+#ifdef CONFIG_MEMORY_MIRROR + if (change_to_mirror(gfp_mask, ac.high_zoneidx)) + ac.migratetype = MIGRATE_MIRROR; +#endif We may have to be smarter than this here. I'd like to encourage the enterprise Linux distributions to set CONFIG_MEMORY_MIRROR=y But the reality is that most systems will not configure any mirrored memory - so we don't want the common code path for memory allocation to call functions that set the migrate type, try to allocate and then fall back to a non-mirror when that may be a complete waste of time. Maybe a global "got_mirror" that is true if we have some mirrored memory. Then code is if (got_mirror && change_to_mirror(...)) -- 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