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 for Android: free password hash cracker in your pocket

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

Date:	Fri, 06 Feb 2015 09:48:19 -0800
From:	Rick Jones <rick.jones2@...com>
To:	Eric Dumazet <eric.dumazet@...il.com>,
	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`

> 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.

An alternative, if the application involved can make explicit 
setsockopt() calls to set SO_SNDBUF and/or SO_RCVBUF, is to tweak 
rmem_max and wmem_max and then let the application make the setsockopt() 
calls.

Which path one would take would depend on circumstances I suspect.

rick jones
--
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