On Wed, Aug 07, 2019 at 08:02:14AM -0700, Ralph Campbell wrote: > When memory is migrated to the GPU it is likely to be accessed by GPU > code soon afterwards. Instead of waiting for a GPU fault, map the > migrated memory into the GPU page tables with the same access permissions > as the source CPU page table entries. This preserves copy on write > semantics. > > Signed-off-by: Ralph Campbell <rcampbell@xxxxxxxxxx> > Cc: Christoph Hellwig <hch@xxxxxx> > Cc: Jason Gunthorpe <jgg@xxxxxxxxxxxx> > Cc: "Jérôme Glisse" <jglisse@xxxxxxxxxx> > Cc: Ben Skeggs <bskeggs@xxxxxxxxxx> > --- > > This patch is based on top of Christoph Hellwig's 9 patch series > https://lore.kernel.org/linux-mm/20190729234611.GC7171@xxxxxxxxxx/T/#u > "turn the hmm migrate_vma upside down" but without patch 9 > "mm: remove the unused MIGRATE_PFN_WRITE" and adds a use for the flag. This looks useful. I've already dropped that patch for the pending resend. > static unsigned long nouveau_dmem_migrate_copy_one(struct nouveau_drm *drm, > - struct vm_area_struct *vma, unsigned long addr, > - unsigned long src, dma_addr_t *dma_addr) > + struct vm_area_struct *vma, unsigned long src, > + dma_addr_t *dma_addr, u64 *pfn) I'll pick up the removal of the not needed addr argument for the patch introducing nouveau_dmem_migrate_copy_one, thanks, > static void nouveau_dmem_migrate_chunk(struct migrate_vma *args, > - struct nouveau_drm *drm, dma_addr_t *dma_addrs) > + struct nouveau_drm *drm, dma_addr_t *dma_addrs, u64 *pfns) > { > struct nouveau_fence *fence; > unsigned long addr = args->start, nr_dma = 0, i; > > for (i = 0; addr < args->end; i++) { > args->dst[i] = nouveau_dmem_migrate_copy_one(drm, args->vma, > - addr, args->src[i], &dma_addrs[nr_dma]); > + args->src[i], &dma_addrs[nr_dma], &pfns[i]); Nit: I find the &pfns[i] way to pass the argument a little weird to read. Why not "pfns + i"? > +u64 * > +nouveau_pfns_alloc(unsigned long npages) > +{ > + struct nouveau_pfnmap_args *args; > + > + args = kzalloc(sizeof(*args) + npages * sizeof(args->p.phys[0]), Can we use struct_size here? > + int ret; > + > + if (!svm) > + return; > + > + mutex_lock(&svm->mutex); > + svmm = nouveau_find_svmm(svm, mm); > + if (!svmm) { > + mutex_unlock(&svm->mutex); > + return; > + } > + mutex_unlock(&svm->mutex); Given that nouveau_find_svmm doesn't take any kind of reference, what gurantees svmm doesn't go away after dropping the lock? > @@ -44,5 +49,19 @@ static inline int nouveau_svmm_bind(struct drm_device *device, void *p, > { > return -ENOSYS; > } > + > +u64 *nouveau_pfns_alloc(unsigned long npages) > +{ > + return NULL; > +} > + > +void nouveau_pfns_free(u64 *pfns) > +{ > +} > + > +void nouveau_pfns_map(struct nouveau_drm *drm, struct mm_struct *mm, > + unsigned long addr, u64 *pfns, unsigned long npages) > +{ > +} > #endif /* IS_ENABLED(CONFIG_DRM_NOUVEAU_SVM) */ nouveau_dmem.c and nouveau_svm.c are both built conditional on CONFIG_DRM_NOUVEAU_SVM, so there is no need for stubs here. _______________________________________________ amd-gfx mailing list amd-gfx@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/amd-gfx
