netdev - [PATCH net-next 2/7] page_pool: support non-split page with PP_FLAG_PAGE

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Date:   Wed, 22 Sep 2021 17:41:26 +0800
From:   Yunsheng Lin <linyunsheng@...wei.com>
To:     <davem@...emloft.net>, <kuba@...nel.org>
CC:     <netdev@...r.kernel.org>, <linux-kernel@...r.kernel.org>,
        <linuxarm@...neuler.org>, <hawk@...nel.org>,
        <ilias.apalodimas@...aro.org>, <jonathan.lemon@...il.com>,
        <alobakin@...me>, <willemb@...gle.com>, <cong.wang@...edance.com>,
        <pabeni@...hat.com>, <haokexin@...il.com>, <nogikh@...gle.com>,
        <elver@...gle.com>, <memxor@...il.com>, <edumazet@...gle.com>,
        <alexander.duyck@...il.com>, <dsahern@...il.com>
Subject: [PATCH net-next 2/7] page_pool: support non-split page with PP_FLAG_PAGE_FRAG

Currently when PP_FLAG_PAGE_FRAG is set, the caller is not
expected to call page_pool_alloc_pages() directly because of
the PP_FLAG_PAGE_FRAG checking in __page_pool_put_page().

The patch removes the above checking to enable non-split page
support when PP_FLAG_PAGE_FRAG is set.

Reviewed-by: Alexander Duyck <alexanderduyck@...com>
Signed-off-by: Yunsheng Lin <linyunsheng@...wei.com>
---
 net/core/page_pool.c | 12 +++++++-----
 1 file changed, 7 insertions(+), 5 deletions(-)

diff --git a/net/core/page_pool.c b/net/core/page_pool.c
index a65bd7972e37..f7e71dcb6a2e 100644
--- a/net/core/page_pool.c
+++ b/net/core/page_pool.c
@@ -315,11 +315,14 @@ struct page *page_pool_alloc_pages(struct page_pool *pool, gfp_t gfp)
 
 	/* Fast-path: Get a page from cache */
 	page = __page_pool_get_cached(pool);
-	if (page)
-		return page;
 
 	/* Slow-path: cache empty, do real allocation */
-	page = __page_pool_alloc_pages_slow(pool, gfp);
+	if (!page)
+		page = __page_pool_alloc_pages_slow(pool, gfp);
+
+	if (likely(page))
+		page_pool_set_frag_count(page, 1);
+
 	return page;
 }
 EXPORT_SYMBOL(page_pool_alloc_pages);
@@ -428,8 +431,7 @@ __page_pool_put_page(struct page_pool *pool, struct page *page,
 		     unsigned int dma_sync_size, bool allow_direct)
 {
 	/* It is not the last user for the page frag case */
-	if (pool->p.flags & PP_FLAG_PAGE_FRAG &&
-	    page_pool_atomic_sub_frag_count_return(page, 1))
+	if (page_pool_atomic_sub_frag_count_return(page, 1))
 		return NULL;
 
 	/* This allocator is optimized for the XDP mode that uses
-- 
2.33.0