Re: [PATCH v2 net-next 0/4] bpf: bpf_htab: Add BPF_MAP_TYPE_PERCPU_HASH

From: Martin KaFai Lau <redacted>
Date: Tue, 12 Jan 2016 00:20:48 -0800

BPF + kprobe is very useful in statistics collection.  In particular,
bpf is strong in doing aggregation within the kernel instead of
outputting a lot of raw samples to the userspace.

In some cases, bumping a counter/value of a particular key will have
noticeable impact.  For example, doing statistics collection
on received packets and aggregating them by network
prefix (like /64 in IPv6).  Having a percpu value can help.

Please:

	http://marc.info/?l=linux-netdev&m=145248145925834&w=2

Thanks.