dccp_init() is never called in atomic context.
This function is only set as a parameter of module_init().

Despite never getting called from atomic context,
dccp_init() calls __get_free_pages() with GFP_ATOMIC,
which waits busily for allocation.
GFP_ATOMIC is not necessary and can be replaced with GFP_KERNEL,
to avoid busy waiting and improve the possibility of sucessful allocation.

This is found by a static analysis tool named DCNS written by myself.
And I also manually check it.

Signed-off-by: Jia-Ju Bai <baijiaju1...@gmail.com>
---
 net/dccp/proto.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/net/dccp/proto.c b/net/dccp/proto.c
index b68168f..f63ba93 100644
--- a/net/dccp/proto.c
+++ b/net/dccp/proto.c
@@ -1159,7 +1159,7 @@ static int __init dccp_init(void)
                        hash_size--;
                dccp_hashinfo.ehash_mask = hash_size - 1;
                dccp_hashinfo.ehash = (struct inet_ehash_bucket *)
-                       __get_free_pages(GFP_ATOMIC|__GFP_NOWARN, ehash_order);
+                       __get_free_pages(GFP_KERNEL|__GFP_NOWARN, ehash_order);
        } while (!dccp_hashinfo.ehash && --ehash_order > 0);
 
        if (!dccp_hashinfo.ehash) {
@@ -1182,7 +1182,7 @@ static int __init dccp_init(void)
                    bhash_order > 0)
                        continue;
                dccp_hashinfo.bhash = (struct inet_bind_hashbucket *)
-                       __get_free_pages(GFP_ATOMIC|__GFP_NOWARN, bhash_order);
+                       __get_free_pages(GFP_KERNEL|__GFP_NOWARN, bhash_order);
        } while (!dccp_hashinfo.bhash && --bhash_order >= 0);
 
        if (!dccp_hashinfo.bhash) {
-- 
1.9.1

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