Hi, I booted the latest git today on a ppc64 box. When I pushed it into swap I noticed both kswapd's were using 100% CPU and the soft lockup detector suggested it was stuck in balance_pgdat: BUG: soft lockup - CPU#7 stuck for 23s! [kswapd1:359] Call Trace: [c00000000015e190] .balance_pgdat+0x150/0x940 [c00000000015eb2c] .kswapd+0x1ac/0x490 [c00000000009edbc] .kthread+0xbc/0xd0 [c00000000002142c] .kernel_thread+0x54/0x70 I haven't had time to bisect but I did notice we were looping here: diff --git a/mm/vmscan.c b/mm/vmscan.c index 7658fd6..c92bad2 100644 --- a/mm/vmscan.c +++ b/mm/vmscan.c @@ -2945,9 +2959,11 @@ out: if (zone->all_unreclaimable && priority != DEF_PRIORITY) continue; +#if 0 /* Would compaction fail due to lack of free memory? */ if (compaction_suitable(zone, order) == COMPACT_SKIPPED) goto loop_again; +#endif /* Confirm the zone is balanced for order-0 */ if (!zone_watermark_ok(zone, 0, After commenting it out the box is happy again. Anton -- 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>