Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752054AbbKKAI7 (ORCPT ); Tue, 10 Nov 2015 19:08:59 -0500 Received: from mail-pa0-f49.google.com ([209.85.220.49]:35505 "EHLO mail-pa0-f49.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751123AbbKKAI6 (ORCPT ); Tue, 10 Nov 2015 19:08:58 -0500 Message-ID: <1447200535.17135.88.camel@edumazet-glaptop2.roam.corp.google.com> Subject: Re: [PATCH 2/2] arm64: bpf: add BPF XADD instruction From: Eric Dumazet To: Yang Shi Cc: ast@kernel.org, daniel@iogearbox.net, catalin.marinas@arm.com, will.deacon@arm.com, zlim.lnx@gmail.com, xi.wang@gmail.com, linux-kernel@vger.kernel.org, netdev@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linaro-kernel@lists.linaro.org Date: Tue, 10 Nov 2015 16:08:55 -0800 In-Reply-To: <1447195301-16757-3-git-send-email-yang.shi@linaro.org> References: <1447195301-16757-1-git-send-email-yang.shi@linaro.org> <1447195301-16757-3-git-send-email-yang.shi@linaro.org> Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.10.4-0ubuntu2 Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 570 Lines: 18 On Tue, 2015-11-10 at 14:41 -0800, Yang Shi wrote: > aarch64 doesn't have native support for XADD instruction, implement it by > the below instruction sequence: > > Load (dst + off) to a register > Add src to it > Store it back to (dst + off) Not really what is needed ? See this BPF_XADD as an atomic_add() equivalent. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/