Re: eepro100 troubles

From: Alan Cox (
Date: Thu Jun 08 2000 - 18:26:43 EST

> if the number of buffers outstanding is limited to 500, the card will
> complain about no buffers but will continue to operate. Once the number is
> allowed to grow to 1000, it will reset regularly and eventually fail. With
> 16M it will fail even with 500 buffers outstanding.

You need to retune the VM by the sound of that. The rest/retry cycles sound
like you've stolen so much memory at atomic priority the rest of the system
is taking defensive action 8)

> Typically you may need to hold as many as 5000-8000 buffers (maybe 30M for
> a 100Mb/s medium), so this is no even a cutting edge test.....

30Mbytes of buffers ?? your shaping algorithm sounds broken.

> In contrast, the same test on freebsd, the fxp driver will complain about
> not enough buffers (only once) but will continue to operate continuously
> without resets or gaps in operation, regardless of the amount of memory in
> the machine or the number of buffers held by the bandwidth manager. This is
> as expected: if memory isnt available frames will be dropped but operation
> will continue as best as is possible given the resources available.

BSD preallocates a network buffer pool we are UMA.

> It seems likely that the same test with one of linux' shaping mechanism can
> be done the same way.

The traffic shaper never gets about about 200 buffers.


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This archive was generated by hypermail 2b29 : Thu Jun 15 2000 - 21:00:40 EST