Re: [PATCN net-next] net_sched: gen_estimator: complete rewrite of rate estimators
From: Eric Dumazet <hidden>
Date: 2016-12-04 07:12:27
Also in:
netfilter-devel
On Sat, 2016-12-03 at 23:07 -0800, Eric Dumazet wrote:
From: Eric Dumazet <edumazet@google.com> 1) Old code was hard to maintain, due to complex lock chains. (We probably will be able to remove some kfree_rcu() in callers) 2) Using a single timer to update all estimators does not scale. 3) Code was buggy on 32bit kernel (WRITE_ONCE() on 64bit quantity is not supposed to work well)
quoted hunk ↗ jump to hunk
diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c index c7adcb57654ea57d1ba6702c91743cb7d2c74d28..859b60bfa86712031186fffc09c65bc43aa065dd 100644 --- a/net/ipv4/tcp_output.c +++ b/net/ipv4/tcp_output.c@@ -2081,6 +2081,14 @@ static bool tcp_small_queue_check(struct sock *sk, const struct sk_buff *skb, limit <<= factor; if (atomic_read(&sk->sk_wmem_alloc) > limit) { + /* Special case where TX completion is delayed too much : + * If the skb we try to send is the first skb in write queue, + * then send it ! + * No need to wait for TX completion to call us back. + */ + if (skb == sk->sk_write_queue.next) + return false; +
Oups, this has nothing to do here. I will send a v2, sorry.