net: page_pool: split the page_pool_params into fast and slow

struct page_pool is rather performance critical and we use 16B of the first cache line to store 2 pointers used only by test code. Future patches will add more informational (non-fast path) attributes. It's convenient for the user of the API to not have to worry which fields are fast and which are slow path. Use struct groups to split the params into the two categories internally. Acked-by: Jesper Dangaard Brouer <[email protected]> Reviewed-by: Mina Almasry <[email protected]> Reviewed-by: Ilias Apalodimas <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Jakub Kicinski <[email protected]>
michalQb · Nov 22, 2023 · 5027ec1 · 5027ec1
1 parent 3a17ea7
commit 5027ec1
Show file tree

Hide file tree

Showing 2 changed files with 23 additions and 15 deletions.
diff --git a/include/net/page_pool/types.h b/include/net/page_pool/types.h
@@ -54,18 +54,22 @@ struct pp_alloc_cache {
  * @offset: DMA sync address offset for PP_FLAG_DMA_SYNC_DEV
  */
 struct page_pool_params {
- unsigned int flags;
- unsigned int order;
- unsigned int pool_size;
- int nid;
- struct device *dev;
- struct napi_struct *napi;
- enum dma_data_direction dma_dir;
- unsigned int max_len;
- unsigned int offset;
+ struct_group_tagged(page_pool_params_fast, fast,
+ unsigned int flags;
+ unsigned int order;
+ unsigned int pool_size;
+ int nid;
+ struct device *dev;
+ struct napi_struct *napi;
+ enum dma_data_direction dma_dir;
+ unsigned int max_len;
+ unsigned int offset;
+ );
+ struct_group_tagged(page_pool_params_slow, slow,
 /* private: used by test code only */
- void (*init_callback)(struct page *page, void *arg);
- void *init_arg;
+ void (*init_callback)(struct page *page, void *arg);
+ void *init_arg;
+ );
 };
 
 #ifdef CONFIG_PAGE_POOL_STATS
@@ -119,7 +123,7 @@ struct page_pool_stats {
 #endif
 
 struct page_pool {
- struct page_pool_params p;
+ struct page_pool_params_fast p;
 
  long frag_users;
  struct page *frag_page;
@@ -178,6 +182,9 @@ struct page_pool {
  refcount_t user_cnt;
 
  u64 destroy_cnt;
+
+ /* Slow/Control-path information follows */
+ struct page_pool_params_slow slow;
 };
 
 struct page *page_pool_alloc_pages(struct page_pool *pool, gfp_t gfp);

diff --git a/net/core/page_pool.c b/net/core/page_pool.c
@@ -173,7 +173,8 @@ static int page_pool_init(struct page_pool *pool,
 {
  unsigned int ring_qsize = 1024; /* Default */
 
- memcpy(&pool->p, params, sizeof(pool->p));
+ memcpy(&pool->p, &params->fast, sizeof(pool->p));
+ memcpy(&pool->slow, &params->slow, sizeof(pool->slow));
 
  /* Validate only known flags were used */
  if (pool->p.flags & ~(PP_FLAG_ALL))
@@ -388,8 +389,8 @@ static void page_pool_set_pp_info(struct page_pool *pool,
  * the overhead is negligible.
  */
  page_pool_fragment_page(page, 1);
- if (pool->p.init_callback)
- pool->p.init_callback(page, pool->p.init_arg);
+ if (pool->slow.init_callback)
+ pool->slow.init_callback(page, pool->slow.init_arg);
 }
 
 static void page_pool_clear_pp_info(struct page *page)