On Mon, 13 Apr 2009 16:45:17 -0700 Dan Malek <dan@xxxxxxxxxxxxxxxxx> wrote: > On Apr 13, 2009, at 4:08 PM, Andrew Morton wrote: > > > We've run into problems in the past where a percentage number is too > > coarse on large-memory systems. > > > > Proabably that won't be an issue here, but I invite you to convince us > > of this ;) > > The challenge here is that the absolute limit of the memcg can > be dynamically changed, so I wanted to avoid a couple of problems. > One is just a system configuration error where someone forgets > to modify both. For example, if you start with the memcg limit of 100M, > and the notification limit to 80M, then come back and change the memcg > limit to 90M (or worse, < 80M) you now have a clearly incorrect > configuration. Another problem is the operation isn't atomic, at some > point during the changes, even if you remember to do it correctly, you > will have the two values not representing what you really want. It > could trigger an erroneous notification, or simply OOM kill before you > get the configuration correct. > > If an integer number turns out to not be sufficient, we could change > this > to some fixed point representation and adjust the arithmetic in the > tests. > I believe the integer number will be fine, even in large memory systems. > This is just a notification model, if we want something more fine > grained > I believe it would need different semantics. I agree. But it would be a mighty mess if we were to turn around in two years time and add a second centi-percent interface. So we should give this careful thought now and really convince ourselves that we will never ever ever want sub-1% resolution. _______________________________________________ Containers mailing list Containers@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linux-foundation.org/mailman/listinfo/containers