On Fri, 2012-10-19 at 13:13 -0400, Rik van Riel wrote: > Would it make sense to have the normal page migration code always > work with the extra refcount, so we do not have to introduce a new > MIGRATE_FAULT migration mode? > > On the other hand, compaction does not take the extra reference...
Right, it appears to not do this, it gets pages from the pfn and zone->lock and the isolate_lru_page() call is the first reference. > Another alternative might be to do the put_page inside > do_prot_none_numa(). That would be analogous to do_wp_page > disposing of the old page for the caller. It'd have to be inside migrate_misplaced_page(), can't do before isolate_lru_page() or the page might disappear. Doing it after is (obviously) too late. > I am not real happy about NUMA migration introducing its own > migration mode... You didn't seem to mind too much earlier, but I can remove it if you want. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
