[ECOS] Re: Problems with ppp and Windows

[Øyvind Harboe <oyvind dot harboe at zylin dot com>]

> Yes, sounds fine. In my case I'd be happy with just a debug message or 
> assert in cyg_net_malloc() when not enough memory is available. I would 
> think this should be a build option, rather than a default operation.

I've put together a memory allocation debug feature patch... 

http://ecos.sourceware.org/ml/ecos-discuss/2004-06/msg00161.html

Notice the complication that the networking stack sometimes goes to
sleep waiting for more memory to become availble. I've done my best to
allow for setting a breakpoint for the case where a function does not
return :-)



> I think the proper place to add some debug notification is at the usage 
> points of network mallocs. In the case of PPP, after the MALLOC() 
> failed, it ought to have done something about it or printed some debug, 
> rather than just carrying on broken.

Does it make any sense at all to bring up the PPP connection if these
initial allocations fail?

Note that I saw the lockup on accept() even if the VJC compression
buffers could be allocated.

> > - reduce memory requirements for PPP and freebsd networking stack. 
> 
> For PPP there are a bunch of configuration options that aren't covered 
> by the cyg_ppp_options_t structure. I've added a few options here to 
> handle authorisation for dialin connections. Similarly you could extend 
> it to disable things like VJ compression to reduce the memory requirements.

Care to share? :-)

> > - It is a bit hard to *know* how much memory is required. It would be nice to have a simple
> > way of figuring this out at compile time.
> 
> Difficult to gauge in advance I would think.

It may be difficult, but I can't imagine it being anything but
absolutely necessary to know in advance.


-- 
Øyvind Harboe
http://www.zylin.com



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