Re: [PATCH]dma rules violation in the option driver
David Brownell <[email protected]>
| Newsgroups | gmane.linux.usb.devel |
|---|---|
| Message-ID | <[email protected]> |
On Wednesday 28 March 2007 8:25 am, Alan Stern wrote: > On Tue, 27 Mar 2007, David Brownell wrote: > > > > Hmm... A CPU has to access all that data, and reading a cache line > > > at a time surely as better. Although on the other hand, it's something > > > streaming and thus just using the cache space for no good reason. > > > > Right. "Potentially". Displacing hot cachelines for use-once data > > will in various cases be a lose. > > It would be nice to see somewhere a more explicit and detailed discussion > of the tradeoffs. Under what conditions is it better to allocate DMA > memory rather than just using kmalloc() and calling dma_map_single()? Ideally that discussion would already be in Documentation/DMA-mapping.txt (or maybe Documentation/DMA-API.txt, but that's weak on such things). - Dave ------------------------------------------------------------------------- Take Surveys. Earn Cash. Influence the Future of IT Join SourceForge.net's Techsay panel and you'll get the chance to share your opinions on IT & business topics through brief surveys-and earn cash http://www.techsay.com/default.php?page=join.php&p=sourceforge&CID=DEVDEV _______________________________________________ [email protected] To unsubscribe, use the last form field at: https://lists.sourceforge.net/lists/listinfo/linux-usb-devel