On 09/26/2012 09:44 PM, Tejun Heo wrote: > Hello, Glauber. > > On Wed, Sep 26, 2012 at 10:36 AM, Glauber Costa <glommer@xxxxxxxxxxxxx> wrote: >> This was discussed multiple times. Our interest is to preserve existing >> deployed setup, that were tuned in a world where kmem didn't exist. >> Because we also feed kmem to the user counter, this may very well >> disrupt their setup. > > So, that can be served by .kmem_accounted at root, no? > >> User memory, unlike kernel memory, may very well be totally in control >> of the userspace application, so it is not unreasonable to believe that >> extra pages appearing in a new kernel version may break them. >> >> It is actually a much worse compatibility problem than flipping >> hierarchy, in comparison > > Again, what's wrong with one switch at the root? > I understand your trauma about over flexibility, and you know I share of it. But I don't think there is any need to cap it here. Given kmem accounted is perfectly hierarchical, and there seem to be plenty of people who only care about user memory, I see no reason to disallow a mixed use case here. I must say that for my particular use case, enabling it unconditionally would just work, so it is not that what I have in mind. -- 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>