netdev - Re: Throughput regression with `tcp: refine TSO autosizing`

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:	Fri, 06 Feb 2015 06:35:46 -0800
From:	Eric Dumazet <eric.dumazet@...il.com>
To:	Michal Kazior <michal.kazior@...to.com>
Cc:	Neal Cardwell <ncardwell@...gle.com>,
	linux-wireless <linux-wireless@...r.kernel.org>,
	Network Development <netdev@...r.kernel.org>,
	Eyal Perry <eyalpe@....mellanox.co.il>
Subject: Re: Throughput regression with `tcp: refine TSO autosizing`

On Fri, 2015-02-06 at 15:08 +0100, Michal Kazior wrote:

> Hmm.. I confirm it works. However the value at which I get full rate
> on a single flow is more than 2048K. Also using non-default
> wmem_default seems to introduce packet loss as per iperf reports at
> the receiver. I suppose this is kind of expected but on the other hand
> wmem_default=262992 and 5 flows of UDP max the device out with 0
> packet loss.

If you increase ability to flood on one flow, then you need to make sure
receiver has big rcvbuf as well.

echo 2000000 >/proc/sys/net/core/rmem_default

Otherwise it might drop bursts.

This is the kind of things that TCP does automatically, not UDP.


--
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