netdev - Re: tcp bw in 2.6

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]

Message-ID: <20071002094726.154fc619@freepuppy.rosehill>
Date:	Tue, 2 Oct 2007 09:47:26 -0700
From:	Stephen Hemminger <shemminger@...ux-foundation.org>
To:	lm@...mover.com (Larry McVoy)
Cc:	lm@...mover.com, Herbert Xu <herbert@...dor.apana.org.au>,
	torvalds@...ux-foundation.org, davem@...emloft.net,
	wscott@...mover.com, netdev@...r.kernel.org
Subject: Re: tcp bw in 2.6

On Tue, 2 Oct 2007 09:25:34 -0700
lm@...mover.com (Larry McVoy) wrote:

> > If the server side is the source of the data, i.e, it's transfer is a 
> > write loop, then I get the bad behaviour.  
> > ...
> > So is this a bug or intentional?
> 
> For whatever it is worth, I believed that we used to get better performance
> from the same hardware.  My guess is that it changed somewhere between
> 2.6.15-1-k7 and 2.6.18-5-k7.

For the period from 2.6.15 to 2.6.18, the kernel by default enabled TCP
Appropriate Byte Counting. This caused bad performance on applications that
did small writes.

-- 
Stephen Hemminger <shemminger@...ux-foundation.org>
-
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