x86: prepare page allocator for high allocations on PAGEALLOC=y
authorIngo Molnar <mingo@elte.hu>
Wed, 17 Oct 2007 16:04:34 +0000 (18:04 +0200)
committerThomas Gleixner <tglx@inhelltoy.tec.linutronix.de>
Wed, 17 Oct 2007 18:15:38 +0000 (20:15 +0200)
To preserve the DMA pool in CONFIG_DEBUG_PAGEALLOC=y kernels, we'll
allocate pagetables from above the 16MB DMA limit, so we'll have to set
up boot pagetables to cover 16MB more RAM (worst-case).

Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
arch/x86/kernel/head_32.S

index 9150ca9..0fa8a97 100644 (file)
  */
 LOW_PAGES = 1<<(32-PAGE_SHIFT_asm)
 
+/*
+ * To preserve the DMA pool in PAGEALLOC kernels, we'll allocate
+ * pagetables from above the 16MB DMA limit, so we'll have to set
+ * up pagetables 16MB more (worst-case):
+ */
+#ifdef CONFIG_DEBUG_PAGEALLOC
+LOW_PAGES = LOW_PAGES + 0x1000000
+#endif
+
 #if PTRS_PER_PMD > 1
 PAGE_TABLE_SIZE = (LOW_PAGES / PTRS_PER_PMD) + PTRS_PER_PGD
 #else