Hi Andrew, After merging the akpm-current tree, today's linux-next build (x86_64 allmodconfig) failed like this: arch/x86/mm/init.c: In function 'memory_map_bottom_up': arch/x86/mm/init.c:512:18: error: 'STEP_SIZE_SHIFT' undeclared (first use in this function) step_size <<= STEP_SIZE_SHIFT; ^ Caused by commit 21376f622b03 ("x86/mem-hotplug: support initializing page tables in bottom-up mode") interacting with commit 6979287a7df6 ("x86/mm: Add 'step_size' comments to init_mem_mapping()") from the tip tree. I added the following merge fix patch: From: Stephen Rothwell Date: Fri, 27 Sep 2013 17:58:55 +1000 Subject: [PATCH] x86/mem-hotplug: fix for bad merge Signed-off-by: Stephen Rothwell --- arch/x86/mm/init.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/x86/mm/init.c b/arch/x86/mm/init.c index cb77179..58bb4e9 100644 --- a/arch/x86/mm/init.c +++ b/arch/x86/mm/init.c @@ -509,7 +509,7 @@ static void __init memory_map_bottom_up(unsigned long map_start, start = next; if (new_mapped_ram_size > mapped_ram_size) - step_size <<= STEP_SIZE_SHIFT; + step_size = get_new_step_size(step_size); mapped_ram_size += new_mapped_ram_size; } } -- 1.8.4.rc3 -- Cheers, Stephen Rothwell sfr@canb.auug.org.au