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 215D7C433E6 for ; Fri, 12 Feb 2021 13:53:59 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id E1CC564E7D for ; Fri, 12 Feb 2021 13:53:58 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231569AbhBLNxq (ORCPT ); Fri, 12 Feb 2021 08:53:46 -0500 Received: from vps0.lunn.ch ([185.16.172.187]:36838 "EHLO vps0.lunn.ch" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230515AbhBLNxk (ORCPT ); Fri, 12 Feb 2021 08:53:40 -0500 Received: from andrew by vps0.lunn.ch with local (Exim 4.94) (envelope-from ) id 1lAYsO-005py6-6x; Fri, 12 Feb 2021 14:52:52 +0100 Date: Fri, 12 Feb 2021 14:52:52 +0100 From: Andrew Lunn To: Marcin Wojtas Cc: Stefan Chulski , David Miller , "netdev@vger.kernel.org" , "thomas.petazzoni@bootlin.com" , Nadav Haklai , Yan Markman , "linux-kernel@vger.kernel.org" , "kuba@kernel.org" , "linux@armlinux.org.uk" , "rmk+kernel@armlinux.org.uk" , "atenart@kernel.org" , "devicetree@vger.kernel.org" , "robh+dt@kernel.org" , "sebastian.hesselbarth@gmail.com" , "gregory.clement@bootlin.com" , "linux-arm-kernel@lists.infradead.org" Subject: Re: [EXT] Re: [PATCH v12 net-next 12/15] net: mvpp2: add BM protection underrun feature support Message-ID: References: <1612950500-9682-1-git-send-email-stefanc@marvell.com> <1612950500-9682-13-git-send-email-stefanc@marvell.com> <20210210.152924.767175240247395907.davem@davemloft.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org > > Or we have also found out, that pushing back on parameters like this, > > the developers goes back and looks at the code, and sometimes figures > > out a way to automatically do the right thing, removing the > > configuration knob, and just making it all simpler for the user to > > use. > > I think of 2 alternatives: > * `ethtool --set-priv-flags` - in such case there is a question if > switching this particular feature in runtime is a good idea. > * New DT/ACPI property - it is a hardware feature after all, so maybe > let the user decide whether to enable it on the platform description > level. Does this even need to be configurable? What is the cost of turning it on? How does having less pools affect the system? Does average latency go up? When would i consider an underrun actually a good thing? Maybe it should just be hard coded on? Or we should try to detect when underruns are happening a lot, and dynamically turn it on for a while? Andrew