-----Original Message-----
From: Intel-gfx <intel-gfx-boun...@lists.freedesktop.org> On Behalf Of Brian
Geffon
Sent: Monday, January 27, 2025 12:44 PM
To: intel-...@lists.freedesktop.org
Cc: Wilson, Chris P <chris.p.wil...@intel.com>; Saarinen, Jani
<jani.saari...@intel.com>; Mistat, Tomasz <tomasz.mis...@intel.com>; Srinivas,
Vidya <vidya.srini...@intel.com>; ville.syrj...@linux.intel.com;
jani.nik...@linux.intel.com; linux-ker...@vger.kernel.org;
dri-devel@lists.freedesktop.org; Joonas Lahtinen
<joonas.lahti...@linux.intel.com>; Brian Geffon <bgef...@google.com>;
sta...@vger.kernel.org; Tomasz Figa <tf...@google.com>
Subject: [PATCH v3] drm/i915: Fix page cleanup on DMA remap failure
>
> When converting to folios the cleanup path of shmem_get_pages() was
> missed. When a DMA remap fails and the max segment size is greater than
> PAGE_SIZE it will attempt to retry the remap with a PAGE_SIZEd segment
> size. The cleanup code isn't properly using the folio apis and as a
> result isn't handling compound pages correctly.
>
> v2 -> v3:
> (Ville) Just use shmem_sg_free_table() as-is in the failure path of
> shmem_get_pages(). shmem_sg_free_table() will clear mapping unevictable
> but it will be reset when it retries in shmem_sg_alloc_table().
>
> v1 -> v2:
> (Ville) Fixed locations where we were not clearing mapping unevictable.
>
> Cc: sta...@vger.kernel.org
> Cc: Ville Syrjala <ville.syrj...@linux.intel.com>
> Cc: Vidya Srinivas <vidya.srini...@intel.com>
> Link: https://gitlab.freedesktop.org/drm/i915/kernel/-/issues/13487
> Link: https://lore.kernel.org/lkml/20250116135636.410164-1-bgef...@google.com/
> Fixes: 0b62af28f249 ("i915: convert shmem_sg_free_table() to use a
> folio_batch")
> Signed-off-by: Brian Geffon <bgef...@google.com>
> Suggested-by: Tomasz Figa <tf...@google.com>
Seems good to me.
Reviewed-by: Jonathan Cavitt <jonathan.cav...@intel.com>
-Jonathan Cavitt
> ---
> drivers/gpu/drm/i915/gem/i915_gem_shmem.c | 6 +-----
> 1 file changed, 1 insertion(+), 5 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/gem/i915_gem_shmem.c
> b/drivers/gpu/drm/i915/gem/i915_gem_shmem.c
> index fe69f2c8527d..ae3343c81a64 100644
> --- a/drivers/gpu/drm/i915/gem/i915_gem_shmem.c
> +++ b/drivers/gpu/drm/i915/gem/i915_gem_shmem.c
> @@ -209,8 +209,6 @@ static int shmem_get_pages(struct drm_i915_gem_object
> *obj)
> struct address_space *mapping = obj->base.filp->f_mapping;
> unsigned int max_segment = i915_sg_segment_size(i915->drm.dev);
> struct sg_table *st;
> - struct sgt_iter sgt_iter;
> - struct page *page;
> int ret;
>
> /*
> @@ -239,9 +237,7 @@ static int shmem_get_pages(struct drm_i915_gem_object
> *obj)
> * for PAGE_SIZE chunks instead may be helpful.
> */
> if (max_segment > PAGE_SIZE) {
> - for_each_sgt_page(page, sgt_iter, st)
> - put_page(page);
> - sg_free_table(st);
> + shmem_sg_free_table(st, mapping, false, false);
> kfree(st);
>
> max_segment = PAGE_SIZE;
> --
> 2.48.1.262.g85cc9f2d1e-goog
>
>
