Commit 5537252b authored by Chris Wilson's avatar Chris Wilson Committed by Daniel Vetter
Browse files

drm/i915: Invalidate our pages under memory pressure 



Try to flush out dirty pages into the swapcache (and from there into the
swapfile) when under memory pressure and forced to drop GEM objects from
memory. In effect, this should just allow us to discard unused pages for
memory reclaim and to start writeback earlier.

v2: Hugh Dickins warned that explicitly starting writeback from
shrink_slab was prone to deadlocks within shmemfs.

Cc: Hugh Dickins <hughd@google.com>
Signed-off-by: default avatarChris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: default avatarRobert Beckett <robert.beckett@intel.com>
Reviewed-by: default avatarRafael Barbalho <rafael.barbalho@intel.com>
Signed-off-by: default avatarDaniel Vetter <daniel.vetter@ffwll.ch>
parent b453c4db

drivers/gpu/drm/i915/i915_gem.c

+27 −11
Original line number Diff line number Diff line
@@ -63,7 +63,6 @@ static unsigned long i915_gem_shrinker_scan(struct shrinker *shrinker, 
					    struct shrink_control *sc);

static unsigned long i915_gem_purge(struct drm_i915_private *dev_priv, long target);

static unsigned long i915_gem_shrink_all(struct drm_i915_private *dev_priv);

static void i915_gem_object_truncate(struct drm_i915_gem_object *obj);



static bool cpu_cache_is_coherent(struct drm_device *dev,

				  enum i915_cache_level level)
@@ -1691,12 +1690,16 @@ i915_gem_mmap_gtt_ioctl(struct drm_device *dev, void *data, 
	return i915_gem_mmap_gtt(file, dev, args->handle, &args->offset);

}



static inline int

i915_gem_object_is_purgeable(struct drm_i915_gem_object *obj)

{

	return obj->madv == I915_MADV_DONTNEED;

}



/* Immediately discard the backing storage */

static void

i915_gem_object_truncate(struct drm_i915_gem_object *obj)

{

	struct inode *inode;



	i915_gem_object_free_mmap_offset(obj);



	if (obj->base.filp == NULL)
@@ -1707,16 +1710,28 @@ i915_gem_object_truncate(struct drm_i915_gem_object *obj) 
	 * To do this we must instruct the shmfs to drop all of its

	 * backing pages, *now*.

	 */

	inode = file_inode(obj->base.filp);

	shmem_truncate_range(inode, 0, (loff_t)-1);



	shmem_truncate_range(file_inode(obj->base.filp), 0, (loff_t)-1);

	obj->madv = __I915_MADV_PURGED;

}



static inline int

i915_gem_object_is_purgeable(struct drm_i915_gem_object *obj)

/* Try to discard unwanted pages */

static void

i915_gem_object_invalidate(struct drm_i915_gem_object *obj)

{

	return obj->madv == I915_MADV_DONTNEED;

	struct address_space *mapping;



	switch (obj->madv) {

	case I915_MADV_DONTNEED:

		i915_gem_object_truncate(obj);

	case __I915_MADV_PURGED:

		return;

	}



	if (obj->base.filp == NULL)

		return;



	mapping = file_inode(obj->base.filp)->i_mapping,

	invalidate_mapping_pages(mapping, 0, (loff_t)-1);

}



static void
@@ -1781,8 +1796,7 @@ i915_gem_object_put_pages(struct drm_i915_gem_object *obj) 
	ops->put_pages(obj);

	obj->pages = NULL;



	if (i915_gem_object_is_purgeable(obj))

		i915_gem_object_truncate(obj);

	i915_gem_object_invalidate(obj);



	return 0;

}
@@ -4266,6 +4280,8 @@ void i915_gem_free_object(struct drm_gem_object *gem_obj) 


	if (WARN_ON(obj->pages_pin_count))

		obj->pages_pin_count = 0;

	if (obj->madv != __I915_MADV_PURGED)

		obj->madv = I915_MADV_DONTNEED;

	i915_gem_object_put_pages(obj);

	i915_gem_object_free_mmap_offset(obj);

	i915_gem_object_release_stolen(obj);

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