On 08/17/2012 02:35 PM, Michal Hocko wrote: > On Fri 17-08-12 14:07:00, Glauber Costa wrote: >> On 08/17/2012 01:35 PM, Michal Hocko wrote: >>>>> Above you said "Once enabled, can't be disabled." and now you can >>>>>>> disable it? Say you are a leaf group with non accounted parents. This >>>>>>> will clear the flag and so no further accounting is done. Shouldn't >>>>>>> unlimited mean that we will never reach the limit? Or am I missing >>>>>>> something? >>>>>>> >>>>> >>>>> You are missing something, and maybe I should be more clear about that. >>>>> The static branches can't be disabled (it is only safe to disable them >>>>> from disarm_static_branches(), when all references are gone). Note that >>>>> when unlimited, we flip bits, do a transversal, but there is no mention >>>>> to the static branch. >>> My little brain still doesn't get this. I wasn't concerned about static >>> branches. I was worried about memcg_can_account_kmem which will return >>> false now, doesn't it. >>> >> >> Yes, it will. If I got you right, you are concerned because I said that >> can't happen. But it will. >> >> But I never said that can't happen. I said (ok, I meant) the static >> branches can't be disabled. > > Ok, then I misunderstood that because the comment was there even before > static branches were introduced and it made sense to me. This is > inconsistent with what we do for user accounting because even if we set > limit to unlimitted we still account. Why should we differ here? > There is another thing as well. Mel was right in his comment: I am actually abusing this bit (because it is flippable), and it seems the static branch can be updated more than once... I'll merge your comments, and fix this. -- 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>