Place all low mem in DMA pool.

Signed-off-by: Keir Fraser <keir@xensource.com>

diff --git a/linux-2.6-xen-sparse/arch/xen/i386/kernel/setup.c b/linux-2.6-xen-sparse/arch/xen/i386/kernel/setup.c
index bc86051db3fcd534e2b2c68782ee5d4784fcfa7c..20d9fc467a993bd87b80b1c3b9b526d751c78a77 100644 (file)
--- a/linux-2.6-xen-sparse/arch/xen/i386/kernel/setup.c
+++ b/linux-2.6-xen-sparse/arch/xen/i386/kernel/setup.c
@@ -1107,7 +1107,14 @@ void __init zone_sizes_init(void)
        unsigned long zones_size[MAX_NR_ZONES] = {0, 0, 0};
        unsigned int max_dma, low;
 
-       max_dma = virt_to_phys((char *)MAX_DMA_ADDRESS) >> PAGE_SHIFT;
+       /*
+        * XEN: Our notion of "DMA memory" is fake when running over Xen.
+        * We simply put all RAM in the DMA zone so that those drivers which
+        * needlessly specify GFP_DMA do not get starved of RAM unnecessarily.
+        * Those drivers that *do* require lowmem are screwed anyway when
+        * running over Xen!
+        */
+       max_dma = max_low_pfn;
        low = max_low_pfn;
 
        if (low < max_dma)