| Message ID | 20230903170736.513347-11-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 Sun, 3 Sep 2023 20:07:26 +0300 Dmitry Osipenko <dmitry.osipenko@collabora.com> wrote: > Add separate pages_pin_count for tracking of whether drm-shmem pages are > moveable or not. With the addition of memory shrinker support to drm-shmem, > the pages_use_count will no longer determine whether pages are hard-pinned > in memory, but whether pages exist and are soft-pinned (and could be swapped > out). The pages_pin_count > 1 will hard-pin pages in memory. > > Suggested-by: Boris Brezillon <boris.brezillon@collabora.com> > 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 | 24 ++++++++++++++++-------- > include/drm/drm_gem_shmem_helper.h | 10 ++++++++++ > 2 files changed, 26 insertions(+), 8 deletions(-) > > diff --git a/drivers/gpu/drm/drm_gem_shmem_helper.c b/drivers/gpu/drm/drm_gem_shmem_helper.c > index 25e99468ced2..7e1e674e2c9f 100644 > --- a/drivers/gpu/drm/drm_gem_shmem_helper.c > +++ b/drivers/gpu/drm/drm_gem_shmem_helper.c > @@ -236,18 +236,16 @@ static int drm_gem_shmem_pin_locked(struct drm_gem_shmem_object *shmem) > > dma_resv_assert_held(shmem->base.resv); > > + if (refcount_inc_not_zero(&shmem->pages_pin_count)) > + return 0; > + > ret = drm_gem_shmem_get_pages_locked(shmem); > + if (!ret) > + refcount_set(&shmem->pages_pin_count, 1); > > return ret; > } > > -static void drm_gem_shmem_unpin_locked(struct drm_gem_shmem_object *shmem) > -{ > - dma_resv_assert_held(shmem->base.resv); > - > - drm_gem_shmem_put_pages_locked(shmem); > -} > - > /** > * drm_gem_shmem_pin - Pin backing pages for a shmem GEM object > * @shmem: shmem GEM object > @@ -265,6 +263,9 @@ int drm_gem_shmem_pin(struct drm_gem_shmem_object *shmem) > > drm_WARN_ON(obj->dev, obj->import_attach); > > + if (refcount_inc_not_zero(&shmem->pages_pin_count)) > + return 0; > + > ret = dma_resv_lock_interruptible(shmem->base.resv, NULL); > if (ret) > return ret; > @@ -288,8 +289,14 @@ void drm_gem_shmem_unpin(struct drm_gem_shmem_object *shmem) > > drm_WARN_ON(obj->dev, obj->import_attach); > > + if (refcount_dec_not_one(&shmem->pages_pin_count)) > + return; > + > dma_resv_lock(shmem->base.resv, NULL); > - drm_gem_shmem_unpin_locked(shmem); > + > + if (refcount_dec_and_test(&shmem->pages_pin_count)) > + drm_gem_shmem_put_pages_locked(shmem); > + > dma_resv_unlock(shmem->base.resv); > } > EXPORT_SYMBOL_GPL(drm_gem_shmem_unpin); > @@ -634,6 +641,7 @@ void drm_gem_shmem_print_info(const struct drm_gem_shmem_object *shmem, > if (shmem->base.import_attach) > return; > > + drm_printf_indent(p, indent, "pages_pin_count=%u\n", refcount_read(&shmem->pages_pin_count)); > drm_printf_indent(p, indent, "pages_use_count=%u\n", shmem->pages_use_count); > drm_printf_indent(p, indent, "vmap_use_count=%u\n", shmem->vmap_use_count); > drm_printf_indent(p, indent, "vaddr=%p\n", shmem->vaddr); > diff --git a/include/drm/drm_gem_shmem_helper.h b/include/drm/drm_gem_shmem_helper.h > index 808083279fd5..1cd74ae5761a 100644 > --- a/include/drm/drm_gem_shmem_helper.h > +++ b/include/drm/drm_gem_shmem_helper.h > @@ -39,6 +39,16 @@ struct drm_gem_shmem_object { > */ > unsigned int pages_use_count; > > + /** > + * @pages_pin_count: > + * > + * Reference count on the pinned pages table. > + * The pages allowed to be evicted and purged by memory > + * shrinker only when the count is zero, otherwise pages > + * are hard-pinned in memory. > + */ > + refcount_t pages_pin_count; > + > /** > * @madv: State for madvise > *
