Re: [PATCH 04/10] drm/ttm: grab BO reference before locking it

[Thomas Hellström]

On Fri, 2026-07-03 at 18:31 +0200, Natalie Vock wrote:
> From: Christian König <christian.koenig@xxxxxxx>
> 
> Previously we always grabbed the BO reference after taking the lock,
> but
> that isn't necessary any more.
> 
> So avoid doing that and cleanup the handling here.
> 
> Signed-off-by: Christian König <christian.koenig@xxxxxxx>
> Signed-off-by: Natalie Vock <natalie.vock@xxxxxx>

Reviewed-by: Thomas Hellström <thomas.hellstrom@xxxxxxxxxxxxxxx>

> ---
>  drivers/gpu/drm/ttm/ttm_bo_util.c | 15 +++++++++------
>  1 file changed, 9 insertions(+), 6 deletions(-)
> 
> diff --git a/drivers/gpu/drm/ttm/ttm_bo_util.c
> b/drivers/gpu/drm/ttm/ttm_bo_util.c
> index 29f068944a972..a53b25e8c2967 100644
> --- a/drivers/gpu/drm/ttm/ttm_bo_util.c
> +++ b/drivers/gpu/drm/ttm/ttm_bo_util.c
> @@ -1010,14 +1010,17 @@ __ttm_bo_lru_cursor_next(struct
> ttm_bo_lru_cursor *curs)
>  			break;
>  
>  		bo = res->bo;
> -		if (ttm_lru_walk_trylock(curs, bo))
> -			bo_locked = true;
> -		else if (!arg->ticket || arg->ctx->no_wait_gpu ||
> arg->trylock_only)
> +		if (!ttm_bo_get_unless_zero(bo))
>  			continue;
>  
> -		if (!ttm_bo_get_unless_zero(bo)) {
> -			if (curs->needs_unlock)
> -				dma_resv_unlock(bo->base.resv);
> +		if (ttm_lru_walk_trylock(curs, bo)) {
> +			bo_locked = true;
> +
> +		} else if (!arg->ticket || arg->ctx->no_wait_gpu ||
> +			   arg->trylock_only) {
> +			spin_unlock(lru_lock);
> +			ttm_bo_put(bo);
> +			spin_lock(lru_lock);
>  			continue;
>  		}
>