Hi Nicolas, On Thu, Aug 27, 2020 at 12:36:24AM +0200, Nicolas Dichtel wrote: > Le 26/08/2020 à 20:52, Harald Welte a écrit :
> > Wouldn't it make sense to only allocate + fill those messages if we > > actually knew a subscriber existed? > > In fact, this is actually how the netlink framework works. Well, as you can tell from my responses, I've not been doing kernel work for a decade now, so I'm looking at things from a more distant and ignorant perspective. To me it seems odd to allocate memory and copy data to it (cache misses, ...) if nobody every requested that data, and nobody will ever use it. But if this is how it is supposed to work, then I will of course defer to that. All netlink would have to expose is a function that returns whether or not there are any subscribers to the given multicast group. Then all of the allocation + initialization would disappear in a branch that is not executed most of the time, at least for current, existing gtpnl systems. Yes, that means one more branch, of course. But that branch will happen later on anyway, event today: Only after the allocation + initialization. So having said the above, if this is how it is supposed to work with netlink: Acked-by: Harald Welte <lafo...@gnumonks.org> -- - Harald Welte <lafo...@gnumonks.org> http://laforge.gnumonks.org/ ============================================================================ "Privacy in residential applications is a desirable marketing option." (ETSI EN 300 175-7 Ch. A6)
