On Mon, Jun 02, 2014 at 05:51:25PM -0700, David Rientjes wrote: > From: Hugh Dickins <hughd@xxxxxxxxxx> > > mem_cgroup_force_empty_list() can iterate a large number of pages on an lru and > mem_cgroup_move_parent() doesn't return an errno unless certain criteria, none > of which indicate that the iteration may be taking too long, is met. > > We have encountered the following stack trace many times indicating > "need_resched set for > 51000020 ns (51 ticks) without schedule", for example: > > scheduler_tick() > <timer irq> > mem_cgroup_move_account+0x4d/0x1d5 > mem_cgroup_move_parent+0x8d/0x109 > mem_cgroup_reparent_charges+0x149/0x2ba > mem_cgroup_css_offline+0xeb/0x11b > cgroup_offline_fn+0x68/0x16b > process_one_work+0x129/0x350 > > If this iteration is taking too long, we still need to do cond_resched() even > when an individual page is not busy. > > [rientjes@xxxxxxxxxx: changelog] > Signed-off-by: Hugh Dickins <hughd@xxxxxxxxxx> > Signed-off-by: David Rientjes <rientjes@xxxxxxxxxx> Acked-by: Johannes Weiner <hannes@xxxxxxxxxxx> -- 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>