From 1e3e19723ecd58149388f3eecbd3285825f64f3b Mon Sep 17 00:00:00 2001 From: Ingo Molnar Date: Wed, 17 Oct 2007 18:04:34 +0200 Subject: [PATCH] x86: prepare page allocator for high allocations on PAGEALLOC=y 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 Signed-off-by: Thomas Gleixner --- arch/x86/kernel/head_32.S | 9 +++++++++ 1 file changed, 9 insertions(+) diff --git a/arch/x86/kernel/head_32.S b/arch/x86/kernel/head_32.S index 9150ca9b5f80..0fa8a972a679 100644 --- a/arch/x86/kernel/head_32.S +++ b/arch/x86/kernel/head_32.S @@ -51,6 +51,15 @@ */ 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 -- 2.20.1