Re: [Intel-gfx] [PATCH v5 2/9] drm/i915/gt: Optimize the migration and clear loop

[Thomas Hellström (Intel) <thomas_os@xxxxxxxxxxxx>]

On 3/21/22 23:44, Ramalingam C wrote:
> Move the static calculations out of the loops for copy and clear.
>
> Signed-off-by: Ramalingam C <ramalingam.c@xxxxxxxxx>

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


> ---
>   drivers/gpu/drm/i915/gt/intel_migrate.c | 44 ++++++++++++-------------
>   1 file changed, 21 insertions(+), 23 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/gt/intel_migrate.c b/drivers/gpu/drm/i915/gt/intel_migrate.c
> index 73199ebf0671..b656685a486d 100644
> --- a/drivers/gpu/drm/i915/gt/intel_migrate.c
> +++ b/drivers/gpu/drm/i915/gt/intel_migrate.c
> @@ -526,6 +526,7 @@ intel_context_migrate_copy(struct intel_context *ce,
>   			   struct i915_request **out)
>   {
>   	struct sgt_dma it_src = sg_sgt(src), it_dst = sg_sgt(dst);
> +	u32 src_offset, dst_offset;
>   	struct i915_request *rq;
>   	int err;
>   
> @@ -534,8 +535,20 @@ intel_context_migrate_copy(struct intel_context *ce,
>   
>   	GEM_BUG_ON(ce->ring->size < SZ_64K);
>   
> +	src_offset = 0;
> +	dst_offset = CHUNK_SZ;
> +	if (HAS_64K_PAGES(ce->engine->i915)) {
> +		GEM_BUG_ON(!src_is_lmem && !dst_is_lmem);
> +
> +		src_offset = 0;
> +		dst_offset = 0;
> +		if (src_is_lmem)
> +			src_offset = CHUNK_SZ;
> +		if (dst_is_lmem)
> +			dst_offset = 2 * CHUNK_SZ;
> +	}
> +
>   	do {
> -		u32 src_offset, dst_offset;
>   		int len;
>   
>   		rq = i915_request_create(ce);
> @@ -563,19 +576,6 @@ intel_context_migrate_copy(struct intel_context *ce,
>   		if (err)
>   			goto out_rq;
>   
> -		src_offset = 0;
> -		dst_offset = CHUNK_SZ;
> -		if (HAS_64K_PAGES(ce->engine->i915)) {
> -			GEM_BUG_ON(!src_is_lmem && !dst_is_lmem);
> -
> -			src_offset = 0;
> -			dst_offset = 0;
> -			if (src_is_lmem)
> -				src_offset = CHUNK_SZ;
> -			if (dst_is_lmem)
> -				dst_offset = 2 * CHUNK_SZ;
> -		}
> -
>   		len = emit_pte(rq, &it_src, src_cache_level, src_is_lmem,
>   			       src_offset, CHUNK_SZ);
>   		if (len <= 0) {
> @@ -585,12 +585,10 @@ intel_context_migrate_copy(struct intel_context *ce,
>   
>   		err = emit_pte(rq, &it_dst, dst_cache_level, dst_is_lmem,
>   			       dst_offset, len);
> -		if (err < 0)
> -			goto out_rq;
> -		if (err < len) {
> +		if (err < len)
>   			err = -EINVAL;
> +		if (err < 0)
>   			goto out_rq;
> -		}
>   
>   		err = rq->engine->emit_flush(rq, EMIT_INVALIDATE);
>   		if (err)
> @@ -694,6 +692,7 @@ intel_context_migrate_clear(struct intel_context *ce,
>   {
>   	struct sgt_dma it = sg_sgt(sg);
>   	struct i915_request *rq;
> +	u32 offset;
>   	int err;
>   
>   	GEM_BUG_ON(ce->vm != ce->engine->gt->migrate.context->vm);
> @@ -701,8 +700,11 @@ intel_context_migrate_clear(struct intel_context *ce,
>   
>   	GEM_BUG_ON(ce->ring->size < SZ_64K);
>   
> +	offset = 0;
> +	if (HAS_64K_PAGES(ce->engine->i915) && is_lmem)
> +		offset = CHUNK_SZ;
> +
>   	do {
> -		u32 offset;
>   		int len;
>   
>   		rq = i915_request_create(ce);
> @@ -730,10 +732,6 @@ intel_context_migrate_clear(struct intel_context *ce,
>   		if (err)
>   			goto out_rq;
>   
> -		offset = 0;
> -		if (HAS_64K_PAGES(ce->engine->i915) && is_lmem)
> -			offset = CHUNK_SZ;
> -
>   		len = emit_pte(rq, &it, cache_level, is_lmem, offset, CHUNK_SZ);
>   		if (len <= 0) {
>   			err = len;