Hello, On Fri, Jan 03, 2014 at 02:08:52PM -0800, Laura Abbott wrote: > On 1/3/2014 10:23 AM, Dave Hansen wrote: > >On 01/02/2014 01:53 PM, Laura Abbott wrote: > >>The goal here is to allow as much lowmem to be mapped as if the block of memory > >>was not reserved from the physical lowmem region. Previously, we had been > >>hacking up the direct virt <-> phys translation to ignore a large region of > >>memory. This did not scale for multiple holes of memory however. > > > >How much lowmem do these holes end up eating up in practice, ballpark? > >I'm curious how painful this is going to get. > > > > In total, the worst case can be close to 100M with an average case > around 70M-80M. The split and number of holes vary with the layout > but end up with 60M-80M one hole and the rest in the other. One more thing I'd like to know is how bad direct virt <->phys tranlsation in scale POV and how often virt<->phys tranlsation is called in your worload so what's the gain from this patch? Thanks. -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>