From: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
To: Neal Cardwell <ncardwell@google.com>
Cc: Michael Tuexen <michael.tuexen@lurchi.franken.de>,
nhorman@tuxdriver.com, Dmitry Vyukov <dvyukov@google.com>,
lucien.xin@gmail.com, Netdev <netdev@vger.kernel.org>,
linux-sctp@vger.kernel.org, David Miller <davem@davemloft.net>,
dsa@cumulusnetworks.com, Eric Dumazet <edumazet@google.com>,
syzkaller@googlegroups.com
Subject: Re: [PATCH net] sctp: not allow to set rto_min with a value below 200 msecs
Date: Tue, 29 May 2018 14:06:04 -0300 [thread overview]
Message-ID: <20180529170604.GD3788@localhost.localdomain> (raw)
In-Reply-To: <CADVnQymCNEtQFThsbQ0u7jirx24i45f5L7P-2dPf8omkshqwmg@mail.gmail.com>
On Tue, May 29, 2018 at 12:03:46PM -0400, Neal Cardwell wrote:
> On Tue, May 29, 2018 at 11:45 AM Marcelo Ricardo Leitner <
> marcelo.leitner@gmail.com> wrote:
> > - patch2 - fix rtx attack vector
> > - Add the floor value to rto_min to HZ/20 (which fits the values
> > that Michael shared on the other email)
>
> I would encourage allowing minimum RTO values down to 5ms, if the ACK
> policy in the receiver makes this feasible. Our experience is that in
> datacenter environments it can be advantageous to allow timer-based loss
> recoveries using timeout values as low as 5ms, e.g.:
Thanks Neal. On Xin's tests, the hearbeat timer becomes an issue at
~25ms already. Xin, can you share more details on the hw, which CPU
was used?
Anyway, what about we add a floor to rto_max too, so that RTO can
actually grow into something bigger that don't hog the CPU? Like:
rto_min floor = 5ms
rto_max floor = 50ms
Marcelo
next prev parent reply other threads:[~2018-05-29 17:06 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-05-25 17:41 [PATCH net] sctp: not allow to set rto_min with a value below 200 msecs Xin Long
2018-05-25 19:13 ` Neil Horman
2018-05-26 15:42 ` Michael Tuexen
2018-05-26 15:50 ` Dmitry Vyukov
2018-05-27 1:01 ` Neil Horman
2018-05-28 19:43 ` Marcelo Ricardo Leitner
2018-05-29 11:41 ` Neil Horman
2018-05-29 13:06 ` Michael Tuexen
2018-05-29 15:45 ` Marcelo Ricardo Leitner
2018-05-29 16:03 ` Neal Cardwell
2018-05-29 17:06 ` Marcelo Ricardo Leitner [this message]
2018-05-29 17:45 ` Xin Long
2018-05-29 18:02 ` Marcelo Ricardo Leitner
2018-06-04 8:34 ` Dmitry Vyukov
2018-06-04 12:15 ` Xin Long
2018-05-27 8:58 ` Michael Tuexen
2018-05-28 18:56 ` Marcelo Ricardo Leitner
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