On Thu, 21 Feb 2013 16:21:37 -0600 Seth Jennings <sjenning@xxxxxxxxxxxxxxxxxx> wrote: > On 02/21/2013 02:36 PM, Cody P Schafer wrote: > > On Wed, Feb 20, 2013 at 04:04:41PM -0600, Seth Jennings wrote: > >> diff --git a/mm/zsmalloc.c b/mm/zsmalloc.c > >> +#define MAX(a, b) ((a) >= (b) ? (a) : (b)) > >> +/* ZS_MIN_ALLOC_SIZE must be multiple of ZS_ALIGN */ > >> +#define ZS_MIN_ALLOC_SIZE \ > >> + MAX(32, (ZS_MAX_PAGES_PER_ZSPAGE << PAGE_SHIFT >> OBJ_INDEX_BITS)) > > > > Could you use the max(a,b) defined in include/linux/kernel.h? > > > > Andrew Morton made the same point. We can't use max() or max_t() > because the value of ZS_MIN_ALLOC_SIZE is used to derive the value of > ZS_SIZE_CLASSES which is used to size an array in struct zs_pool. > > So the expression must be completely evaluated to a number by the > precompiler. Well yes, but the kernel doesn't need eight(!) separate implementations of #define MAX(a, b) ((a) > (b) ? (a) : (b)) -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>