> On Nov 24, 2016, at 5:15 AM, Michal Hocko <mhocko@xxxxxxxxxx> wrote: > >> * No rcu_* warnings on that machine with 4.7.2, but with 4.8.4 , 4.8.6 , >> 4.8.8 and now 4.9.0-rc5+Pauls patch > > I assume you haven't tried the Linus 4.8 kernel without any further > stable patches? Just to be sure we are not talking about some later > regression which found its way to the stable tree. We are also seeing this frequently on our fleet since moving from 4.7.x to 4.8. This is from a machine running vanilla 4.8.6 just a few moments ago: INFO: rcu_sched detected stalls on CPUs/tasks: 13-...: (420 ticks this GP) idle=ce1/140000000000000/0 softirq=225550784/225550904 fqs=87105 (detected by 26, t=600030 jiffies, g=68185325, c=68185324, q=344996) Task dump for CPU 13: kswapd1 R running task 12200 1840 2 0x00000808 0000000000000001 0000000000000034 000000000000012b 0000000000003139 ffff8b643fffb000 ffff8b028cee7cf8 ffff8b028cee7cf8 ffff8b028cee7d08 ffff8b028cee7d08 ffff8b028cee7d18 ffff8b028cee7d18 ffff8b0200000000 Call Trace: [] ? shrink_node+0xcd/0x2f0 [] ? kswapd+0x304/0x710 [] ? mem_cgroup_shrink_node+0x160/0x160 [] ? kthread+0xc4/0xe0 [] ? ret_from_fork+0x1f/0x40 [] ? kthread_worker_fn+0x140/0x140 The machine will lag terribly during these occurrences .. some will eventually recover, some will spiral down and require a reboot. -Chris -- To unsubscribe from this list: send the line "unsubscribe linux-xfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
