[<prev] [next>] [<thread-prev] [day] [month] [year] [list]
Message-ID: <CAB_+Fg6aJ66zp0VUK4r+AxV2icskww+rHsvv05Ug=6tU=Zbyhg@mail.gmail.com>
Date: Wed, 26 Feb 2014 11:52:49 -0800
From: Nandita Dukkipati <nanditad@...gle.com>
To: Neal Cardwell <ncardwell@...gle.com>
Cc: Per Hurtig <per.hurtig@....se>, Yuchung Cheng <ycheng@...gle.com>,
netdev <netdev@...r.kernel.org>,
David Miller <davem@...emloft.net>,
Eric Dumazet <edumazet@...gle.com>,
Anna Brunström <anna.brunstrom@....se>,
Andreas Petlund <apetlund@...ula.no>,
Michael Welzl <michawe@....uio.no>,
Ilpo Järvinen <ilpo.jarvinen@...sinki.fi>
Subject: Re: [PATCH 1/1] net: tcp: RTO restart
On Wed, Feb 26, 2014 at 6:57 AM, Neal Cardwell <ncardwell@...gle.com> wrote:
> On Wed, Feb 26, 2014 at 4:50 AM, Per Hurtig <per.hurtig@....se> wrote:
>> Also, as your setup includes TLP we only have the RTO restart over TLP gain to start
>> with.
>
> My gut says the next thing to try is applying the "RTO restart" idea
> to the scheduling of the TLP probe (scheduling the TLP probe for
> write_queue_head_skb->when + tlp_timeout). Doing an RTO earlier can be
> a very bad thing, due to reseting the cwnd to 1. But doing a TLP
> earlier does not have much downside, and could have significant
> latency savings (though maybe Nandita already tried this at some
> point)...
+1 for applying RTO restart idea to scheduling a TLP. The thinking
with TLP at that time, was to send a probe approximately 1.5RTT after
the last "event" (which could be the transmit of a data packet or
receipt of an ACK). I did not try scheduling at
write_queue_head_skb->when + tlp_timeout, but I think it's worth an
experiment (may increase spurious TLPs by some amount which may be
OK).
Nandita
--
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
Powered by blists - more mailing lists