Hi, On Tue, Jun 14, 2011 at 06:03:00PM +0200, Arnd Bergmann wrote: > On Tuesday 14 June 2011, Michal Nazarewicz wrote: > > On Tue, 14 Jun 2011 15:49:29 +0200, Arnd Bergmann <arnd@xxxxxxxx> wrote: > > > Please explain the exact requirements that lead you to defining multiple > > > contexts. > > > > Some devices may have access only to some banks of memory. Some devices > > may use different banks of memory for different purposes. > > For all I know, that is something that is only true for a few very special > Samsung devices, and is completely unrelated of the need for contiguous > allocations, so this approach becomes pointless as soon as the next > generation of that chip grows an IOMMU, where we don't handle the special > bank attributes. Also, the way I understood the situation for the Samsung > SoC during the Budapest discussion, it's only a performance hack, not a > functional requirement, unless you count '1080p playback' as a functional > requirement. Hm, I think that was something similar but not quite the same: talking about having allocations split to lie between two banks of RAM to maximise the read/write speed for performance reasons. That's something that can be handled in the allocator, rather than an API constraint, as this is. Not that I know of any hardware which is limited as such, but eh. Cheers, Daniel -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxxx For more info on Linux MM, see: http://www.linux-mm.org/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>