From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-3.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 0B007C47094 for ; Mon, 14 Jun 2021 19:51:20 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id EA94E611C0 for ; Mon, 14 Jun 2021 19:51:19 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234593AbhFNTxV (ORCPT ); Mon, 14 Jun 2021 15:53:21 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:42506 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234214AbhFNTxQ (ORCPT ); Mon, 14 Jun 2021 15:53:16 -0400 Received: from mail.monkeyblade.net (shards.monkeyblade.net [IPv6:2620:137:e000::1:9]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 7C800C061574; Mon, 14 Jun 2021 12:51:13 -0700 (PDT) Received: from localhost (unknown [IPv6:2601:601:9f00:477::3d5]) by mail.monkeyblade.net (Postfix) with ESMTPSA id 251124D079864; Mon, 14 Jun 2021 12:51:12 -0700 (PDT) Date: Mon, 14 Jun 2021 12:51:11 -0700 (PDT) Message-Id: <20210614.125111.1519954686951337716.davem@davemloft.net> To: mcroce@linux.microsoft.com Cc: netdev@vger.kernel.org, linux-kernel@vger.kernel.org, linux-riscv@lists.infradead.org, peppe.cavallaro@st.com, alexandre.torgue@foss.st.com, kuba@kernel.org, palmer@dabbelt.com, paul.walmsley@sifive.com, drew@beagleboard.org, kernel@esmil.dk Subject: Re: [PATCH net-next] stmmac: align RX buffers From: David Miller In-Reply-To: <20210614022504.24458-1-mcroce@linux.microsoft.com> References: <20210614022504.24458-1-mcroce@linux.microsoft.com> X-Mailer: Mew version 6.8 on Emacs 27.1 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-4.6.2 (mail.monkeyblade.net [0.0.0.0]); Mon, 14 Jun 2021 12:51:12 -0700 (PDT) Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org But thois means the ethernet header will be misaliugned and this will kill performance on some cpus as misaligned accessed are resolved wioth a trap handler. Even on cpus that don't trap, the access will be slower. Thanks. From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-4.0 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id EECE7C2B9F4 for ; Mon, 14 Jun 2021 19:51:36 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id ADD3B610A0 for ; Mon, 14 Jun 2021 19:51:36 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org ADD3B610A0 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=davemloft.net Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-riscv-bounces+linux-riscv=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:Mime-Version:References:In-Reply-To: From:Subject:Cc:To:Message-Id:Date:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=lfmuzSbYrXAzmcQYrkGO94EciDmhvNhCb8X5LdSSjTQ=; b=UmBi2YU7CidyIe mSjvgYir9EzWTPgnIdhPt0ocmEPHHoHkWJhiUZZUEnh1lc3wIXEOsKIks6fyAPvTD2qvsg0qY77iB uWi7ZZTtQfRLH5C+GuyVRM/WSozegjGJf96WLqu1twxVD9oBQQ2xyq97jMlgy1tfQPZQaJHzqTcnC UjzJVqe5cHbBF5HS970mwLX6XFUVRyJA8QtMd1AxAedUclrDAGabWYzbwM2Q3SGRCurrnM/ZyImuA MRRUvUzhEjHLk481s811qaO0zkvIbj3nrhmleQZOWzITYTwm5Q4h1rjSWz4GJ2qgiAWOe4rIyesSY LUeg5CC7KHI4nXf2bC0Q==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1lssc8-00Fwom-C1; Mon, 14 Jun 2021 19:51:16 +0000 Received: from shards.monkeyblade.net ([23.128.96.9] helo=mail.monkeyblade.net) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1lssc6-00FwoE-Cv for linux-riscv@lists.infradead.org; Mon, 14 Jun 2021 19:51:15 +0000 Received: from localhost (unknown [IPv6:2601:601:9f00:477::3d5]) by mail.monkeyblade.net (Postfix) with ESMTPSA id 251124D079864; Mon, 14 Jun 2021 12:51:12 -0700 (PDT) Date: Mon, 14 Jun 2021 12:51:11 -0700 (PDT) Message-Id: <20210614.125111.1519954686951337716.davem@davemloft.net> To: mcroce@linux.microsoft.com Cc: netdev@vger.kernel.org, linux-kernel@vger.kernel.org, linux-riscv@lists.infradead.org, peppe.cavallaro@st.com, alexandre.torgue@foss.st.com, kuba@kernel.org, palmer@dabbelt.com, paul.walmsley@sifive.com, drew@beagleboard.org, kernel@esmil.dk Subject: Re: [PATCH net-next] stmmac: align RX buffers From: David Miller In-Reply-To: <20210614022504.24458-1-mcroce@linux.microsoft.com> References: <20210614022504.24458-1-mcroce@linux.microsoft.com> X-Mailer: Mew version 6.8 on Emacs 27.1 Mime-Version: 1.0 X-Greylist: Sender succeeded SMTP AUTH, not delayed by milter-greylist-4.6.2 (mail.monkeyblade.net [0.0.0.0]); Mon, 14 Jun 2021 12:51:12 -0700 (PDT) X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20210614_125114_451317_73A0F776 X-CRM114-Status: UNSURE ( 2.93 ) X-CRM114-Notice: Please train this message. X-BeenThere: linux-riscv@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-riscv" Errors-To: linux-riscv-bounces+linux-riscv=archiver.kernel.org@lists.infradead.org But thois means the ethernet header will be misaliugned and this will kill performance on some cpus as misaligned accessed are resolved wioth a trap handler. Even on cpus that don't trap, the access will be slower. Thanks. _______________________________________________ linux-riscv mailing list linux-riscv@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-riscv