From mboxrd@z Thu Jan  1 00:00:00 1970
From: stephen mulcahy <smulcahy@gmail.com>
Subject: Re: forcedeth driver hangs under heavy load
Date: Tue, 13 Apr 2010 15:49:04 +0100
Message-ID: <4BC48460.4040001@gmail.com>
References: <4B9E6C60.7030300@atlanticlinux.ie>	 <20100315182220.GQ2763@decadent.org.uk> <4B9F5E5E.2060209@atlanticlinux.ie>				 <1270393967.8341.11.camel@localhost> <4BBCA19C.5080204@atlanticlinux.ie>				 <1270942606.6179.64.camel@localhost> <4BC2EF88.3060203@atlanticlinux.ie>				 <4BC31486.1090603@gmail.com> <1271076426.16881.21.camel@edumazet-laptop>				 <4BC31AA0.5070006@gmail.com> <4BC31DDE.7010005@gmail.com>				 <1271085862.16881.38.camel@edumazet-laptop> <4BC3461D.3070002@gmail.com>			 <1271091581.16881.41.camel@edumazet-laptop> <4BC44167.4080807@gmail.com>		 <1271155766.16881.245.camel@edumazet-laptop> <4BC44EC8.1010104@gmail.com>	 <1271160298.2098.0.camel@achroite.uk.solarflarecom.com>	 <4BC47F38.5040509@gmail.com> <1271169741.16881.437.camel@edumazet-laptop>
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Cc: Ben Hutchings <bhutchings@solarflare.com>,
	netdev <netdev@vger.kernel.org>,
	Ben Hutchings <ben@decadent.org.uk>,
	Ayaz Abdulla <aabdulla@nvidia.com>, 572201@bugs.debian.org
To: Eric Dumazet <eric.dumazet@gmail.com>
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Eric Dumazet wrote:
> Le mardi 13 avril 2010 =C3=A0 15:27 +0100, stephen mulcahy a =C3=A9cr=
it :
>> Ok, I've tried both of the following with my reproducer
>>
>> 1. ethtool -K eth0 tso off
>>
>> RESULT: reproducer causes multiple hosts to be come unresponsive on=20
>> first run.
>>
>> 2. ethtool -K eth0 tx off
>>
>> RESULT: reproducer runs three times without any hosts becoming unres=
ponsive.
>>
>> -stephen
>=20
> Thanks Stephen !
>=20
> Now some brave fouls to check the 6410 lines of this driver ? ;)
>=20
> Question of the day : Why TSO is broken in forcedeth ?
> Is it generically broken or is it broken for specific NICS ?
>=20

Actually, it is only when tx-checksumming is turned off that the proble=
m=20
  doesn't occur (so I'm not sure TSO is the problem).

Additionally, a google also turns up this existing Debian bug=20
http://bugs.debian.org/506419 which seems to be related.

-stephen