netdev - Re: [PATCN net-next] net_sched: gen_estimator: complete rewrite of rate estimators

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <1480835547.18162.459.camel@edumazet-glaptop3.roam.corp.google.com>
Date:   Sat, 03 Dec 2016 23:12:27 -0800
From:   Eric Dumazet <eric.dumazet@...il.com>
To:     David Miller <davem@...emloft.net>
Cc:     netdev <netdev@...r.kernel.org>, netfilter-devel@...r.kernel.org
Subject: Re: [PATCN net-next] net_sched: gen_estimator: complete rewrite of
 rate estimators

On Sat, 2016-12-03 at 23:07 -0800, Eric Dumazet wrote:
> From: Eric Dumazet <edumazet@...gle.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)


> 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.