| Message ID | 20230722234746.205949-2-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, 23 Jul 2023 02:47:35 +0300 Dmitry Osipenko <dmitry.osipenko@collabora.com> wrote: > Factor out pages allocation from drm_gem_shmem_get_pages() into > drm_gem_shmem_acquire_pages() function and similar for the put_pages() > in a preparation for addition of shrinker support to drm-shmem. > > Once shrinker will be added, the pages_use_count>0 will no longer determine > whether pages are pinned because pages could be swapped out by the shrinker > and then pages_use_count will be greater than 0 in this case. We will add > new pages_pin_count in a later patch. > > The new common drm_gem_shmem_acquire/release_pages() will be used by > shrinker code for performing the page swapping. > > Signed-off-by: Dmitry Osipenko <dmitry.osipenko@collabora.com> > --- > drivers/gpu/drm/drm_gem_shmem_helper.c | 65 ++++++++++++++++++++------ > 1 file changed, 52 insertions(+), 13 deletions(-) > > diff --git a/drivers/gpu/drm/drm_gem_shmem_helper.c b/drivers/gpu/drm/drm_gem_shmem_helper.c > index a783d2245599..267153853e2c 100644 > --- a/drivers/gpu/drm/drm_gem_shmem_helper.c > +++ b/drivers/gpu/drm/drm_gem_shmem_helper.c > @@ -165,21 +165,26 @@ void drm_gem_shmem_free(struct drm_gem_shmem_object *shmem) > } > EXPORT_SYMBOL_GPL(drm_gem_shmem_free); > > -static int drm_gem_shmem_get_pages(struct drm_gem_shmem_object *shmem) > +static int > +drm_gem_shmem_acquire_pages(struct drm_gem_shmem_object *shmem) > { > struct drm_gem_object *obj = &shmem->base; > struct page **pages; > > dma_resv_assert_held(shmem->base.resv); Not directly related to this patch, but can we start using _locked suffixes for any function that's expecting the dma-resv lock to be held? > > - if (shmem->pages_use_count++ > 0) > - return 0; > + if (shmem->madv < 0) { > + drm_WARN_ON(obj->dev, shmem->pages); > + return -ENOMEM; > + } > + > + if (drm_WARN_ON(obj->dev, !shmem->pages_use_count)) > + return -EINVAL; > > pages = drm_gem_get_pages(obj); > if (IS_ERR(pages)) { > drm_dbg_kms(obj->dev, "Failed to get pages (%ld)\n", > PTR_ERR(pages)); > - shmem->pages_use_count = 0; > return PTR_ERR(pages); > } > > @@ -198,6 +203,48 @@ static int drm_gem_shmem_get_pages(struct drm_gem_shmem_object *shmem) > return 0; > } > > +static int drm_gem_shmem_get_pages(struct drm_gem_shmem_object *shmem) > +{ > + int err; > + > + dma_resv_assert_held(shmem->base.resv); > + > + if (shmem->madv < 0) > + return -ENOMEM; > + > + if (shmem->pages_use_count++ > 0) > + return 0; > + > + err = drm_gem_shmem_acquire_pages(shmem); > + if (err) > + goto err_zero_use; > + > + return 0; > + > +err_zero_use: > + shmem->pages_use_count = 0; > + > + return err; > +} > + > +static void > +drm_gem_shmem_release_pages(struct drm_gem_shmem_object *shmem) > +{ > + struct drm_gem_object *obj = &shmem->base; > + > + dma_resv_assert_held(shmem->base.resv); > + > +#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_put_pages - Decrease use count on the backing pages for a shmem GEM object > * @shmem: shmem GEM object > @@ -216,15 +263,7 @@ void drm_gem_shmem_put_pages(struct drm_gem_shmem_object *shmem) > if (--shmem->pages_use_count > 0) > return; > > -#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_release_pages(shmem); > } > EXPORT_SYMBOL(drm_gem_shmem_put_pages); >
diff --git a/drivers/gpu/drm/drm_gem_shmem_helper.c b/drivers/gpu/drm/drm_gem_shmem_helper.c index a783d2245599..267153853e2c 100644 --- a/drivers/gpu/drm/drm_gem_shmem_helper.c +++ b/drivers/gpu/drm/drm_gem_shmem_helper.c @@ -165,21 +165,26 @@ void drm_gem_shmem_free(struct drm_gem_shmem_object *shmem) } EXPORT_SYMBOL_GPL(drm_gem_shmem_free); -static int drm_gem_shmem_get_pages(struct drm_gem_shmem_object *shmem) +static int +drm_gem_shmem_acquire_pages(struct drm_gem_shmem_object *shmem) { struct drm_gem_object *obj = &shmem->base; struct page **pages; dma_resv_assert_held(shmem->base.resv); - if (shmem->pages_use_count++ > 0) - return 0; + if (shmem->madv < 0) { + drm_WARN_ON(obj->dev, shmem->pages); + return -ENOMEM; + } + + if (drm_WARN_ON(obj->dev, !shmem->pages_use_count)) + return -EINVAL; pages = drm_gem_get_pages(obj); if (IS_ERR(pages)) { drm_dbg_kms(obj->dev, "Failed to get pages (%ld)\n", PTR_ERR(pages)); - shmem->pages_use_count = 0; return PTR_ERR(pages); } @@ -198,6 +203,48 @@ static int drm_gem_shmem_get_pages(struct drm_gem_shmem_object *shmem) return 0; } +static int drm_gem_shmem_get_pages(struct drm_gem_shmem_object *shmem) +{ + int err; + + dma_resv_assert_held(shmem->base.resv); + + if (shmem->madv < 0) + return -ENOMEM; + + if (shmem->pages_use_count++ > 0) + return 0; + + err = drm_gem_shmem_acquire_pages(shmem); + if (err) + goto err_zero_use; + + return 0; + +err_zero_use: + shmem->pages_use_count = 0; + + return err; +} + +static void +drm_gem_shmem_release_pages(struct drm_gem_shmem_object *shmem) +{ + struct drm_gem_object *obj = &shmem->base; + + dma_resv_assert_held(shmem->base.resv); + +#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_put_pages - Decrease use count on the backing pages for a shmem GEM object * @shmem: shmem GEM object @@ -216,15 +263,7 @@ void drm_gem_shmem_put_pages(struct drm_gem_shmem_object *shmem) if (--shmem->pages_use_count > 0) return; -#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_release_pages(shmem); } EXPORT_SYMBOL(drm_gem_shmem_put_pages);
Factor out pages allocation from drm_gem_shmem_get_pages() into drm_gem_shmem_acquire_pages() function and similar for the put_pages() in a preparation for addition of shrinker support to drm-shmem. Once shrinker will be added, the pages_use_count>0 will no longer determine whether pages are pinned because pages could be swapped out by the shrinker and then pages_use_count will be greater than 0 in this case. We will add new pages_pin_count in a later patch. The new common drm_gem_shmem_acquire/release_pages() will be used by shrinker code for performing the page swapping. Signed-off-by: Dmitry Osipenko <dmitry.osipenko@collabora.com> --- drivers/gpu/drm/drm_gem_shmem_helper.c | 65 ++++++++++++++++++++------ 1 file changed, 52 insertions(+), 13 deletions(-)