Re: New USB stack on FreeBSD w/Linux emulation layer coming
Oliver Neukum <[email protected]>
| Newsgroups | gmane.linux.usb.devel |
|---|---|
| Message-ID | <[email protected]> |
Am Mittwoch, 16. Mai 2007 16:41 schrieb David Brownell: > > in that when you have > > pre-allocated all buffers and all USB host controller descriptors, you will > > never get in the situation of not being able to allocate transfer descriptors > > on the fly, like done on Linux. > > That's not a failure mode that's been often observed on Linux. (Never, > in my own experience... which I admit has not focussed on that particular > type of stress load.) So it's hard to argue that it should motivate a > redesign of core APIs. We are seeing report of the networking stack exhausting the atomic pool. They are rare these days, but do exist. > Transfer descriptors are an artifact of one kind of host controller; > it'd be wrong to assume all HCDs use them. True. > The related issue that's been discussed is how to shrink submit paths, > giving lower overhead. The obvious way would be to shift more work into usb_alloc_urb() It would imply binding an URB to an endpoint at allocation. Regards Oliver ------------------------------------------------------------------------- This SF.net email is sponsored by DB2 Express Download DB2 Express C - the FREE version of DB2 express and take control of your XML. No limits. Just data. Click to get it now. http://sourceforge.net/powerbar/db2/ _______________________________________________ [email protected] To unsubscribe, use the last form field at: https://lists.sourceforge.net/lists/listinfo/linux-usb-devel