On Tue, Jul 28, 2020 at 05:43:02PM -0700, Sagi Grimberg wrote: > > > > Dynamically allocating each one is possible but not very scalable. > > > > > > The question is if there is some way, we can do this with on-stack > > > or a single on-heap rcu_head or equivalent that can achieve the same > > > effect. > > > > If the hctx structures are guaranteed to stay put, you could count > > them and then do a single allocation of an array of rcu_head structures > > (or some larger structure containing an rcu_head structure, if needed). > > You could then sequence through this array, consuming one rcu_head per > > hctx as you processed it. Once all the callbacks had been invoked, > > it would be safe to free the array. > > > > Sounds too simple, though. So what am I missing? > > We don't want higher-order allocations... OK, I will bite... Do multiple lower-order allocations (page size is still lower-order, correct?) and link them together. Sorry, couldn't resist... Thanx, Paul
