When a high-order allocation fails, kswapd is kicked so that it reclaims at a higher-order to avoid direct reclaimers stall and to help GFP_ATOMIC allocations. Something has changed in recent kernels that affect the timing where high-order GFP_ATOMIC allocations are now failing with more frequency, particularly under pressure. This patch forces kswapd to notice sooner that high-order allocations are occuring.
Signed-off-by: Mel Gorman <[email protected]> --- mm/vmscan.c | 9 +++++++++ 1 files changed, 9 insertions(+), 0 deletions(-) diff --git a/mm/vmscan.c b/mm/vmscan.c index 64e4388..cd68109 100644 --- a/mm/vmscan.c +++ b/mm/vmscan.c @@ -2016,6 +2016,15 @@ loop_again: priority != DEF_PRIORITY) continue; + /* + * Exit quickly to restart if it has been indicated + * that higher orders are required + */ + if (pgdat->kswapd_max_order > order) { + all_zones_ok = 1; + goto out; + } + if (!zone_watermark_ok(zone, order, high_wmark_pages(zone), end_zone, 0)) all_zones_ok = 0; -- 1.6.3.3 -- To unsubscribe from this list: send the line "unsubscribe kernel-testers" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
