On Wed, Jan 20, 2010 at 04:10:53PM +0000, Russell King - ARM Linux wrote: > On Wed, Jan 20, 2010 at 04:05:25PM +0000, Ben Dooks wrote: > > On Wed, Jan 20, 2010 at 03:55:10PM +0000, Russell King - ARM Linux wrote: > > > On Wed, Jan 20, 2010 at 03:34:11PM +0000, Ben Dooks wrote: > > > > I've been looking at support for a new machine type where the > > > > current system is using DISCONTIGMEM as the 1G memory map has > > > > 4x256M RAM ranges which may not all be filled. > > > > > > Firstly, use sparsemem, unless you intentionally want to spend more > > > cycles in the kernel. > > > > Ok, any idea if that will fix the problem in this case? > > It _may_ do, because it doesn't have the concept of NUMA nodes (which > is what discontigmem is all about.) > > > Should I send a patch to detect bad DISCONTIGMEM setup? I think that > > a check of PHYS_TO_PFN((start+end) != PHYS_TO_PFN(start)) should be > > safe in all cases? > > Just move away from discontigmem completely. Sparsemem can do everything > we need on ARM at a lesser cost. As I say above, discontigmem is really > for NUMA platforms, and ARM is not a NUMA platform. No one on ARM should > be going anywhere near discontigmem. Thanks, we seem to have working sparsemem support now so I will try and ensure that is what gets sumitted. -- Ben Q: What's a light-year? A: One-third less calories than a regular year. -- To unsubscribe from this list: send the line "unsubscribe linux-samsung-soc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html