netdev - Re: [RFC PATCH v2] tcp: TCP Small Queues

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]

Date:	Tue, 10 Jul 2012 20:32:00 +0200
From:	Eric Dumazet <eric.dumazet@...il.com>
To:	Yuchung Cheng <ycheng@...gle.com>
Cc:	David Miller <davem@...emloft.net>, dave.taht@...il.com,
	netdev@...r.kernel.org, codel@...ts.bufferbloat.net,
	therbert@...gle.com, mattmathis@...gle.com, nanditad@...gle.com,
	ncardwell@...gle.com, andrewmcgr@...il.com
Subject: Re: [RFC PATCH v2] tcp: TCP Small Queues

On Tue, 2012-07-10 at 10:37 -0700, Yuchung Cheng wrote:
> On Tue, Jul 10, 2012 at 8:13 AM, Eric Dumazet <eric.dumazet@...il.com> wrote:

> > +
> > +               if (!sock_owned_by_user(sk)) {
> > +                       if ((1 << sk->sk_state) &
> > +                           (TCPF_CLOSE_WAIT | TCPF_ESTABLISHED))
> > +                               tcp_write_xmit(sk,
> > +                                              tcp_current_mss(sk),
> > +                                              0, 0,
> > +                                              GFP_ATOMIC);
> Is this case possible: app does a large send and immediately closes
> the socket. then
> the queue is throttled and tcp_write_xmit is called back when state is
> in TCP_FIN_WAIT1.
> 
> I think tcp_write_xmit should continue regardless of the current state
> because the
> send maybe throttled/delayed but state change is synchronous.
> 

I need testing some allowed states, I think.

Maybe I missed some states, but I dont think we should call
tcp_write_xmit() if socket is now in TIMEWAIT state ?

(because of tasklet delay, we might handle TX completion _after_ socket
state change)



--
To unsubscribe from this list: send the line "unsubscribe netdev" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html