netdev - [PATCH net-next 0/2] inet: factorize sk_wmem

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Message-Id: <20180331201626.186789-1-edumazet@google.com>
Date:   Sat, 31 Mar 2018 13:16:24 -0700
From:   Eric Dumazet <edumazet@...gle.com>
To:     "David S . Miller" <davem@...emloft.net>
Cc:     netdev <netdev@...r.kernel.org>,
        Eric Dumazet <edumazet@...gle.com>,
        Eric Dumazet <eric.dumazet@...il.com>
Subject: [PATCH net-next 0/2] inet: factorize sk_wmem_alloc updates

While testing my inet defrag changes, I found that senders
could spend ~20% of cpu cycles in skb_set_owner_w() updating
sk->sk_wmem_alloc for every fragment they cook, competing
with TX completion of prior skbs possibly happening on another cpus.

One solution to this problem is to use alloc_skb() instead
of sock_wmalloc() and manually perform a single sk_wmem_alloc change.

This greatly increases speed for applications sending big UDP datagrams.

Eric Dumazet (2):
  ipv4: factorize sk_wmem_alloc updates done by __ip_append_data()
  ipv6: factorize sk_wmem_alloc updates done by __ip6_append_data()

 net/ipv4/ip_output.c  | 17 ++++++++++++-----
 net/ipv6/ip6_output.c | 17 ++++++++++++-----
 2 files changed, 24 insertions(+), 10 deletions(-)

-- 
2.17.0.rc1.321.gba9d0f2565-goog