Hi, Could you please help review this patch? Thanks, zackary
> On Thu, Aug 06, 2026 at 09:21:41PM +0800, Zhaoyu Liu wrote: > > The second loop in drm_pagemap_migrate_to_devmem() checks > > `page_pgmap(src_page) == pagemap && !can_migrate_same_pagemap` to skip > > pages already on the target pagemap. However, this condition is always > > false at this point: if can_migrate_same_pagemap is false and any own > > pages exist, the first loop already returns -EBUSY before reaching here. > > > > v2: > > - Skip the no-op migrate_vma_pages() when all pages already reside on > > the target pagemap. > > > > Signed-off-by: Zhaoyu Liu <[email protected]> > > --- > > drivers/gpu/drm/drm_pagemap.c | 21 ++++++--------------- > > 1 file changed, 6 insertions(+), 15 deletions(-) > > > > diff --git a/drivers/gpu/drm/drm_pagemap.c b/drivers/gpu/drm/drm_pagemap.c > > index 15c78eca180b..64922b944092 100644 > > --- a/drivers/gpu/drm/drm_pagemap.c > > +++ b/drivers/gpu/drm/drm_pagemap.c > > @@ -698,7 +698,7 @@ int drm_pagemap_migrate_to_devmem(struct > > drm_pagemap_devmem *devmem_allocation, > > * nothing. Raced or unknown device pages. > > */ > > err = -EBUSY; > > - goto err_aborted_migration; > > + goto direct_finalize; > > } > > > > /* Count device-private pages to migrate */ > > @@ -719,19 +719,17 @@ int drm_pagemap_migrate_to_devmem(struct > > drm_pagemap_devmem *devmem_allocation, > > if (own_pages == npages) { > > err = 0; > > drm_dbg(dpagemap->drm, "Migration wasn't necessary.\n"); > > - goto err_aborted_migration; > > + goto direct_finalize; > > } else if (own_pages && !mdetails->can_migrate_same_pagemap) { > > err = -EBUSY; > > drm_dbg(dpagemap->drm, "Migration aborted due to > > fragmentation.\n"); > > - goto err_aborted_migration; > > + goto direct_finalize; > > } > > > > err = ops->populate_devmem_pfn(devmem_allocation, npages, migrate.dst); > > if (err) > > goto err_aborted_migration; > > > > - own_pages = 0; > > - > > for (i = 0; i < npages;) { > > unsigned long j; > > struct page *page = pfn_to_page(migrate.dst[i]); > > @@ -744,12 +742,7 @@ int drm_pagemap_migrate_to_devmem(struct > > drm_pagemap_devmem *devmem_allocation, > > struct drm_pagemap_zdd *src_zdd = > > drm_pagemap_page_zone_device_data(src_page); > > > > - if (page_pgmap(src_page) == pagemap && > > - !mdetails->can_migrate_same_pagemap) { > > - migrate.dst[i] = 0; > > - own_pages++; > > - goto next; > > - } > > + /* Own or peer device private page */ > > cur.dpagemap = src_zdd->dpagemap; > > cur.ops = src_zdd->devmem_allocation->ops; > > cur.device = cur.dpagemap->drm->dev; > > @@ -786,7 +779,6 @@ int drm_pagemap_migrate_to_devmem(struct > > drm_pagemap_devmem *devmem_allocation, > > goto err_finalize; > > } > > > > -next: > > i += NR_PAGES(order); > > } > > > > @@ -797,8 +789,6 @@ int drm_pagemap_migrate_to_devmem(struct > > drm_pagemap_devmem *devmem_allocation, > > if (err) > > goto err_finalize; > > > > - drm_WARN_ON(dpagemap->drm, !!own_pages); > > - > > dma_fence_put(devmem_allocation->pre_migrate_fence); > > devmem_allocation->pre_migrate_fence = NULL; > > > > @@ -822,11 +812,12 @@ int drm_pagemap_migrate_to_devmem(struct > > drm_pagemap_devmem *devmem_allocation, > > i += nr_pages; > > } > > > > - if (!err && migrated_pages < npages - own_pages) { > > + if (!err && migrated_pages < npages) { > > drm_dbg(dpagemap->drm, "Raced while finalizing migration.\n"); > > err = -EBUSY; > > } > > > > +direct_finalize: > > migrate_vma_finalize(&migrate); > > err_free: > > drm_pagemap_zdd_put(zdd); > > -- > > 2.34.1
