From mboxrd@z Thu Jan 1 00:00:00 1970 From: Chris Wilson Subject: Re: [PATCH 1/6] drm/i915: hangcheck robustification Date: Wed, 19 Oct 2011 16:48:17 +0100 Message-ID: References: <1318343954-14607-1-git-send-email-daniel.vetter@ffwll.ch> <20111019080257.2d1828b0@bwidawsk.net> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Received: from mga01.intel.com (mga01.intel.com [192.55.52.88]) by gabe.freedesktop.org (Postfix) with ESMTP id E244C9E8AE for ; Wed, 19 Oct 2011 08:48:20 -0700 (PDT) In-Reply-To: <20111019080257.2d1828b0@bwidawsk.net> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: intel-gfx-bounces+gcfxdi-intel-gfx=m.gmane.org@lists.freedesktop.org Errors-To: intel-gfx-bounces+gcfxdi-intel-gfx=m.gmane.org@lists.freedesktop.org To: Ben Widawsky Cc: Daniel Vetter , intel-gfx List-Id: intel-gfx@lists.freedesktop.org On Wed, 19 Oct 2011 08:02:57 -0700, Ben Widawsky wrote: > On Wed, 19 Oct 2011 12:32:25 +0100 > Chris Wilson wrote: > > NAK: This failed to detect a hang, leaving my box frozen. I suspect that > > the value of INSTDONE was fluctuating on the render ring even though we > > had now requests pending and so could assume that it was idle. > > -Chris > > > How is that different than the previous behavior? We checked instdone on > the render ring before this patch too. As mentioned on irc, that is probably a wild goose chase. This is the first false negative I have observed with hangcheck, so I blame the robustification patch (as being a self-grandeous patch ;-). A false negative has much worse consequences than a false positive - so we need to be sure we can avoid such at any cost. -Chris -- Chris Wilson, Intel Open Source Technology Centre