From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753658AbbJSIz2 (ORCPT ); Mon, 19 Oct 2015 04:55:28 -0400 Received: from www62.your-server.de ([213.133.104.62]:51250 "EHLO www62.your-server.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752092AbbJSIzZ (ORCPT ); Mon, 19 Oct 2015 04:55:25 -0400 Message-ID: <5624AFFA.2010209@iogearbox.net> Date: Mon, 19 Oct 2015 10:55:22 +0200 From: Daniel Borkmann User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Thunderbird/31.4.0 MIME-Version: 1.0 To: yalin wang , ast@kernel.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [RFC] bpf: change bpf syacall to use u64 temp variables References: <1445238646-9379-1-git-send-email-yalin.wang2010@gmail.com> In-Reply-To: <1445238646-9379-1-git-send-email-yalin.wang2010@gmail.com> Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit X-Authenticated-Sender: daniel@iogearbox.net Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 10/19/2015 09:10 AM, yalin wang wrote: > This patch change map_lookup_elem() and map_update_elem() function > to use u64 temp variable if the key_size or value_size is less than > u64, we don't need use kmalloc() for these small variables. > > Signed-off-by: yalin wang From an application PoV that has to make the bpf(2) syscall, how much do we actually gain from this? I'm curious, did you perform some benchmarks that show a noticeable difference?