From mboxrd@z Thu Jan 1 00:00:00 1970 From: Chris Wilson Subject: Re: [PATCH 39/48] drm/i915: Do not allow buffers at offset 0 Date: Thu, 12 Dec 2013 10:59:03 +0000 Message-ID: <20131212105903.GF6195@nuc-i3427.alporthouse.com> References: <20131206215521.GA6922@bwidawsk.net> <1386367941-7131-1-git-send-email-benjamin.widawsky@intel.com> <1386367941-7131-39-git-send-email-benjamin.widawsky@intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Received: from fireflyinternet.com (mail.fireflyinternet.com [87.106.93.118]) by gabe.freedesktop.org (Postfix) with ESMTP id 6E93EFA519 for ; Thu, 12 Dec 2013 02:59:10 -0800 (PST) Content-Disposition: inline In-Reply-To: <1386367941-7131-39-git-send-email-benjamin.widawsky@intel.com> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: intel-gfx-bounces@lists.freedesktop.org Errors-To: intel-gfx-bounces@lists.freedesktop.org To: Ben Widawsky Cc: Intel GFX , Ben Widawsky List-Id: intel-gfx@lists.freedesktop.org On Fri, Dec 06, 2013 at 02:11:24PM -0800, Ben Widawsky wrote: > This is primarily a band aid for an unexplainable error in > gem_reloc_vs_gpu/forked-faulting-reloc-thrashing. Essentially as soon as > a relocated buffer (which had a non-zero presumed offset) moved to > offset 0, something goes bad. Since I have been unable to solve this, > and potentially this is a good thing to do anyway, since many things can > accidentally write to offset 0, why not? A better hack would have been to exclude the first page from the vm->mm, so that we didn't then introduce a change to ggtt. -Chris -- Chris Wilson, Intel Open Source Technology Centre