On Wed, 17 May 2017, Benjamin Herrenschmidt wrote: > On Tue, 2017-05-16 at 09:43 +0100, Mel Gorman wrote: > > I'm not sure what you're asking here. migration is only partially > > transparent but a move_pages call will be necessary to force pages onto > > CDM if binding policies are not used so the cost of migration will be > > invisible. Even if you made it "transparent", the migration cost would > > be incurred at fault time. If anything, using move_pages would be more > > predictable as you control when the cost is incurred. > > One of the main point of this whole exercise is for applications to not > have to bother with any of this and now you are bringing all back into > their lap. You can provide a library that does it? > The base idea behind the counters we have on the link is for the HW to > know when memory is accessed "remotely", so that the device driver can > make decision about migrating pages into or away from the device, > especially so that applications don't have to concern themselves with > memory placement. Library can enquire about the current placement of the pages and move them if necessary? -- 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>
