From 707f908e31d7e2c3b24fe8cafa773f67e44fc5ef Mon Sep 17 00:00:00 2001
From: Maxim Mikityanskiy <maximmi@nvidia.com>
Date: Thu, 29 Sep 2022 00:21:49 -0700
Subject: [PATCH] net/mlx5e: Optimize the page cache reducing its size 2x
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 <maximmi@nvidia.com>
Reviewed-by: Saeed Mahameed <saeedm@nvidia.com>
Reviewed-by: Tariq Toukan <tariqt@nvidia.com>
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
---
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 449c016262f4f..6b91fa7f2221f 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 fbbc2e792c279..b1d8fd08887bb 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 de929fde8cc62..b8aa6f8436754 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++;
--
2.30.2