On Thu, Mar 19, 2015 at 06:29:47PM -0700, Linus Torvalds wrote: > And the VM_WRITE test should be stable and not have any subtle > interaction with the other changes that the numa pte things > introduced. It would be good to see if the profiles then pop something > *else* up as the performance difference (which I'm sure will remain, > since the 7m50s was so far off). > As a side-note, I did test a patch that checked pte_write and preserved it across both faults and setting the protections. It did not alter migration activity much but there was a drop in minor faults - 20% drop in autonumabench, 58% drop in xfsrepair workload. I'm assuming this is due to refaults to mark pages writable. The patch looks and is hacky so I won't post it to save people bleaching their eyes. I'll spend some time soon (hopefully today) at a smooth way of falling through to WP checks after trapping a NUMA fault. -- Mel Gorman SUSE Labs -- 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>