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=-0.8 required=3.0 tests=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 F043EC3F2D1 for ; Wed, 4 Mar 2020 18:12:31 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id CFBA524654 for ; Wed, 4 Mar 2020 18:12:31 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727804AbgCDSMb (ORCPT ); Wed, 4 Mar 2020 13:12:31 -0500 Received: from mga03.intel.com ([134.134.136.65]:60560 "EHLO mga03.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725795AbgCDSMa (ORCPT ); Wed, 4 Mar 2020 13:12:30 -0500 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga008.jf.intel.com ([10.7.209.65]) by orsmga103.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 04 Mar 2020 10:12:30 -0800 X-IronPort-AV: E=Sophos;i="5.70,514,1574150400"; d="scan'208";a="234120338" Received: from ahduyck-desk1.jf.intel.com ([10.7.198.76]) by orsmga008-auth.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 04 Mar 2020 10:12:30 -0800 Message-ID: <45b3c493c3ce4aa79f882a8170f3420d348bb61e.camel@linux.intel.com> Subject: Re: [PATCH net-next v2 01/12] ethtool: add infrastructure for centralized checking of coalescing parameters From: Alexander Duyck To: Jakub Kicinski , Michal Kubecek Cc: davem@davemloft.net, thomas.lendacky@amd.com, benve@cisco.com, _govind@gmx.com, pkaustub@cisco.com, peppe.cavallaro@st.com, alexandre.torgue@st.com, joabreu@synopsys.com, snelson@pensando.io, yisen.zhuang@huawei.com, salil.mehta@huawei.com, jeffrey.t.kirsher@intel.com, jacob.e.keller@intel.com, michael.chan@broadcom.com, saeedm@mellanox.com, leon@kernel.org, netdev@vger.kernel.org Date: Wed, 04 Mar 2020 10:12:30 -0800 In-Reply-To: <20200304100050.14a95c36@kicinski-fedora-PC1C0HJN> References: <20200304043354.716290-1-kuba@kernel.org> <20200304043354.716290-2-kuba@kernel.org> <20200304075926.GH4264@unicorn.suse.cz> <20200304100050.14a95c36@kicinski-fedora-PC1C0HJN> Content-Type: text/plain; charset="UTF-8" User-Agent: Evolution 3.32.5 (3.32.5-1.fc30) MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org On Wed, 2020-03-04 at 10:00 -0800, Jakub Kicinski wrote: > On Wed, 4 Mar 2020 08:59:26 +0100 Michal Kubecek wrote: > > Just an idea: perhaps we could use the fact that struct ethtool_coalesce > > is de facto an array so that this block could be replaced by a loop like > > > > u32 supported_types = dev->ethtool_ops->coalesce_types; > > const u32 *values = &coalesce->rx_coalesce_usecs; > > > > for (i = 0; i < __ETHTOOL_COALESCE_COUNT; i++) > > if (values[i] && !(supported_types & BIT(i))) > > return false; > > > > and to be sure, BUILD_BUG_ON() or static_assert() check that the offset > > of ->rate_sample_interval matches ETHTOOL_COALESCE_RATE_SAMPLE_INTERVAL. > > I kind of prefer the greppability over the saved 40 lines :( > But I'm happy to change if we get more votes for the more concise > version. Or perhaps the Intel version with the warnings printed. I agree that it would make more sense to replace the types with an enum definition, and then use the enum to define bits to be used by the drivers. > > > + return !dev->ethtool_ops->coalesce_types || > > > + (dev->ethtool_ops->coalesce_types & used_types) == used_types; > > > +} > > > > I suggest to move the check for !dev->ethtool_ops->coalesce_types to the > > beginning of the function so that we avoid calculating the bitmap if we > > are not going to check it anyway. > > Good point! So one thing I just wanted to point out. The used_types won't necessarily be correct because it is only actually checking for non-zero types. There are some of these values where a zero is a valid input and the driver will accept it, such as rx_coalesce_usecs for ixgbe. As such we might want to rename the value to nonzero_types instead of used_types.