On Thu, Sep 06, 2012 at 06:44:04PM +0800, Shaohua Li wrote: > > isolate_migratepages_range() might isolate none pages, for example, when > zone->lru_lock is contended and compaction is async. In this case, we should > abort compaction, otherwise, compact_zone will run a useless loop and make > zone->lru_lock is even contended. > It might also isolate no pages because the range was 100% allocated and there were no free pages to isolate. This is perfectly normal and I suspect this patch effectively disables compaction. What problem did you observe that this patch is aimed at? -- 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>