Received: by 2002:a05:6a10:8c0a:0:0:0:0 with SMTP id go10csp2953799pxb; Fri, 12 Feb 2021 05:55:51 -0800 (PST) X-Google-Smtp-Source: ABdhPJxRb7sKy3hQ8rCMgGlgpGSLFljgaORmaLWZj2Ob4aFaAiZ8qNc9tAb+sGk5k1JgHVCvUx64 X-Received: by 2002:a17:906:4a8e:: with SMTP id x14mr386775eju.445.1613138150894; Fri, 12 Feb 2021 05:55:50 -0800 (PST) ARC-Seal: i=1; a=rsa-sha256; t=1613138150; cv=none; d=google.com; s=arc-20160816; b=sW3SqLe8kW9FQ7OGGj5drNV+nJBmuNsoxGFjLzxH0zD/i6C6NZYHMbyXJ8CUICllGC pVzkdDFIwAiL8qkF2irXrEneINYDGz3TZ6DE+b7O9Y9k37b0kRVY8Jqd7/QLAdpq3LpU +M9HBXx6V2DoIj6yyKT4woQ1uaVwsypVVXCwelv7MLMnmcv2iBr+TCAU9+6LVgiF6Vfq FaE/08bdcxzfVP1wmZfiB+9w9ewsKWfUmPm5RN3vld9pk+G1Ytf0y3LHATlrECGy7eYj 0H5T3eleKxAqbo2iOR4Cc3Yl6HRqEyi2IPVJw9MVaAOmAYJwWh5LVGdJ+qaZLxXUWQ9P +hFg== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:in-reply-to:content-disposition:mime-version :references:message-id:subject:cc:to:from:date; bh=kX9Vrs6aHNay0NunpmEnMO8UfhIXqcXSCXoRKjgWSDQ=; b=QGkd5ybJ3M6mBHyuNUNQ4z5RNiFynPHWKBMq7OvoZx4sffTqTK8nCDbuk6L3LTsdzL k30RBqMyVuNKOAgSMO+uI9vf2VL5loJkBQorOHZd9UaYYvKYFcSI7HC9x7Mow2E6G2yS nfIJChP8h/wgKJvVsTEf0WUblZI40y41WbPySWbmDZhLXlerRUNBwg+fXoXYGS+8tqwV JYZ6epoMK+ICI3s2oyyO3d6rdJZdwUU6m2rbyUGSZxOzo5+/g+6PnZPHJKI++L1MuBcS wMUJM2fH4EQ2qDRknyVD4Mv3hU4vjF2v6ODNA50iaDFHBHt8v0+okqDDWOs3AVlhnwRV VrCQ== ARC-Authentication-Results: i=1; mx.google.com; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Return-Path: Received: from vger.kernel.org (vger.kernel.org. [23.128.96.18]) by mx.google.com with ESMTP id b19si6306155edd.84.2021.02.12.05.55.27; Fri, 12 Feb 2021 05:55:50 -0800 (PST) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18; Authentication-Results: mx.google.com; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231566AbhBLNxm (ORCPT + 99 others); Fri, 12 Feb 2021 08:53:42 -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