On Tue, 9 Jun 2015 20:11:25 -0500 (CDT) Christoph Lameter <cl@xxxxxxxxx> wrote: > On Tue, 9 Jun 2015, Andrew Morton wrote: > > > Well I like it, even though it's going to cause a zillion little cleanup > > patches. > > > > checkpatch already has a "kfree(NULL) is safe and this check is > > probably not required" test so I guess Joe will need to get busy ;) > > > > I'll park these patches until after 4.1 is released - it's getting to > > that time... > > Why do this at all? For the third time: because there are approx 200 callsites which are already doing it. > I understand that kfree/kmem_cache_free can take a > null pointer but this is the destruction of a cache and it usually > requires multiple actions to clean things up and these actions have to be > properly sequenced. All other processors have to stop referencing this > cache before it can be destroyed. I think failing if someone does > something strange like doing cache destruction with a NULL pointer is > valuable. More than half of the kmem_cache_destroy() callsites are declining that value by open-coding the NULL test. That's reality and we should recognize it. -- 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>