Hi Christian, On 04/09/2018 07:48 AM, Christian König wrote: > Am 06.04.2018 um 17:30 schrieb Jean-Marc Valin: >> Hi Christian, >> >> Is there a way to turn off these huge pages at boot-time/run-time? > > Only at compile time by not setting CONFIG_TRANSPARENT_HUGEPAGE. Any reason why echo never > /sys/kernel/mm/transparent_hugepage/enabled doesn't solve the problem? Also, I assume that disabling CONFIG_TRANSPARENT_HUGEPAGE will disable them for everything and not just what your patch added, right? >> I'm not sure what you mean by "We mitigated the problem by avoiding the >> slow coherent DMA code path on almost all platforms on newer kernels". I >> tested up to 4.16 and the performance regression is just as bad as it is >> for 4.15. > > Indeed 4.16 still doesn't have that. You could use the > amd-staging-drm-next branch or wait for 4.17. Is there a way to pull just that change or is there too much interactions with other changes? > That isn't related to the GFX hardware, but to your CPU/motherboard and > whatever else you have in the system. Well, I have an nvidia GPU in the same system (normally only used for CUDA) and if I use it instead of my RX 560 then I'm not seeing any performance issue with 4.15. > Some part of your system needs SWIOTLB and that makes allocating memory > much slower. What would that part be? FTR, I have a complete description of my system at https://jmvalin.dreamwidth.org/15583.html I don't know if it's related, but I can maybe see one thing in common between my machine and the Core 2 Quad from the other bug report and that's the "NUMA part". I have a dual-socket Xeon and (AFAIK) the Core 2 Quad is made of two two-core CPUs glued together with little communication between them. > Intel doesn't use TTM because they don't have dedicated VRAM, but the > open source nvidia driver should be affected as well. I'm using the proprietary nvidia driver (because CUDA). Is that supposed to be affected as well? > We already mitigated that problem and I don't see any solution which > will arrive faster than 4.17. Is that supposed to make the slowdown unnoticeable or just slightly better? > The only quick workaround I can see is to avoid firefox, chrome for > example is reported to work perfectly fine. Or use an unaffected GPU/driver ;-) Cheers, Jean-Marc _______________________________________________ dri-devel mailing list dri-devel@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/dri-devel
