On 08/21/2012 11:54 AM, Michal Hocko wrote: > On Fri 17-08-12 14:36:00, Glauber Costa wrote: >> On 08/17/2012 02:35 PM, Michal Hocko wrote: >>>>> 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? >> >> Well, we account even without a limit for user accounting. This is a >> fundamental difference, no ? > > Yes, user memory accounting is either on or off all the time (switchable > at boot time). > My understanding of kmem is that the feature is off by default because > it brings an overhead that is worth only special use cases. And that > sounds good to me. I do not see a good reason to have runtime switch > off. It makes the code more complicated for no good reason. E.g. how do > you handle charges you left behind? Say you charged some pages for > stack? > Answered in your other e-mail. About the code complication, yes, it does make the code more complicated. See below. > But maybe you have a good use case for that? > Honestly, I don't. For my particular use case, this would be always on, and end of story. I was operating under the belief that being able to say "Oh, I regret", and then turning it off would be beneficial, even at the expense of the - self contained - complication. For the general sanity of the interface, it is also a bit simpler to say "if kmem is unlimited, x happens", which is a verifiable statement, than to have a statement that is dependent on past history. But all of those need of course, as you pointed out, to be traded off by the code complexity. I am fine with either, I just need a clear sign from you guys so I don't keep deimplementing and reimplementing this forever. -- 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>