On Fri, Jun 28, 2013 at 02:25:58PM -0400, Luiz Capitulino wrote:
> > > > That's how it's expected to work, because on strict mode you're notified
> > > > for the level you registered for. So apps registering for critical, will
> > > > still be notified on critical just like before.
> > >
> > > Suppose you introduce a new level, and the system hits this level. Before,
> > > the app would receive at least some notification for the given memory load
> > > (i.e. one of the old levels), with the new level introduced in the kernel,
> > > the app will receive no events at all.
>
> That's not true. If an app registered for critical it will still get
> critical notification when the system is at the critical level. Just as it
> always did. No new events will change this.
>
> With today's semantics though, new events will change when current events
> are triggered. So each new extension will cause applications to have
> different behaviors, in different kernel versions. This looks quite
> undesirable to me.
I'll try to explain it again.
Old behaviour:
low -> event
x <- but the system is at this unnamed level, between low and med
med
crit
We add a level:
low
low-med <- system at this state, we send an event, but the old app does
not know about it, so it won't receive *any* notifications. (In
older kernels it would receive low level notification
med
crit
You really don't see a problem here?
I see the problem, and I see these solutions:
1. Use current scheme.
2. Add versioning.
3. Never change the levels (how can we know?)
Anton
--
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>