Messages in this thread | | | From | Gabriel C <> | Date | Thu, 7 Jun 2018 14:32:46 +0200 | Subject | Re: Kernel and ADM hardware roulette ( was AMD graphics performance regression in 4.15 and later ) |
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2018-06-07 9:07 GMT+02:00 Christian König <christian.koenig@amd.com>: > Am 06.06.2018 um 17:44 schrieb Gabriel C: >> >> 2018-06-06 17:03 GMT+02:00 Michel Dänzer <michel@daenzer.net>: >>> >>> On 2018-06-06 04:44 PM, Christian König wrote: >>>> >>>> Am 06.06.2018 um 16:12 schrieb Michel Dänzer: >>>> [SNIP] >>>> At least in theory it should work when we use the coherent DMA >>>> allocator. >>>> >>>> When that really worked before, so the most likely commit which broke >>>> this is: >>>> >>>> commit fd5fd480dd8fe4910546e7b080b3ae345e57fe9f >>>> Author: Chunming Zhou <david1.zhou@amd.com> >>>> Date: Fri Feb 9 10:44:09 2018 +0800 >>>> >>>> drm/amdgpu: only enable swiotlb alloc when need v2 >>>> >>>> get the max io mapping address of system memory to see if it is >>>> over >>>> our card accessing range. >>>> v2: move checking later >>>> >>>> Signed-off-by: Chunming Zhou <david1.zhou@amd.com> >>>> Reviewed-by: Monk Liu <monk.liu@amd.com> >>>> Reviewed-by: Christian König <christian.koenig@amd.com> >>>> Signed-off-by: Alex Deucher <alexander.deucher@amd.com> >>>> >>>> Currently looking into how we could somehow improve this detection. >>> >>> I guess this could fit for Gabriel, but e.g. >>> https://bugs.freedesktop.org/104437 says amdgpu was already broken with >>> SME in 4.15, if not 4.14 (I suspect there was simply no SME support >>> earlier). > > > And what I totally missed is that Gabriel is using radeon and not amdgpu. > > So Gabriel you need to revert this one for testing: > commit 1bc3d3cce8c3b44c2b5ac6cee98c830bb40e6b0f > Author: Chunming Zhou <david1.zhou@amd.com> > Date: Fri Feb 9 10:44:10 2018 +0800 > > drm/radeon: only enable swiotlb path when need v2 > > swiotlb expands our card accessing range, but its path always is slower > than ttm pool allocation. > So add condition to use it. > v2: move a bit later > > Signed-off-by: Chunming Zhou <david1.zhou@amd.com> > Reviewed-by: Monk Liu <monk.liu@amd.com> > Reviewed-by: Christian König <christian.koenig@amd.com> > Signed-off-by: Alex Deucher <alexander.deucher@amd.com> > Link: > https://patchwork.freedesktop.org/patch/msgid/20180209024410.1469-3-david1.zhou@amd.com > >> I got strange performance issue with 4.15 and 4.16 .. but SME was ON >> on that setup ( even before it hit mainline ) and never broke the GPU like >> this. > > > Well that is very interesting, you are the first one who reports that SME + > GFX works in some way. So far we only got negative reports for that. > >> There is a 4.16.13 boot dmesg which has no such issue: >> >> >> http://ftp.frugalware.org/pub/other/people/crazy/radeon/dmesg-radeon-SME-ON-kernel-4.16.txt >> >> With the setup as is booting 4.16.x works , while 4.17 trows the errors. > > > Please do the bisect if the patch I've mentioned above doesn't help.
Ok done.. bisect points to:
b468620f2a1dfdcfddfd6fa54367b8bcc1b51248 is the first bad commit commit b468620f2a1dfdcfddfd6fa54367b8bcc1b51248 Author: Christoph Hellwig <hch@lst.de> Date: Mon Mar 19 11:38:19 2018 +0100
iommu/amd_iommu: Use CONFIG_DMA_DIRECT_OPS=y and dma_direct_{alloc,free}()
This cleans up the code a lot by removing duplicate logic.
Tested-by: Tom Lendacky <thomas.lendacky@amd.com> Tested-by: Joerg Roedel <jroedel@suse.de> Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Joerg Roedel <jroedel@suse.de> Cc: David Woodhouse <dwmw2@infradead.org> Cc: Joerg Roedel <joro@8bytes.org> Cc: Jon Mason <jdmason@kudzu.us> Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Muli Ben-Yehuda <mulix@mulix.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: iommu@lists.linux-foundation.org Link: http://lkml.kernel.org/r/20180319103826.12853-8-hch@lst.de Signed-off-by: Ingo Molnar <mingo@kernel.org>
I'll try to revert this once I'm home.
BR
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