linux-kernel - Re: AMD graphics performance regression in 4.15 and later

Open Source and information security mailing list archives

Message-ID: <cb69fe04-988d-b337-057d-589cb0622e84@gmail.com>
Date:   Tue, 10 Apr 2018 08:48:04 +0200
From:   Christian König <ckoenig.leichtzumerken@...il.com>
To:     Jean-Marc Valin <jmvalin@...illa.com>, christian.koenig@....com,
        airlied@...ux.ie, alexander.deucher@....com,
        Felix.Kuehling@....com, labbott@...hat.com,
        akpm@...ux-foundation.org, michel.daenzer@....com,
        dri-devel@...ts.freedesktop.org, linux-kernel@...r.kernel.org
Subject: Re: AMD graphics performance regression in 4.15 and later

Am 09.04.2018 um 17:17 schrieb Jean-Marc Valin:
> On 04/09/2018 05:42 AM, Christian König wrote:
>> Backporting all the detection logic is to invasive, but you could just
>> go into drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c and forcefull use the
>> other code path.
>>
>> Just look out for "#ifdef CONFIG_SWIOTLB" checks and disable those.
> Do you mean just taking the 4.15 code as is and replacing
> "#ifdef CONFIG_SWIOTLB" with "#if 0" in
> drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c or are you talking about using a
> different version of drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c ?

Yes, exactly. The code then won't work any more on some ARMs or systems 
with more than 1TB of memory, but I don't think you care about that :)

Christian.

>
> 	Jean-Marc
> _______________________________________________
> dri-devel mailing list
> dri-devel@...ts.freedesktop.org
> https://lists.freedesktop.org/mailman/listinfo/dri-devel

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives