On 06/28/2012 10:06 AM, David Rientjes wrote: > On Thu, 28 Jun 2012, Minchan Kim wrote: > >>>>>>> https://lkml.org/lkml/2012/6/21/30 >>>>> >>> Not sure if Jim is using memcg; if not, then this won't be helpful. >>> >> >> >> It doesn't related to memcg. >> if compaction_alloc can't find suitable migration target, it returns NULL. >> Then, migrate_pages should be exit. >> > > If isolate_freepages() is going to fail, then this zone should have been > skipped when checking for compaction_suitable(). In Jim's perf output, > compaction_suitable() returns COMPACT_CONTINUE for a transparent hugepage. > Why is zone_watermark_ok(zone, 0 low_wmark + 1024, 0, 0) succeeding if > isolate_freepages() is going to fail? > zone_watermark_ok doesn't consider migratetype but suitable_migrate_target does consider one. > -- > 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> > -- Kind regards, Minchan Kim -- 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>