Am Donnerstag, 15. Dezember 2005 16:58 schrieb Sam Bishop:
> It's the writes I'm wondering about. It appears that the code allocates
> a new URB and buffer for each write. Once the write is completed, the
> associated URB and buffer are freed. But one of the ways I benchmark
> our download speeds is by filling a 4K buffer with valid packets and
> looping over a single write(2) call. With the CPU being so much faster
> than USB and an URB/buffer pair being allocated for each write, it would
> seem like it wouldn't be long before an -ENOMEM was returned.
>
> Of course, one answer would be, "Don't do that!" But with a sizable
> number of testers connected to the same host, I could see the result
> being the same, or similar, even during normal usage.
>
> What am I missing?
You are missing that you are looking at an example. If the problem
appears in real life, you need to have some reasonable upper limit,
eg. by using a semaphore.
Although this is a denial of service issue and possibly the skeleton driver
should deal with this issue.
Regards
Oliver
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