPages(&pMemLnx, RTR0MEMOBJTYPE_CONT, cb, GFP_DMA, true /* contiguous */);
 #else
-    rc = rtR0MemObjLinuxAllocPages(&pMemLnx, RTR0MEMOBJTYPE_CONT, cb, GFP_USER, true /* contiguous */);
+# if defined(CONFIG_X86_PAE)
+        /** XXX GFP_USER can return page frames above 4GB on PAE systems => GFP_DMA? */
+# endif
+        rc = rtR0MemObjLinuxAllocPages(&pMemLnx, RTR0MEMOBJTYPE_CONT, cb, GFP_USER, true /* contiguous */);
 #endif
     if (RT_SUCCESS(rc))