On 02/25/2016 02:48 PM, Michal Hocko wrote:
On Thu 25-02-16 13:36:11, Nikolay Borisov wrote: - if (unlikely(gfp_flags & __GFP_NOFAIL)) { - /* - * __GFP_NOFAIL is not to be used in new code. - * - * All __GFP_NOFAIL callers should be fixed so that they - * properly detect and handle allocation failures. - * - * We most definitely don't want callers attempting to - * allocate greater than order-1 page units with - * __GFP_NOFAIL. - */ - WARN_ON_ONCE(order > 1); - } + /* + * We most definitely don't want callers attempting to + * allocate greater than order-1 page units with __GFP_NOFAIL. + */ + WARN_ON_ONCE((gfp_flags & __GFP_NOFAIL) && (order > 1)); spin_lock_irqsave(&zone->lock, flags);page = NULL;
Hmm, even the reduced text (and the WARN_ON in the first place) sounds IMHO discouraging enough to make people think that opencoding a loop around such allocations is a good workaround. Yeah, we have a better/more thorough explanation around the __GFP_NOFAIL definition, but the WARN_ON will point people here.
