Messages in this thread | | | From | Tvrtko Ursulin <> | Subject | Re: Linux 2.6.36-rc7 | Date | Fri, 8 Oct 2010 17:17:25 +0100 |
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On Friday 08 Oct 2010 16:42:06 John Stoffel wrote: > >>>>> "Eric" == Eric Paris <eparis@redhat.com> writes: > Eric> I will tell you that the way I envision it working (and being > Eric> backwards compatible) is that priority 0 is the last thing to be > Eric> serviced. If 2 things register at the same priority the order > Eric> between them getting events is unpredictable. So when an HSM > Eric> uses the interface it would use the highest priority. An AV > Eric> vendor might use (highest priority / 2) while normal inotify > Eric> like listeners would all be happy using priority 0. > > Ugh, I'd prefer that priority 0 is first (highest), but I can see how > that would make ABI problems, assuming we don't punt on releasing the > ABI now. > > So if the order is undefined now, that's not good. Well... maybe it's > acceptable, but I can see all kinds of problems cropping up. > Hopefully they're processed in order of notifier creation instead. So > if I insert a notifier, anyone who inserts a notifier after me gets > serviced after my notifier gets run. That would seem to be the > logical and sane semantics to use here. > > Again, I'm really approaching this as a SysAdmin who'd love to use > this in an HSM environment, so ordering is a *key* requirement.
Ordering by time of registration? I thought of that but it falls flat once any service needs to restart or be restarted.
Priority is also not that great concept. I may have proposed classes or something similar at some point, don't remember any more. It would be equivalent to having allocated priority ranges, like:
>1000 - pre-content >=100 - access-control <100 - content
Doesn't really solve ordering inside groups so maybe we do not need priorities at all just these three classes?
Tvrtko
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