Re: [Cbe-oss-dev] [PATCH] ps3: gigabit ethernet driver for PS3, take3

Re: [Cbe-oss-dev] [PATCH] ps3: gigabit ethernet driver for PS3, take3

[Linas Vepstas]

On Thu, Jul 05, 2007 at 11:47:20AM -0500, jschopp wrote:
> 
> This is the third submission of the network driver for PS3.
> The differences from the previous one are:

I notice that this mostly a cut-n-paste of a very old version
of the spidernet device driver.  Please note that the old
spidernet had absolutely disasterous performance for transmit;
it also had a variety of crazy hangs and lockups under 
high-stress conditions; or NFS operation, or certain back-to-back
tcp usage scenarios. A few dozen bugfixes went in since
the time that the gelic snapshot was taken.

Wouldn't it be better to just add the hypervisor bits-n-pieces 
to spidernet?  That way, you get not only the various fixes, but 
also the benefit of fairly regular testing...


--linas

Re: [Cbe-oss-dev] [PATCH] ps3: gigabit ethernet driver for PS3, take3

[Akira Tsukamoto]

Hi,

On Fri, 6 Jul 2007 13:02:41 -0500, linas@austin.ibm.com (Linas Vepstas) mentioned: 
> of the spidernet device driver.  Please note that the old
> spidernet had absolutely disasterous performance for transmit;
> it also had a variety of crazy hangs and lockups under 
> high-stress conditions; or NFS operation, or certain back-to-back
> tcp usage scenarios. A few dozen bugfixes went in since
> the time that the gelic snapshot was taken.

I think we know the problems of old spidernet issues, we uses QS20 also 
in our lab.
Current gelic has fixed them all separated from your work and it have no 
remaining issues or performance problem.
In our measurement, PS3 network performance is better than IBM QS20 right
now.
I totally understand difficultness of your effort that fixing spidernet 
without decent documentation which we have, but the changes we made was 
significantly large as you see if you diff gelic driver with current 
spidernet driver (totally different), so the conclusion of discussion at 
3C common-linux wg (Sony, IBM and Toshiba) was to include main line 
differently first then consider unifying it later. Otherwise we won't 
able to see PS3 network stack working for long time.

Akira
-- 
Akira Tsukamoto
Sony Computer Entertainment Inc. 
Computer Development Div. Distributed OS Development Dept. 
Japan

Re: [Cbe-oss-dev] [PATCH] ps3: gigabit ethernet driver for PS3, take3

[Linas Vepstas]

On Mon, Jul 09, 2007 at 10:50:19AM +0900, Akira Tsukamoto wrote:
> Hi,
> 
> On Fri, 6 Jul 2007 13:02:41 -0500, linas@austin.ibm.com (Linas Vepstas) mentioned: 
> > of the spidernet device driver.  Please note that the old
> > spidernet had absolutely disasterous performance for transmit;
> > it also had a variety of crazy hangs and lockups under 
> > high-stress conditions; or NFS operation, or certain back-to-back
> > tcp usage scenarios. A few dozen bugfixes went in since
> > the time that the gelic snapshot was taken.
> 
> I think we know the problems of old spidernet issues, we uses QS20 also 
> in our lab.
> Current gelic has fixed them all separated from your work and it have no 
> remaining issues or performance problem.
> In our measurement, PS3 network performance is better than IBM QS20 right
> now.

!! Well, gee, I wish this plan had been made public. I'd spent something
between 3-6 months working full-time on spidernet issues. This was a lot
of work and effort.  Worse, this was *not* my main job; it was rather to 
help the neighbors prevent a disaster in the making.  Certainly, I would 
not have spent any time on this, if I'd known someone else was also working 
to fix the same bugs. :-(

> I totally understand difficultness of your effort that fixing spidernet 
> without decent documentation which we have, but the changes we made was 
> significantly large as you see if you diff gelic driver with current 
> spidernet driver (totally different), 

The differences are very large, because very large changes have been made
to the spidernet. However, a diff between gelic and the old spidernet is
much smaller.  So I'm somewhat confused by this.  Perhaps I am mistaken, 
and should read the code more carefully.

> so the conclusion of discussion at 
> 3C common-linux wg (Sony, IBM and Toshiba) 

?? What working group is this?  This is the first time that I am hearing
of it, and, as the only active spidernet maintainer, I'd hope to have
been a part of suc discussion. Oh well.

-- Linas Vepstas