SKGE backport to 2.4 : success

SKGE backport to 2.4 : success

[Willy Tarreau]

Hi Stephen,

In my own kernels, I've added your backport of SKGE to 2.4 that I found
here :

   http://developer.osdl.org/shemminger/releases/skge-sky2-backport.tar.bz2

It seems to work pretty well compared to the original syskonnect driver
(up to and including 8.36). Several people around me have reported very
slow NFS operations with the official driver, which I finally attributed
to a strange effect of UDP packets not going out after a while until they
get "pushed" by a TCP packet. I even noticed the problem at the company
and we turned the NFS server to an unused 100 Mbps card to workaround the
problem before being able to fully ananlyze the problem.

It seems your driver is getting mature and its performance is very close to
the official one, while its code is smaller and apparently more reliable. I
was thinking about merging it in mainline 2.4 as a fix for people having
trouble with the syskonnect driver. It might also be easier to backport fixes
from 2.6 to 2.4 when the driver is the same.

I don't think we risk any regression because it won't replace an existing
driver, but will provide one to people who are used to download new versions
from an external tree.

Also, I'm not yet sure whether I would also backport the sky2 driver, because
I know about a handful boxes running in production with the official one with
88E8053 chips at high packet rates with no trouble at all. Anyway, as long as
the backport does not prevent them from using the external driver, there
should be no problem.

I'd like to get your opinion on this matter, and of course, Jeff's and Davem's.

Thanks in advance,
Willy

Re: SKGE backport to 2.4 : success

[Willy Tarreau]

Hi Stephen,

I don't know if you received my mail since I got no reply.

Thanks in advance for your comments,
Willy

On Sat, Oct 28, 2006 at 10:57:07PM +0200, Willy Tarreau wrote:
> Hi Stephen,
> 
> In my own kernels, I've added your backport of SKGE to 2.4 that I found
> here :
> 
>    http://developer.osdl.org/shemminger/releases/skge-sky2-backport.tar.bz2
> 
> It seems to work pretty well compared to the original syskonnect driver
> (up to and including 8.36). Several people around me have reported very
> slow NFS operations with the official driver, which I finally attributed
> to a strange effect of UDP packets not going out after a while until they
> get "pushed" by a TCP packet. I even noticed the problem at the company
> and we turned the NFS server to an unused 100 Mbps card to workaround the
> problem before being able to fully ananlyze the problem.
> 
> It seems your driver is getting mature and its performance is very close to
> the official one, while its code is smaller and apparently more reliable. I
> was thinking about merging it in mainline 2.4 as a fix for people having
> trouble with the syskonnect driver. It might also be easier to backport fixes
> from 2.6 to 2.4 when the driver is the same.
> 
> I don't think we risk any regression because it won't replace an existing
> driver, but will provide one to people who are used to download new versions
> from an external tree.
> 
> Also, I'm not yet sure whether I would also backport the sky2 driver, because
> I know about a handful boxes running in production with the official one with
> 88E8053 chips at high packet rates with no trouble at all. Anyway, as long as
> the backport does not prevent them from using the external driver, there
> should be no problem.
> 
> I'd like to get your opinion on this matter, and of course, Jeff's and Davem's.
> 
> Thanks in advance,
> Willy
> 

Re: SKGE backport to 2.4 : success

[Stephen Hemminger]

On Sat, 4 Nov 2006 22:08:55 +0100
Willy Tarreau <w@1wt.eu> wrote:

