netdev - [PATCH net-next] net: Don't return pfmemalloc pages to the page pool.

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Date:   Wed, 19 Dec 2018 12:06:51 -0800
From:   Jonathan Lemon <jonathan.lemon@...il.com>
To:     <netdev@...r.kernel.org>
CC:     <brouer@...hat.com>, Jonathan Lemon <jonathan.lemon@...il.com>
Subject: [PATCH net-next] net: Don't return pfmemalloc pages to the page pool.

Return pfmemalloc pages back to the page allocator, instead of holding them
in the page pool.  While here, also use the __page_pool_return_page() API.

Signed-off-by: Jonathan Lemon <jonathan.lemon@...il.com>
---
 net/core/page_pool.c | 5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/net/core/page_pool.c b/net/core/page_pool.c
index 43a932cb609b..091007ff14a3 100644
--- a/net/core/page_pool.c
+++ b/net/core/page_pool.c
@@ -233,7 +233,7 @@ void __page_pool_put_page(struct page_pool *pool,
 	 *
 	 * refcnt == 1 means page_pool owns page, and can recycle it.
 	 */
-	if (likely(page_ref_count(page) == 1)) {
+	if (likely(page_ref_count(page) == 1 && !page_is_pfmemalloc(page))) {
 		/* Read barrier done in page_ref_count / READ_ONCE */

 		if (allow_direct && in_serving_softirq())
@@ -259,8 +259,7 @@ void __page_pool_put_page(struct page_pool *pool,
 	 * doing refcnt based recycle tricks, meaning another process
 	 * will be invoking put_page.
 	 */
-	__page_pool_clean_page(pool, page);
-	put_page(page);
+	__page_pool_return_page(pool, page);
 }
 EXPORT_SYMBOL(__page_pool_put_page);

-- 
2.17.1