From mboxrd@z Thu Jan 1 00:00:00 1970 From: =?ISO-8859-1?Q?Michel_D=E4nzer?= Subject: Re: [PATCH 1/3] drm/radeon: stop poisoning the GART TLB Date: Mon, 23 Jun 2014 17:15:26 +0900 Message-ID: <53A7E21E.1000000@daenzer.net> References: <1401888598-1961-1-git-send-email-deathsimple@vodafone.de> <5398218A.4040104@vodafone.de> <53998D99.6050008@vodafone.de> <539B1CA0.6010600@vodafone.de> <539D9601.8090308@vodafone.de> <53A2415D.6020808@daenzer.net> <53A2B155.4000001@vodafone.de> Mime-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Return-path: Received: from mail.gna.ch (darkcity.gna.ch [195.226.6.51]) by gabe.freedesktop.org (Postfix) with ESMTP id 114076E17B for ; Mon, 23 Jun 2014 01:15:34 -0700 (PDT) In-Reply-To: <53A2B155.4000001@vodafone.de> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" To: =?ISO-8859-1?Q?Christian_K=F6nig?= , Alex Deucher Cc: dri-devel List-Id: dri-devel@lists.freedesktop.org On 19.06.2014 18:45, Christian K=F6nig wrote: > Am 19.06.2014 03:48, schrieb Michel D=E4nzer: >> On 15.06.2014 21:48, Christian K=F6nig wrote: >>> >>> No idea what goes wrong when Marek runs piglit, but 3.15.0+"stop >>> poisoning the GART TLB"+"force_gtt" is rock solid here. >> FWIW, 3.15 doesn't survive piglit on my Bonaire either, but 3.14 is >> fine. 3.15 seems stable on Kaveri though, but I haven't tried the >> force_gtt patch on that yet. > = > Yeah, I think it's just me who has a stable system with 3.15 and that > annoys me quite a bit. FWIW though, my Kaveri doesn't always survive piglit either, e.g. this morning it didn't once again, then did after a reboot. (That's using SDMA; Kaveri was never switched back to CPDMA) > No idea what's the difference. What versions of LLVM/Mesa/Piglit are you > using for the test? Current Git of everything. >> There have also been a number of bug reports about stability regressions >> in 3.15 on various SI and CIK cards. It seems likely that at least some >> of those are related to this issue as well. >> >> If we can't figure out the problem soon, we probably need to revert the >> 'Use normal BOs for page tables' and dependent changes at least for >> 3.15.y? > = > I thought about this for the whole 3.15 release cycle, but decided > against it. But what we could do is applying the attached trivial patch, > it pins down the page tables and so pretty much reverts to the old > behavior. This patch applied on top of 3.15 + stop poisoning the GART TLB doesn't seem to help on my Bonaire, unfortunately. > I think even when we revert to the old code we have a couple of unsolved > problems with the VM support or in the driver in general where we should > try to understand the underlying reason for it instead of applying more > workarounds. I'm not suggesting applying more workarounds but going back to a known more stable state. It seems like we've maneuvered ourselves to a rather uncomfortable position from there, with no clear way to a better place. But if we basically started from the 3.14 state again, we have a few known hurdles like mine and Marek's Bonaire etc. which we know any further improvements will have to pass before they can be considered for general consumption. -- = Earthling Michel D=E4nzer | http://www.amd.com Libre software enthusiast | Mesa and X developer