From: Paolo Abeni Date: Tue, 19 Sep 2017 10:11:43 +0000 (+0200) Subject: udp: do rmem bulk free even if the rx sk queue is empty X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=0d4a6608f68c7532dcbfec2ea1150c9761767d03;p=linux.git udp: do rmem bulk free even if the rx sk queue is empty The commit 6b229cf77d68 ("udp: add batching to udp_rmem_release()") reduced greatly the cacheline contention between the BH and the US reader batching the rmem updates in most scenarios. Such optimization is explicitly avoided if the US reader is faster then BH processing. My fault, I initially suggested this kind of behavior due to concerns of possible regressions with small sk_rcvbuf values. Tests showed such concerns are misplaced, so this commit relaxes the condition for rmem bulk updates, obtaining small but measurable performance gain in the scenario described above. Signed-off-by: Paolo Abeni Signed-off-by: David S. Miller --- diff --git a/net/ipv4/udp.c b/net/ipv4/udp.c index ef29df8648e4d..784ced0b91501 100644 --- a/net/ipv4/udp.c +++ b/net/ipv4/udp.c @@ -1212,8 +1212,7 @@ static void udp_rmem_release(struct sock *sk, int size, int partial, if (likely(partial)) { up->forward_deficit += size; size = up->forward_deficit; - if (size < (sk->sk_rcvbuf >> 2) && - !skb_queue_empty(&up->reader_queue)) + if (size < (sk->sk_rcvbuf >> 2)) return; } else { size += up->forward_deficit;