On Fri, 2015-04-24 at 22:32 -0400, Rik van Riel wrote: > > The result would be that the kernel would allocate only > migratable > > pages within the CCAD device's memory, and even then only if > > memory was otherwise exhausted. > > Does it make sense to allocate the device's page tables in memory > belonging to the device? > > Is this a necessary thing with some devices? Jerome's HMM comes > to mind... In our case, the device's MMU shares the host page tables (which is why we can't use HMM, ie we can't have a page with different permissions on CPU vs. device which HMM does). However the device has a pretty fast path to system memory, the best thing we can do is pin the workload to the same chip the device is connected to so those page tables arent' too far away. Cheers, Ben. -- 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>