diff --git a/drivers/gpu/drm/drm_gem_shmem_helper.c b/drivers/gpu/drm/drm_gem_shmem_helper.c index 25e99468ced2..7e1e674e2c9f 100644 --- a/drivers/gpu/drm/drm_gem_shmem_helper.c +++ b/drivers/gpu/drm/drm_gem_shmem_helper.c @@ -236,18 +236,16 @@ static int drm_gem_shmem_pin_locked(struct drm_gem_shmem_object *shmem) dma_resv_assert_held(shmem->base.resv); + if (refcount_inc_not_zero(&shmem->pages_pin_count)) + return 0; + ret = drm_gem_shmem_get_pages_locked(shmem); + if (!ret) + refcount_set(&shmem->pages_pin_count, 1); return ret; } -static void drm_gem_shmem_unpin_locked(struct drm_gem_shmem_object *shmem) -{ - dma_resv_assert_held(shmem->base.resv); - - drm_gem_shmem_put_pages_locked(shmem); -} - /** * drm_gem_shmem_pin - Pin backing pages for a shmem GEM object * @shmem: shmem GEM object @@ -265,6 +263,9 @@ int drm_gem_shmem_pin(struct drm_gem_shmem_object *shmem) drm_WARN_ON(obj->dev, obj->import_attach); + if (refcount_inc_not_zero(&shmem->pages_pin_count)) + return 0; + ret = dma_resv_lock_interruptible(shmem->base.resv, NULL); if (ret) return ret; @@ -288,8 +289,14 @@ void drm_gem_shmem_unpin(struct drm_gem_shmem_object *shmem) drm_WARN_ON(obj->dev, obj->import_attach); + if (refcount_dec_not_one(&shmem->pages_pin_count)) + return; + dma_resv_lock(shmem->base.resv, NULL); - drm_gem_shmem_unpin_locked(shmem); + + if (refcount_dec_and_test(&shmem->pages_pin_count)) + drm_gem_shmem_put_pages_locked(shmem); + dma_resv_unlock(shmem->base.resv); } EXPORT_SYMBOL_GPL(drm_gem_shmem_unpin); @@ -634,6 +641,7 @@ void drm_gem_shmem_print_info(const struct drm_gem_shmem_object *shmem, if (shmem->base.import_attach) return; + drm_printf_indent(p, indent, "pages_pin_count=%u\n", refcount_read(&shmem->pages_pin_count)); drm_printf_indent(p, indent, "pages_use_count=%u\n", shmem->pages_use_count); drm_printf_indent(p, indent, "vmap_use_count=%u\n", shmem->vmap_use_count); drm_printf_indent(p, indent, "vaddr=%p\n", shmem->vaddr); diff --git a/include/drm/drm_gem_shmem_helper.h b/include/drm/drm_gem_shmem_helper.h index 808083279fd5..1cd74ae5761a 100644 --- a/include/drm/drm_gem_shmem_helper.h +++ b/include/drm/drm_gem_shmem_helper.h @@ -39,6 +39,16 @@ struct drm_gem_shmem_object { */ unsigned int pages_use_count; + /** + * @pages_pin_count: + * + * Reference count on the pinned pages table. + * The pages allowed to be evicted and purged by memory + * shrinker only when the count is zero, otherwise pages + * are hard-pinned in memory. + */ + refcount_t pages_pin_count; + /** * @madv: State for madvise *
Add separate pages_pin_count for tracking of whether drm-shmem pages are moveable or not. With the addition of memory shrinker support to drm-shmem, the pages_use_count will no longer determine whether pages are hard-pinned in memory, but whether pages exist and are soft-pinned (and could be swapped out). The pages_pin_count > 1 will hard-pin pages in memory. Suggested-by: Boris Brezillon <boris.brezillon@collabora.com> Signed-off-by: Dmitry Osipenko <dmitry.osipenko@collabora.com> --- drivers/gpu/drm/drm_gem_shmem_helper.c | 24 ++++++++++++++++-------- include/drm/drm_gem_shmem_helper.h | 10 ++++++++++ 2 files changed, 26 insertions(+), 8 deletions(-)