On Friday 29 October 2004 11:13, Johannes Erdfelt wrote: > > If usbfs instead grabbed a bunch of non-contiguous > > pages, copied the data into them from user-space, and then sent it (using > > scatter-gather io), then there is no longer any memory pressure problem. > > What's more, there would also be no reason not to increase the maximum > > data size from 16k to something much bigger, say 256k. Allowing bigger > > buffers should increase performance. > > Duh, that would be the obvious way to increase performance and > reliability. > > Not to mention it should be relatively easy to implement.
Yep, and you'd be able to clean up properly after an error in the middle of your N urbs ... the scatterlist code handles such things. Another tweak would be to remove the limit on transfer size. Use whatever algorithm you want to transfer the first chunk; for high speed, a scatterlist is *really* desirable. Then repeat for successive chunks ... until error, or all done. (And if you can't get enough buffers to use big chunks, then you could still make progress using smaller chunks...) - Dave ------------------------------------------------------- This SF.Net email is sponsored by: Sybase ASE Linux Express Edition - download now for FREE LinuxWorld Reader's Choice Award Winner for best database on Linux. http://ads.osdn.com/?ad_id=5588&alloc_id=12065&op=click _______________________________________________ [EMAIL PROTECTED] To unsubscribe, use the last form field at: https://lists.sourceforge.net/lists/listinfo/linux-usb-devel
