| Message ID | 20240105184624.508603-13-dmitry.osipenko@collabora.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | Add generic memory shrinker to VirtIO-GPU and Panfrost DRM drivers | expand |
On Fri, 5 Jan 2024 21:46:06 +0300 Dmitry Osipenko <dmitry.osipenko@collabora.com> wrote: > Prepare drm_gem_shmem_free() to addition of memory shrinker support > to drm-shmem by adding and using variant of put_pages() that doesn't > touch reservation lock. Reservation shouldn't be touched because lockdep > will trigger a bogus warning about locking contention with fs_reclaim > code paths that can't happen during the time when GEM is freed and > lockdep doesn't know about that. > > Signed-off-by: Dmitry Osipenko <dmitry.osipenko@collabora.com> Reviewed-by: Boris Brezillon <boris.brezillon@collabora.com> > --- > drivers/gpu/drm/drm_gem_shmem_helper.c | 40 ++++++++++++++------------ > 1 file changed, 21 insertions(+), 19 deletions(-) > > diff --git a/drivers/gpu/drm/drm_gem_shmem_helper.c b/drivers/gpu/drm/drm_gem_shmem_helper.c > index 3403700780c3..799a3c5015ad 100644 > --- a/drivers/gpu/drm/drm_gem_shmem_helper.c > +++ b/drivers/gpu/drm/drm_gem_shmem_helper.c > @@ -128,6 +128,22 @@ struct drm_gem_shmem_object *drm_gem_shmem_create(struct drm_device *dev, size_t > } > EXPORT_SYMBOL_GPL(drm_gem_shmem_create); > > +static void > +drm_gem_shmem_free_pages(struct drm_gem_shmem_object *shmem) > +{ > + struct drm_gem_object *obj = &shmem->base; > + > +#ifdef CONFIG_X86 > + if (shmem->map_wc) > + set_pages_array_wb(shmem->pages, obj->size >> PAGE_SHIFT); > +#endif > + > + drm_gem_put_pages(obj, shmem->pages, > + shmem->pages_mark_dirty_on_put, > + shmem->pages_mark_accessed_on_put); > + shmem->pages = NULL; > +} > + > /** > * drm_gem_shmem_free - Free resources associated with a shmem GEM object > * @shmem: shmem GEM object to free > @@ -142,8 +158,6 @@ void drm_gem_shmem_free(struct drm_gem_shmem_object *shmem) > if (obj->import_attach) { > drm_prime_gem_destroy(obj, shmem->sgt); > } else { > - dma_resv_lock(shmem->base.resv, NULL); > - > drm_WARN_ON(obj->dev, refcount_read(&shmem->vmap_use_count)); > > if (shmem->sgt) { > @@ -152,13 +166,12 @@ void drm_gem_shmem_free(struct drm_gem_shmem_object *shmem) > sg_free_table(shmem->sgt); > kfree(shmem->sgt); > } > - if (shmem->pages) > - drm_gem_shmem_put_pages_locked(shmem); > + if (shmem->pages && > + refcount_dec_and_test(&shmem->pages_use_count)) > + drm_gem_shmem_free_pages(shmem); > > drm_WARN_ON(obj->dev, refcount_read(&shmem->pages_use_count)); > drm_WARN_ON(obj->dev, refcount_read(&shmem->pages_pin_count)); > - > - dma_resv_unlock(shmem->base.resv); > } > > drm_gem_object_release(obj); > @@ -208,21 +221,10 @@ static int drm_gem_shmem_get_pages_locked(struct drm_gem_shmem_object *shmem) > */ > void drm_gem_shmem_put_pages_locked(struct drm_gem_shmem_object *shmem) > { > - struct drm_gem_object *obj = &shmem->base; > - > dma_resv_assert_held(shmem->base.resv); > > - if (refcount_dec_and_test(&shmem->pages_use_count)) { > -#ifdef CONFIG_X86 > - if (shmem->map_wc) > - set_pages_array_wb(shmem->pages, obj->size >> PAGE_SHIFT); > -#endif > - > - drm_gem_put_pages(obj, shmem->pages, > - shmem->pages_mark_dirty_on_put, > - shmem->pages_mark_accessed_on_put); > - shmem->pages = NULL; > - } > + if (refcount_dec_and_test(&shmem->pages_use_count)) > + drm_gem_shmem_free_pages(shmem); > } > EXPORT_SYMBOL_GPL(drm_gem_shmem_put_pages_locked); >
