From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755448AbdEHPTO (ORCPT ); Mon, 8 May 2017 11:19:14 -0400 Received: from mail-it0-f51.google.com ([209.85.214.51]:38908 "EHLO mail-it0-f51.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755325AbdEHPTL (ORCPT ); Mon, 8 May 2017 11:19:11 -0400 Subject: Re: [PATCH] drm/i915: Make vblank evade warnings optional To: "Syrjala, Ville" , intel-gfx , dri-devel , Linux Kernel Mailing List , Jani Nikula , Dave Airlie , Linus Torvalds , Maarten Lankhorst References: <20170507171252.5149-1-ville.syrjala@linux.intel.com> <3c44fef6-751a-b322-3b84-eef192012606@kernel.dk> <20170508072536.pgassg5phmx2a6mg@phenom.ffwll.local> From: Jens Axboe Message-ID: Date: Mon, 8 May 2017 09:19:08 -0600 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:45.0) Gecko/20100101 Thunderbird/45.8.0 MIME-Version: 1.0 In-Reply-To: <20170508072536.pgassg5phmx2a6mg@phenom.ffwll.local> Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 05/08/2017 01:25 AM, Daniel Vetter wrote: > On Sun, May 07, 2017 at 07:52:14PM -0600, Jens Axboe wrote: >> On 05/07/2017 11:56 AM, Daniel Vetter wrote: >>> On Sun, May 7, 2017 at 7:46 PM, Jens Axboe wrote: >>>> On 05/07/2017 11:12 AM, ville.syrjala@linux.intel.com wrote: >>>>> From: Ville Syrjälä >>>>> >>>>> Add a new Kconfig option to enable/disable the extra warnings >>>>> from the vblank evade code. For now we'll keep the warning >>>>> about an actually missed vblank always enabled as that can have >>>>> an actual user visible impact. But if we miss the deadline >>>>> othrwise there's no real need to bother the user with that. >>>>> We'll want these warnings enabled during development however >>>>> so that we can catch regressions. >>>>> >>>>> Based on the reports it looks like this is still very easy >>>>> to hit on SKL, so we have more work ahead of us to optimize >>>>> the crtiical section further. >>>> >>>> Shouldn't it just be a debug printk or something instead, so that normal >>>> people don't see it, but the folks that turn on debugging can get the >>>> info they need? Seems silly to add a kconfig option for this. >>> >>> I guess we could keep it as debug for users, but we want to make this >>> a hard failure on our CI machines. Kconfig knob is the easiest to roll >>> out to all machines. >> >> Wouldn't a module parameter be more useful then, as an opt-in >> to catch these violations. >> >> Nobody is going to know wtf to set this kconfig option to. > > They're all hidden behind an overall i915 debugging option which tells you > not to enable it. You won't see this. OK, that does improve things a bit. -- Jens Axboe