Hello, On Tue, Mar 13, 2018 at 02:47:45PM -0700, Alexei Starovoitov wrote: > it has to be zero lookups. If idr lookup is involved, it's cleaner > to add idr as new bpf map type and use cgroup ino as an id. Oh, idr (or rather ida) is just to allocate the key, once the key is there it pretty much should boil down to sth like rcu_read_lock(); table = rcu_deref(cgrp->table); if (key < table->len) ret = table[key]; else ret = NULL; rcu_read_unlock(); Depending on the requirements, we can get rid of the table->len check by making key alloc path more expensive (ie. give out key only after table extension is fully done and propagated). Thanks. -- tejun -- To unsubscribe from this list: send the line "unsubscribe cgroups" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html