Changeset 36962 in vbox for trunk/src/VBox/Runtime/r0drv/linux

Timestamp:

May 4, 2011 5:43:50 PM (14 years ago)

Author:

vboxsync

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

71558

Message:

rtR0MemAllocEx/linux: Avoid vmalloc, it's has serious performance issues. (I forget why we're switching between vmalloc and kmalloc here.)

File:

• trunk/src/VBox/Runtime/r0drv/linux/alloc-r0drv-linux.c (modified) (1 diff)

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

@@ -240 +240 @@
     else
     {
-        if (cb <= PAGE_SIZE || (fFlags & RTMEMHDR_FLAG_ANY_CTX))
+        if (
+#if 1 /* vmalloc has serious performance issues, avoid it. */
+               cb <= PAGE_SIZE*16 - sizeof(*pHdr)
+#else
+               cb <= PAGE_SIZE
+#endif
+            || (fFlags & RTMEMHDR_FLAG_ANY_CTX)
+           )
         {
             fFlags |= RTMEMHDR_FLAG_KMALLOC;
             pHdr = kmalloc(cb + sizeof(*pHdr),
                            (fFlags & RTMEMHDR_FLAG_ANY_CTX_ALLOC) ? GFP_ATOMIC : GFP_KERNEL);
+            if (RT_UNLIKELY(   !pHdr
+                            && cb > PAGE_SIZE
+                            && !(fFlags & RTMEMHDR_FLAG_ANY_CTX) ))
+            {
+                fFlags &= ~RTMEMHDR_FLAG_KMALLOC;
+                pHdr = vmalloc(cb + sizeof(*pHdr));
+            }
         }
         else