On my v3.18-rc2 kernel isolate_freepages_block() sometimes shows up very high (>20%) in perf top during the configuration phase of software builds. It increases build time considerably. Unfortunately the issue is not 100% reproducible, because it appears only intermittently. And the symptoms vanish after a few minutes. I think the "mm, compaction" series from Vlastimil is to blame, but it's hard to be sure when bisection doesn't work. -- Markus -- 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>