From 3340d280d7294c9b1e1927ce1804b23bcca428a6 Mon Sep 17 00:00:00 2001 From: Christoph Lameter Date: Tue, 6 Nov 2007 11:33:50 -0800 Subject: [PATCH] cpu alloc: i386 support Setup a 256 kB area for the cpu areas below the FIXADDR area. The use of the cpu alloc area is pretty minimal on i386. An 8p system with no extras uses only ~8kb. So 256kb should be plenty. A configuration that supports up to 8 processors takes up 2MB of the scarce virtual address space. Signed-off-by: Christoph Lameter --- arch/x86/mm/init_32.c | 3 +++ include/asm-x86/pgtable_32.h | 7 +++++-- 2 files changed, 8 insertions(+), 2 deletions(-) Index: linux-2.6/arch/x86/mm/init_32.c =================================================================== --- linux-2.6.orig/arch/x86/mm/init_32.c 2007-11-15 12:19:14.736945829 -0800 +++ linux-2.6/arch/x86/mm/init_32.c 2007-11-15 20:33:12.048796392 -0800 @@ -674,6 +674,7 @@ void __init mem_init(void) #if 1 /* double-sanity-check paranoia */ printk("virtual kernel memory layout:\n" " fixmap : 0x%08lx - 0x%08lx (%4ld kB)\n" + " cpu area: 0x%08lx - 0x%08lx (%4ld kb)\n" #ifdef CONFIG_HIGHMEM " pkmap : 0x%08lx - 0x%08lx (%4ld kB)\n" #endif @@ -684,6 +685,8 @@ void __init mem_init(void) " .text : 0x%08lx - 0x%08lx (%4ld kB)\n", FIXADDR_START, FIXADDR_TOP, (FIXADDR_TOP - FIXADDR_START) >> 10, + CPU_AREA_BASE, FIXADDR_START, + (FIXADDR_START - CPU_AREA_BASE) >> 10, #ifdef CONFIG_HIGHMEM PKMAP_BASE, PKMAP_BASE+LAST_PKMAP*PAGE_SIZE, Index: linux-2.6/include/asm-x86/pgtable_32.h =================================================================== --- linux-2.6.orig/include/asm-x86/pgtable_32.h 2007-11-15 12:19:16.975988139 -0800 +++ linux-2.6/include/asm-x86/pgtable_32.h 2007-11-15 20:33:12.073046255 -0800 @@ -79,11 +79,14 @@ void paging_init(void); #define VMALLOC_START (((unsigned long) high_memory + \ 2*VMALLOC_OFFSET-1) & ~(VMALLOC_OFFSET-1)) #ifdef CONFIG_HIGHMEM -# define VMALLOC_END (PKMAP_BASE-2*PAGE_SIZE) +# define CPU_AREA_BASE (PKMAP_BASE - NR_CPUS * \ + (1 << (CONFIG_CPU_AREA_ORDER + PAGE_SHIFT))) #else -# define VMALLOC_END (FIXADDR_START-2*PAGE_SIZE) +# define CPU_AREA_BASE (FIXADDR_START - NR_CPUS * \ + (1 << (CONFIG_CPU_AREA_ORDER + PAGE_SHIFT))) #endif +#define VMALLOC_END (CPU_AREA_BASE - 2 * PAGE_SIZE) /* * _PAGE_PSE set in the page directory entry just means that * the page directory entry points directly to a 4MB-aligned block of