From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754117AbcALVpm (ORCPT ); Tue, 12 Jan 2016 16:45:42 -0500 Received: from shards.monkeyblade.net ([149.20.54.216]:54326 "EHLO shards.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753342AbcALVpi (ORCPT ); Tue, 12 Jan 2016 16:45:38 -0500 Date: Tue, 12 Jan 2016 16:45:36 -0500 (EST) Message-Id: <20160112.164536.17755595447757162.davem@davemloft.net> To: kafai@fb.com Cc: netdev@vger.kernel.org, linux-kernel@vger.kernel.org, alexei.starovoitov@gmail.com, tom.leiming@gmail.com, kernel-team@fb.com Subject: Re: [PATCH v2 net-next 0/4] bpf: bpf_htab: Add BPF_MAP_TYPE_PERCPU_HASH From: David Miller In-Reply-To: <1452586852-1575604-1-git-send-email-kafai@fb.com> References: <1452586852-1575604-1-git-send-email-kafai@fb.com> X-Mailer: Mew version 6.7 on Emacs 24.5 / Mule 6.0 (HANACHIRUSATO) Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit X-Greylist: Sender succeeded SMTP AUTH, not delayed by milter-greylist-4.5.12 (shards.monkeyblade.net [149.20.54.216]); Tue, 12 Jan 2016 13:45:38 -0800 (PST) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Martin KaFai Lau 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.