On 07/17/2012 07:11 PM, Christoph Lameter wrote: > On Tue, 17 Jul 2012, Pekka Enberg wrote: > >> Well, even SLUB checks for !name in mainline so that's definitely >> worth including unconditionally. Furthermore, the size related checks >> certainly make sense and I don't see any harm in having them as well. > > There is a WARN_ON() there and then it returns NULL!!! Crazy. Causes a > NULL pointer dereference later in the caller? > It obviously depends on the caller. Although most of the calls to kmem_cache_create are made from static data, we can't assume that. Of course whoever is using static data should do those very same tests from the outside to be safe, but in case they do not, this seems to fall in the category of things that make debugging easier - even if we later on get to a NULL pointer dereference. Your mentioned bias towards minimum code size, however, is totally valid, IMHO. But I doubt those checks would introduce a huge footprint. I would imagine you being much more concerned about being able to wipe out entire subsystems like memcg, which will give you a lot more. -- 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>