This is a note to let you know that I've just added the patch titled
drm/ttm: add ttm_bo_pin()/ttm_bo_unpin() v2
to the 5.10-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
drm-ttm-add-ttm_bo_pin-ttm_bo_unpin-v2.patch
and it can be found in the queue-5.10 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit ce04a98537b093ba8b1759c732d9b359f783ee7f
Author: Christian König <christian.koenig@xxxxxxx>
Date: Mon Sep 21 13:05:54 2020 +0200
drm/ttm: add ttm_bo_pin()/ttm_bo_unpin() v2
[ Upstream commit deb0814b43f370a448a498409d949e38c9d8f02e ]
As an alternative to the placement flag add a
pin count to the ttm buffer object.
v2: add dma_resv_assert_help() calls
Signed-off-by: Christian König <christian.koenig@xxxxxxx>
Reviewed-by: Dave Airlie <airlied@xxxxxxxxxx>
Reviewed-by: Huang Rui <ray.huang@xxxxxxx>
Link: https://patchwork.freedesktop.org/patch/391596/?series=81973&rev=1
Stable-dep-of: a2848d08742c ("drm/ttm: never consider pinned BOs for eviction&swap")
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/drivers/gpu/drm/ttm/ttm_bo.c b/drivers/gpu/drm/ttm/ttm_bo.c
index f673292eec9db..9a05caec3c996 100644
--- a/drivers/gpu/drm/ttm/ttm_bo.c
+++ b/drivers/gpu/drm/ttm/ttm_bo.c
@@ -115,7 +115,7 @@ static void ttm_bo_add_mem_to_lru(struct ttm_buffer_object *bo,
struct ttm_bo_device *bdev = bo->bdev;
struct ttm_resource_manager *man;
- if (!list_empty(&bo->lru))
+ if (!list_empty(&bo->lru) || bo->pin_count)
return;
if (mem->placement & TTM_PL_FLAG_NO_EVICT)
@@ -165,7 +165,8 @@ void ttm_bo_move_to_lru_tail(struct ttm_buffer_object *bo,
ttm_bo_del_from_lru(bo);
ttm_bo_add_mem_to_lru(bo, &bo->mem);
- if (bulk && !(bo->mem.placement & TTM_PL_FLAG_NO_EVICT)) {
+ if (bulk && !(bo->mem.placement & TTM_PL_FLAG_NO_EVICT) &&
+ !bo->pin_count) {
switch (bo->mem.mem_type) {
case TTM_PL_TT:
ttm_bo_bulk_move_set_pos(&bulk->tt[bo->priority], bo);
@@ -544,8 +545,9 @@ static void ttm_bo_release(struct kref *kref)
* shrinkers, now that they are queued for
* destruction.
*/
- if (bo->mem.placement & TTM_PL_FLAG_NO_EVICT) {
+ if (bo->mem.placement & TTM_PL_FLAG_NO_EVICT || bo->pin_count) {
bo->mem.placement &= ~TTM_PL_FLAG_NO_EVICT;
+ bo->pin_count = 0;
ttm_bo_del_from_lru(bo);
ttm_bo_add_mem_to_lru(bo, &bo->mem);
}
@@ -1174,6 +1176,7 @@ int ttm_bo_init_reserved(struct ttm_bo_device *bdev,
bo->moving = NULL;
bo->mem.placement = TTM_PL_FLAG_CACHED;
bo->acc_size = acc_size;
+ bo->pin_count = 0;
bo->sg = sg;
if (resv) {
bo->base.resv = resv;
diff --git a/drivers/gpu/drm/ttm/ttm_bo_util.c b/drivers/gpu/drm/ttm/ttm_bo_util.c
index fb2a25f8408fc..1968df9743fcb 100644
--- a/drivers/gpu/drm/ttm/ttm_bo_util.c
+++ b/drivers/gpu/drm/ttm/ttm_bo_util.c
@@ -352,7 +352,6 @@ static int ttm_buffer_object_transfer(struct ttm_buffer_object *bo,
return -ENOMEM;
fbo->base = *bo;
- fbo->base.mem.placement |= TTM_PL_FLAG_NO_EVICT;
ttm_bo_get(bo);
fbo->bo = bo;
@@ -372,6 +371,7 @@ static int ttm_buffer_object_transfer(struct ttm_buffer_object *bo,
kref_init(&fbo->base.kref);
fbo->base.destroy = &ttm_transfered_destroy;
fbo->base.acc_size = 0;
+ fbo->base.pin_count = 1;
if (bo->type != ttm_bo_type_sg)
fbo->base.base.resv = &fbo->base.base._resv;
diff --git a/include/drm/ttm/ttm_bo_api.h b/include/drm/ttm/ttm_bo_api.h
index 0f7cd21d6d748..33aca60870e26 100644
--- a/include/drm/ttm/ttm_bo_api.h
+++ b/include/drm/ttm/ttm_bo_api.h
@@ -157,6 +157,7 @@ struct ttm_buffer_object {
struct dma_fence *moving;
unsigned priority;
+ unsigned pin_count;
/**
* Special members that are protected by the reserve lock
@@ -606,6 +607,31 @@ static inline bool ttm_bo_uses_embedded_gem_object(struct ttm_buffer_object *bo)
return bo->base.dev != NULL;
}
+/**
+ * ttm_bo_pin - Pin the buffer object.
+ * @bo: The buffer object to pin
+ *
+ * Make sure the buffer is not evicted any more during memory pressure.
+ */
+static inline void ttm_bo_pin(struct ttm_buffer_object *bo)
+{
+ dma_resv_assert_held(bo->base.resv);
+ ++bo->pin_count;
+}
+
+/**
+ * ttm_bo_unpin - Unpin the buffer object.
+ * @bo: The buffer object to unpin
+ *
+ * Allows the buffer object to be evicted again during memory pressure.
+ */
+static inline void ttm_bo_unpin(struct ttm_buffer_object *bo)
+{
+ dma_resv_assert_held(bo->base.resv);
+ WARN_ON_ONCE(!bo->pin_count);
+ --bo->pin_count;
+}
+
int ttm_mem_evict_first(struct ttm_bo_device *bdev,
struct ttm_resource_manager *man,
const struct ttm_place *place,
