[PATCH] net: cleanup gfp mask in alloc_skb_with_frags

[PATCH] net: cleanup gfp mask in alloc_skb_with_frags

[Michal Hocko]

From: Michal Hocko <mhocko@suse.com>

alloc_skb_with_frags uses __GFP_NORETRY for non-sleeping allocations
which is just a noop and a little bit confusing.

__GFP_NORETRY was added by ed98df3361f0 ("net: use __GFP_NORETRY for
high order allocations") to prevent from the OOM killer. Yet this was
not enough because fb05e7a89f50 ("net: don't wait for order-3 page
allocation") didn't want an excessive reclaim for non-costly orders
so it made it completely NOWAIT while it preserved __GFP_NORETRY in
place which is now redundant.

Drop the pointless __GFP_NORETRY because this function is used as
copy&paste source for other places.

Reviewed-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Michal Hocko <mhocko@suse.com>
---
 net/core/skbuff.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/net/core/skbuff.c b/net/core/skbuff.c
index c642304f178c..eba8dae22c25 100644
--- a/net/core/skbuff.c
+++ b/net/core/skbuff.c
@@ -5276,8 +5276,7 @@ struct sk_buff *alloc_skb_with_frags(unsigned long header_len,
 			if (npages >= 1 << order) {
 				page = alloc_pages((gfp_mask & ~__GFP_DIRECT_RECLAIM) |
 						   __GFP_COMP |
-						   __GFP_NOWARN |
-						   __GFP_NORETRY,
+						   __GFP_NOWARN,
 						   order);
 				if (page)
 					goto fill_page;
-- 
2.18.0

Re: [PATCH] net: cleanup gfp mask in alloc_skb_with_frags

[David Miller]

From: Michal Hocko <mhocko@kernel.org>
Date: Thu, 28 Jun 2018 17:53:06 +0200

> From: Michal Hocko <mhocko@suse.com>
> 
> alloc_skb_with_frags uses __GFP_NORETRY for non-sleeping allocations
> which is just a noop and a little bit confusing.
> 
> __GFP_NORETRY was added by ed98df3361f0 ("net: use __GFP_NORETRY for
> high order allocations") to prevent from the OOM killer. Yet this was
> not enough because fb05e7a89f50 ("net: don't wait for order-3 page
> allocation") didn't want an excessive reclaim for non-costly orders
> so it made it completely NOWAIT while it preserved __GFP_NORETRY in
> place which is now redundant.
> 
> Drop the pointless __GFP_NORETRY because this function is used as
> copy&paste source for other places.
> 
> Reviewed-by: Eric Dumazet <edumazet@google.com>
> Signed-off-by: Michal Hocko <mhocko@suse.com>

Applied.