[PATCH net-next 09/16] net/mlx5e: Optimize the page cache reducing its size 2x
From: Saeed Mahameed <saeed@kernel.org>
Date: 2022-09-29 07:23:09
Subsystem:
mellanox ethernet driver (mlx5e), mellanox mlx5 core vpi driver, networking drivers, the rest · Maintainers:
Saeed Mahameed, Tariq Toukan, Mark Bloch, Leon Romanovsky, Andrew Lunn, "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds
From: Maxim Mikityanskiy <redacted> RX page cache stores dma_info structs, that consist of a pointer to struct page and a DMA address. In fact, the DMA address is extracted from struct page using page_pool_get_dma_addr when a page is pushed to the cache. By moving this call to the point when a page is popped from the cache, we can avoid storing the DMA address in the cache, effectively reducing its size by two times without losing any functionality. Signed-off-by: Maxim Mikityanskiy <redacted> Reviewed-by: Saeed Mahameed <saeedm@nvidia.com> Reviewed-by: Tariq Toukan <tariqt@nvidia.com> Signed-off-by: Saeed Mahameed <saeedm@nvidia.com> --- drivers/net/ethernet/mellanox/mlx5/core/en.h | 2 +- drivers/net/ethernet/mellanox/mlx5/core/en_main.c | 4 +--- drivers/net/ethernet/mellanox/mlx5/core/en_rx.c | 8 ++++---- 3 files changed, 6 insertions(+), 8 deletions(-)
diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en.h b/drivers/net/ethernet/mellanox/mlx5/core/en.h
index 449c016262f4..6b91fa7f2221 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/en.h
+++ b/drivers/net/ethernet/mellanox/mlx5/core/en.h@@ -630,7 +630,7 @@ struct mlx5e_mpw_info { struct mlx5e_page_cache { u32 head; u32 tail; - struct mlx5e_dma_info page_cache[MLX5E_CACHE_SIZE]; + struct page *page_cache[MLX5E_CACHE_SIZE]; }; struct mlx5e_rq;
diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en_main.c b/drivers/net/ethernet/mellanox/mlx5/core/en_main.c
index fbbc2e792c27..b1d8fd08887b 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/en_main.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/en_main.c@@ -830,13 +830,11 @@ static void mlx5e_free_rq(struct mlx5e_rq *rq) for (i = rq->page_cache.head; i != rq->page_cache.tail; i = (i + 1) & (MLX5E_CACHE_SIZE - 1)) { - struct mlx5e_dma_info *dma_info = &rq->page_cache.page_cache[i]; - /* With AF_XDP, page_cache is not used, so this loop is not * entered, and it's safe to call mlx5e_page_release_dynamic * directly. */ - mlx5e_page_release_dynamic(rq, dma_info->page, false); + mlx5e_page_release_dynamic(rq, rq->page_cache.page_cache[i], false); } xdp_rxq_info_unreg(&rq->xdp_rxq);
diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en_rx.c b/drivers/net/ethernet/mellanox/mlx5/core/en_rx.c
index de929fde8cc6..b8aa6f843675 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/en_rx.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/en_rx.c@@ -245,8 +245,7 @@ static inline bool mlx5e_rx_cache_put(struct mlx5e_rq *rq, struct page *page) return false; } - cache->page_cache[cache->tail].page = page; - cache->page_cache[cache->tail].addr = page_pool_get_dma_addr(page); + cache->page_cache[cache->tail] = page; cache->tail = tail_next; return true; }
@@ -262,12 +261,13 @@ static inline bool mlx5e_rx_cache_get(struct mlx5e_rq *rq, return false; } - if (page_ref_count(cache->page_cache[cache->head].page) != 1) { + if (page_ref_count(cache->page_cache[cache->head]) != 1) { stats->cache_busy++; return false; } - *dma_info = cache->page_cache[cache->head]; + dma_info->page = cache->page_cache[cache->head]; + dma_info->addr = page_pool_get_dma_addr(dma_info->page); cache->head = (cache->head + 1) & (MLX5E_CACHE_SIZE - 1); stats->cache_reuse++;
--
2.37.3