> Hi Stephen,
> 
> I don't know if you received my mail since I got no reply.
> 
> Thanks in advance for your comments,
> Willy
> 
> On Sat, Oct 28, 2006 at 10:57:07PM +0200, Willy Tarreau wrote:
> > Hi Stephen,
> > 
> > In my own kernels, I've added your backport of SKGE to 2.4 that I found
> > here :
> > 
> >    http://developer.osdl.org/shemminger/releases/skge-sky2-backport.tar.bz2
> > 
> > It seems to work pretty well compared to the original syskonnect driver
> > (up to and including 8.36). Several people around me have reported very
> > slow NFS operations with the official driver, which I finally attributed
> > to a strange effect of UDP packets not going out after a while until they
> > get "pushed" by a TCP packet. I even noticed the problem at the company
> > and we turned the NFS server to an unused 100 Mbps card to workaround the
> > problem before being able to fully ananlyze the problem.
> > 
> > It seems your driver is getting mature and its performance is very close to
> > the official one, while its code is smaller and apparently more reliable. I
> > was thinking about merging it in mainline 2.4 as a fix for people having
> > trouble with the syskonnect driver. It might also be easier to backport fixes
> > from 2.6 to 2.4 when the driver is the same.
> > 
> > I don't think we risk any regression because it won't replace an existing
> > driver, but will provide one to people who are used to download new versions
> > from an external tree.
> > 
> > Also, I'm not yet sure whether I would also backport the sky2 driver, because
> > I know about a handful boxes running in production with the official one with
> > 88E8053 chips at high packet rates with no trouble at all. Anyway, as long as
> > the backport does not prevent them from using the external driver, there
> > should be no problem.
> > 
> > I'd like to get your opinion on this matter, and of course, Jeff's and Davem's.
> > 
> > Thanks in advance,
> > Willy
> > 


The backport needs to be updated. It is of older code.  I plan to do a new
backport this week. The backport version doesn't use NAPI, because of issues
with not wanting to change netdevice.h. For a good 2.4 version, I would
make a version that was closer to 2.6 code (using NAPI).

I did the backport because one of the equipment donors gave a VPN box whose
base OS is RHEL based on 2.4.


-- 
Stephen Hemminger <shemminger@osdl.org>

Re: SKGE backport to 2.4 : success

[Willy Tarreau]

On Mon, Nov 06, 2006 at 10:56:09AM -0800, Stephen Hemminger wrote:
> On Sat, 4 Nov 2006 22:08:55 +0100
> Willy Tarreau <w@1wt.eu> wrote:
> 
> > Hi Stephen,
> > 
> > I don't know if you received my mail since I got no reply.
> > 
> > Thanks in advance for your comments,
> > Willy
> > 
> > On Sat, Oct 28, 2006 at 10:57:07PM +0200, Willy Tarreau wrote:
> > > Hi Stephen,
> > > 
> > > In my own kernels, I've added your backport of SKGE to 2.4 that I found
> > > here :
> > > 
> > >    http://developer.osdl.org/shemminger/releases/skge-sky2-backport.tar.bz2
> > > 
> > > It seems to work pretty well compared to the original syskonnect driver
> > > (up to and including 8.36). Several people around me have reported very
> > > slow NFS operations with the official driver, which I finally attributed
> > > to a strange effect of UDP packets not going out after a while until they
> > > get "pushed" by a TCP packet. I even noticed the problem at the company
> > > and we turned the NFS server to an unused 100 Mbps card to workaround the
> > > problem before being able to fully ananlyze the problem.
> > > 
> > > It seems your driver is getting mature and its performance is very close to
> > > the official one, while its code is smaller and apparently more reliable. I
> > > was thinking about merging it in mainline 2.4 as a fix for people having
> > > trouble with the syskonnect driver. It might also be easier to backport fixes
> > > from 2.6 to 2.4 when the driver is the same.
> > > 
> > > I don't think we risk any regression because it won't replace an existing
> > > driver, but will provide one to people who are used to download new versions
> > > from an external tree.
> > > 
> > > Also, I'm not yet sure whether I would also backport the sky2 driver, because
> > > I know about a handful boxes running in production with the official one with
> > > 88E8053 chips at high packet rates with no trouble at all. Anyway, as long as
> > > the backport does not prevent them from using the external driver, there
> > > should be no problem.
> > > 
> > > I'd like to get your opinion on this matter, and of course, Jeff's and Davem's.
> > > 
> > > Thanks in advance,
> > > Willy
> > > 
> 
> 
> The backport needs to be updated. It is of older code.  I plan to do a new
> backport this week. The backport version doesn't use NAPI, because of issues
> with not wanting to change netdevice.h. For a good 2.4 version, I would
> make a version that was closer to 2.6 code (using NAPI).

That would be perfect, it would make backport of fixes even easier. I have
turned last version into a patch against 2.4.33 for in-tree inclusion, so
if you're interested in getting it for the Config.in, Makefiles and
Configure.help, do not hesitate.

> I did the backport because one of the equipment donors gave a VPN box whose
> base OS is RHEL based on 2.4.

It's amazing how having the hardware stimulates development, isn't it? :-)

Tbanks,
Willy