diff --git a/drivers/gpu/drm/drm_gem_shmem_helper.c b/drivers/gpu/drm/drm_gem_shmem_helper.c index 3403700780c3..799a3c5015ad 100644 --- a/drivers/gpu/drm/drm_gem_shmem_helper.c +++ b/drivers/gpu/drm/drm_gem_shmem_helper.c @@ -128,6 +128,22 @@ struct drm_gem_shmem_object *drm_gem_shmem_create(struct drm_device *dev, size_t } EXPORT_SYMBOL_GPL(drm_gem_shmem_create); +static void +drm_gem_shmem_free_pages(struct drm_gem_shmem_object *shmem) +{ + struct drm_gem_object *obj = &shmem->base; + +#ifdef CONFIG_X86 + if (shmem->map_wc) + set_pages_array_wb(shmem->pages, obj->size >> PAGE_SHIFT); +#endif + + drm_gem_put_pages(obj, shmem->pages, + shmem->pages_mark_dirty_on_put, + shmem->pages_mark_accessed_on_put); + shmem->pages = NULL; +} + /** * drm_gem_shmem_free - Free resources associated with a shmem GEM object * @shmem: shmem GEM object to free @@ -142,8 +158,6 @@ void drm_gem_shmem_free(struct drm_gem_shmem_object *shmem) if (obj->import_attach) { drm_prime_gem_destroy(obj, shmem->sgt); } else { - dma_resv_lock(shmem->base.resv, NULL); - drm_WARN_ON(obj->dev, refcount_read(&shmem->vmap_use_count)); if (shmem->sgt) { @@ -152,13 +166,12 @@ void drm_gem_shmem_free(struct drm_gem_shmem_object *shmem) sg_free_table(shmem->sgt); kfree(shmem->sgt); } - if (shmem->pages) - drm_gem_shmem_put_pages_locked(shmem); + if (shmem->pages && + refcount_dec_and_test(&shmem->pages_use_count)) + drm_gem_shmem_free_pages(shmem); drm_WARN_ON(obj->dev, refcount_read(&shmem->pages_use_count)); drm_WARN_ON(obj->dev, refcount_read(&shmem->pages_pin_count)); - - dma_resv_unlock(shmem->base.resv); } drm_gem_object_release(obj); @@ -208,21 +221,10 @@ static int drm_gem_shmem_get_pages_locked(struct drm_gem_shmem_object *shmem) */ void drm_gem_shmem_put_pages_locked(struct drm_gem_shmem_object *shmem) { - struct drm_gem_object *obj = &shmem->base; - dma_resv_assert_held(shmem->base.resv); - if (refcount_dec_and_test(&shmem->pages_use_count)) { -#ifdef CONFIG_X86 - if (shmem->map_wc) - set_pages_array_wb(shmem->pages, obj->size >> PAGE_SHIFT); -#endif - - drm_gem_put_pages(obj, shmem->pages, - shmem->pages_mark_dirty_on_put, - shmem->pages_mark_accessed_on_put); - shmem->pages = NULL; - } + if (refcount_dec_and_test(&shmem->pages_use_count)) + drm_gem_shmem_free_pages(shmem); } EXPORT_SYMBOL_GPL(drm_gem_shmem_put_pages_locked);
Prepare drm_gem_shmem_free() to addition of memory shrinker support to drm-shmem by adding and using variant of put_pages() that doesn't touch reservation lock. Reservation shouldn't be touched because lockdep will trigger a bogus warning about locking contention with fs_reclaim code paths that can't happen during the time when GEM is freed and lockdep doesn't know about that. Signed-off-by: Dmitry Osipenko <dmitry.osipenko@collabora.com> --- drivers/gpu/drm/drm_gem_shmem_helper.c | 40 ++++++++++++++------------ 1 file changed, 21 insertions(+), 19 deletions(-)