On Tue, Sep 22, 2020 at 09:31:58PM +0800, Christian König wrote:
> 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>
Series look good for me as well.
Reviewed-by: Huang Rui <ray.huang@xxxxxxx>
Only one comment:
We can modify the TOPDOWN offset as 21 since the NO_EVICT is removed.
#define TTM_PL_FLAG_UNCACHED (1 << 17)
#define TTM_PL_FLAG_WC (1 << 18)
#define TTM_PL_FLAG_CONTIGUOUS (1 << 19)
-#define TTM_PL_FLAG_NO_EVICT (1 << 21)
#define TTM_PL_FLAG_TOPDOWN (1 << 22)
Thanks,
Ray
> ---
> drivers/gpu/drm/ttm/ttm_bo.c | 9 ++++++---
> drivers/gpu/drm/ttm/ttm_bo_util.c | 2 +-
> include/drm/ttm/ttm_bo_api.h | 26 ++++++++++++++++++++++++++
> 3 files changed, 33 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/gpu/drm/ttm/ttm_bo.c b/drivers/gpu/drm/ttm/ttm_bo.c
> index 70b3bee27850..b82b49d43942 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);
> }
> @@ -1172,6 +1174,7 @@ 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 fb2a25f8408f..1968df9743fc 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 0f7cd21d6d74..33aca60870e2 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,
> --
> 2.17.1
>
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