From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752831AbbJBPZY (ORCPT ); Fri, 2 Oct 2015 11:25:24 -0400 Received: from mail-pa0-f45.google.com ([209.85.220.45]:32818 "EHLO mail-pa0-f45.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752128AbbJBPZW (ORCPT ); Fri, 2 Oct 2015 11:25:22 -0400 Date: Fri, 2 Oct 2015 08:25:20 -0700 From: Alexei Starovoitov To: Nicolas Schichan Cc: Russell King , "David S. Miller" , Mircea Gherzan , Daniel Borkmann , linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, netdev@vger.kernel.org Subject: Re: [PATCH net-next V2] ARM: net: support BPF_ALU | BPF_MOD instructions in the BPF JIT. Message-ID: <20151002152519.GA1619@Alexeis-MBP.westell.com> References: <1443798407-19154-1-git-send-email-nschichan@freebox.fr> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1443798407-19154-1-git-send-email-nschichan@freebox.fr> User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Oct 02, 2015 at 05:06:47PM +0200, Nicolas Schichan wrote: > For ARMv7 with UDIV instruction support, generate an UDIV instruction > followed by an MLS instruction. > > For other ARM variants, generate code calling a C wrapper similar to > the jit_udiv() function used for BPF_ALU | BPF_DIV instructions. > > Some performance numbers reported by the test_bpf module (the duration > per filter run is reported in nanoseconds, between "jitted:" and > "PASS": > > ARMv7 QEMU nojit: test_bpf: #3 DIV_MOD_KX jited:0 2196 PASS > ARMv7 QEMU jit: test_bpf: #3 DIV_MOD_KX jited:1 104 PASS > ARMv5 QEMU nojit: test_bpf: #3 DIV_MOD_KX jited:0 2176 PASS > ARMv5 QEMU jit: test_bpf: #3 DIV_MOD_KX jited:1 1104 PASS > ARMv5 kirkwood nojit: test_bpf: #3 DIV_MOD_KX jited:0 1103 PASS > ARMv5 kirkwood jit: test_bpf: #3 DIV_MOD_KX jited:1 311 PASS > > Signed-off-by: Nicolas Schichan run-time check for zero is there, so looks good to me Acked-by: Alexei Starovoitov