netdev - [PATCH v2 07/24] page_pool: Convert __page_pool_put_page() to __page_pool_put

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Message-Id: <20230105214631.3939268-8-willy@infradead.org>
Date:   Thu,  5 Jan 2023 21:46:14 +0000
From:   "Matthew Wilcox (Oracle)" <willy@...radead.org>
To:     Jesper Dangaard Brouer <hawk@...nel.org>,
        Ilias Apalodimas <ilias.apalodimas@...aro.org>
Cc:     "Matthew Wilcox (Oracle)" <willy@...radead.org>,
        netdev@...r.kernel.org, linux-mm@...ck.org,
        Shakeel Butt <shakeelb@...gle.com>
Subject: [PATCH v2 07/24] page_pool: Convert __page_pool_put_page() to __page_pool_put_netmem()

Removes the call to compound_head() hidden in put_page() which
saves 169 bytes of kernel text as __page_pool_put_page() is
inlined twice.

Signed-off-by: Matthew Wilcox (Oracle) <willy@...radead.org>
---
 net/core/page_pool.c | 29 +++++++++++++++++++----------
 1 file changed, 19 insertions(+), 10 deletions(-)

diff --git a/net/core/page_pool.c b/net/core/page_pool.c
index b606952773a6..8f3f7cc5a2d5 100644
--- a/net/core/page_pool.c
+++ b/net/core/page_pool.c
@@ -558,8 +558,8 @@ static bool page_pool_recycle_in_cache(struct page *page,
  * If the page refcnt != 1, then the page will be returned to memory
  * subsystem.
  */
-static __always_inline struct page *
-__page_pool_put_page(struct page_pool *pool, struct page *page,
+static __always_inline struct netmem *
+__page_pool_put_netmem(struct page_pool *pool, struct netmem *nmem,
 		     unsigned int dma_sync_size, bool allow_direct)
 {
 	/* This allocator is optimized for the XDP mode that uses
@@ -571,19 +571,20 @@ __page_pool_put_page(struct page_pool *pool, struct page *page,
 	 * page is NOT reusable when allocated when system is under
 	 * some pressure. (page_is_pfmemalloc)
 	 */
-	if (likely(page_ref_count(page) == 1 && !page_is_pfmemalloc(page))) {
-		/* Read barrier done in page_ref_count / READ_ONCE */
+	if (likely(netmem_ref_count(nmem) == 1 &&
+		   !netmem_is_pfmemalloc(nmem))) {
+		/* Read barrier done in netmem_ref_count / READ_ONCE */
 
 		if (pool->p.flags & PP_FLAG_DMA_SYNC_DEV)
-			page_pool_dma_sync_for_device(pool, page,
+			page_pool_dma_sync_for_device(pool, netmem_page(nmem),
 						      dma_sync_size);
 
 		if (allow_direct && in_serving_softirq() &&
-		    page_pool_recycle_in_cache(page, pool))
+		    page_pool_recycle_in_cache(netmem_page(nmem), pool))
 			return NULL;
 
 		/* Page found as candidate for recycling */
-		return page;
+		return nmem;
 	}
 	/* Fallback/non-XDP mode: API user have elevated refcnt.
 	 *
@@ -599,13 +600,21 @@ __page_pool_put_page(struct page_pool *pool, struct page *page,
 	 * will be invoking put_page.
 	 */
 	recycle_stat_inc(pool, released_refcnt);
-	/* Do not replace this with page_pool_return_page() */
-	page_pool_release_page(pool, page);
-	put_page(page);
+	/* Do not replace this with page_pool_return_netmem() */
+	page_pool_release_netmem(pool, nmem);
+	netmem_put(nmem);
 
 	return NULL;
 }
 
+static __always_inline struct page *
+__page_pool_put_page(struct page_pool *pool, struct page *page,
+		     unsigned int dma_sync_size, bool allow_direct)
+{
+	return netmem_page(__page_pool_put_netmem(pool, page_netmem(page),
+						dma_sync_size, allow_direct));
+}
+
 void page_pool_put_defragged_page(struct page_pool *pool, struct page *page,
 				  unsigned int dma_sync_size, bool allow_direct)
 {
-- 
2.35.1