From: Andy Whitcroft (Comment changes only) The bootmem allocator is initialised before the kernel virtual address space has been fully established. As a result, any allocations which are made before paging_init() has completed may point to invalid kernel addresses. This patch notes this limitation and indicates where the allocator is fully available. Signed-off-by: Andy Whitcroft Signed-off-by: Andrew Morton --- 25-akpm/arch/i386/kernel/setup.c | 11 ++++++++++- 1 files changed, 10 insertions(+), 1 deletion(-) diff -puN arch/i386/kernel/setup.c~i386-bootmem-restrictions arch/i386/kernel/setup.c --- 25/arch/i386/kernel/setup.c~i386-bootmem-restrictions 2004-08-30 00:51:38.353812352 -0700 +++ 25-akpm/arch/i386/kernel/setup.c 2004-08-30 00:51:38.357811744 -0700 @@ -1355,7 +1355,12 @@ void __init setup_arch(char **cmdline_p) /* * NOTE: before this point _nobody_ is allowed to allocate - * any memory using the bootmem allocator. + * any memory using the bootmem allocator. Although the + * alloctor is now initialised only the first 8Mb of the kernel + * virtual address space has been mapped. All allocations before + * paging_init() has completed must use the alloc_bootmem_low_pages() + * variant (which allocates DMA'able memory) and care must be taken + * not to exceed the 8Mb limit. */ #ifdef CONFIG_SMP @@ -1363,6 +1368,10 @@ void __init setup_arch(char **cmdline_p) #endif paging_init(); + /* + * NOTE: at this point the bootmem allocator is fully available. + */ + #ifdef CONFIG_EARLY_PRINTK { char *s = strstr(*cmdline_p, "earlyprintk="); _