On Tue, Apr 24, 2012 at 9:38 AM, Rik van Riel <riel@xxxxxxxxxx> wrote: > On 04/24/2012 12:36 PM, Ying Han wrote: > >> However, what if B frees a pages everytime before pages_scanned >> reaches the point, then we won't set zone->all_unreclaimable at all. >> If so, we reaches a livelock here... > > > If B keeps freeing pages, surely A will get a successful > allocation and there will not be a livelock? Ah, that is another piece of puzzle. We suspect the zone is under min_watermark due to previous alloc_flags (ALLOC_NO_WATERMARKS) and B returns the page under min which can not be allocated by A. Now we reset the zone->pages_scanned on freeing page regardless of the watermarks, so it is possible that zone is under min_watermark but !zone->all_unreclaimable. --Ying > > -- > All rights reversed -- 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/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>