linux-kernel - [PATCH v1 3/3] net: simplify sk_page

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Message-Id: <79b1009812b753c3a82d09271c4d655d644d37a6.1669036433.git.bcodding@redhat.com>
Date:   Mon, 21 Nov 2022 08:35:19 -0500
From:   Benjamin Coddington <bcodding@...hat.com>
To:     netdev@...r.kernel.org
Cc:     linux-kernel@...r.kernel.org,
        "David S. Miller" <davem@...emloft.net>,
        Eric Dumazet <edumazet@...gle.com>,
        Jakub Kicinski <kuba@...nel.org>,
        Paolo Abeni <pabeni@...hat.com>
Subject: [PATCH v1 3/3] net: simplify sk_page_frag

Now that in-kernel socket users that may recurse during reclaim have benn
converted to sk_use_task_frag = false, we can have sk_page_frag() simply
check that value.

Signed-off-by: Benjamin Coddington <bcodding@...hat.com>
---
 include/net/sock.h | 9 ++-------
 1 file changed, 2 insertions(+), 7 deletions(-)

diff --git a/include/net/sock.h b/include/net/sock.h
index ffba9e95470d..fac24c6ee30d 100644
--- a/include/net/sock.h
+++ b/include/net/sock.h
@@ -2539,19 +2539,14 @@ static inline void sk_stream_moderate_sndbuf(struct sock *sk)
  * Both direct reclaim and page faults can nest inside other
  * socket operations and end up recursing into sk_page_frag()
  * while it's already in use: explicitly avoid task page_frag
- * usage if the caller is potentially doing any of them.
- * This assumes that page fault handlers use the GFP_NOFS flags or
- * explicitly disable sk_use_task_frag.
+ * when users disable sk_use_task_frag.
  *
  * Return: a per task page_frag if context allows that,
  * otherwise a per socket one.
  */
 static inline struct page_frag *sk_page_frag(struct sock *sk)
 {
-	if (sk->sk_use_task_frag &&
-	    (sk->sk_allocation & (__GFP_DIRECT_RECLAIM | __GFP_MEMALLOC |
-				  __GFP_FS)) ==
-	    (__GFP_DIRECT_RECLAIM | __GFP_FS))
+	if (sk->sk_use_task_frag)
 		return &current->task_frag;
 
 	return &sk->sk_frag;
-- 
2.31.1