On Tue, Jan 31, 2017 at 4:48 AM, Mike Galbraith <efault@xxxxxx> wrote: > On Tue, 2017-01-31 at 16:30 +0530, Sachin Sant wrote: >> Trimming the cc list. >> >> > > I assume I should be worried? >> > >> > Thanks for the report. No need to worry, the bug has existed for a >> > while, this patch just turns on the warning ;-) >> > >> > The following commit queued up in tip/sched/core should fix your >> > issues (assuming you see the same callstack on all your powerpc >> > machines): >> > >> > https://git.kernel.org/cgit/linux/kernel/git/tip/tip.git/commit/?h=sched/core&id=1b1d62254df0fe42a711eb71948f915918987790 >> >> I still see this warning with today’s next running inside PowerVM LPAR >> on a POWER8 box. The stack trace is different from what Michael had >> reported. >> >> Easiest way to recreate this is to Online/offline cpu’s. > > (Ditto tip.today, x86_64 + hotplug stress) <> I'm also seeing a splat in the mmots tree with v4.10-rc5-mmots-2017-01-26-15-49, which pulled in this commit by merging with next. Just booting on an x86_64 VM gives me this: [ 13.090436] ------------[ cut here ]------------ [ 13.090577] WARNING: CPU: 8 PID: 1 at kernel/sched/sched.h:804 update_load_avg+0x85b/0xb80 [ 13.090577] rq->clock_update_flags < RQCF_ACT_SKIP [ 13.090578] Modules linked in: dax_pmem dax nd_pmem nd_btt nd_e820 libnvdimm [ 13.090582] CPU: 8 PID: 1 Comm: systemd Not tainted 4.10.0-rc5-mm1-00313-g5c0c3d7-dirty #10 [ 13.090583] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.9.1-0-gb3ef39f-prebuilt.qemu-project.org 04/01/2014 [ 13.090583] Call Trace: [ 13.090585] dump_stack+0x86/0xc3 [ 13.090586] __warn+0xcb/0xf0 [ 13.090588] warn_slowpath_fmt+0x5f/0x80 [ 13.090590] update_load_avg+0x85b/0xb80 [ 13.090591] ? debug_smp_processor_id+0x17/0x20 [ 13.090593] detach_task_cfs_rq+0x3f/0x210 [ 13.090594] task_change_group_fair+0x24/0x100 [ 13.090596] sched_change_group+0x5f/0x110 [ 13.090597] sched_move_task+0x53/0x160 [ 13.090598] cpu_cgroup_attach+0x36/0x70 [ 13.090600] cgroup_migrate_execute+0x230/0x3f0 [ 13.090602] cgroup_migrate+0xce/0x140 [ 13.090603] ? cgroup_migrate+0x5/0x140 [ 13.090604] cgroup_attach_task+0x27f/0x3e0 [ 13.090606] ? cgroup_attach_task+0x9b/0x3e0 [ 13.090608] __cgroup_procs_write+0x30e/0x510 [ 13.090608] ? __cgroup_procs_write+0x70/0x510 [ 13.090610] cgroup_procs_write+0x14/0x20 [ 13.090611] cgroup_file_write+0x44/0x1e0 [ 13.090613] kernfs_fop_write+0x13c/0x1c0 [ 13.090614] __vfs_write+0x37/0x160 [ 13.090615] ? rcu_read_lock_sched_held+0x4a/0x80 [ 13.090616] ? rcu_sync_lockdep_assert+0x2f/0x60 [ 13.090617] ? __sb_start_write+0x10d/0x220 [ 13.090618] ? vfs_write+0x19b/0x1f0 [ 13.090619] ? security_file_permission+0x3b/0xc0 [ 13.090620] vfs_write+0xcb/0x1f0 [ 13.090621] SyS_write+0x58/0xc0 [ 13.090623] entry_SYSCALL_64_fastpath+0x1f/0xc2 [ 13.090623] RIP: 0033:0x7f8b7c1be210 [ 13.090624] RSP: 002b:00007ffe73febfd8 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 [ 13.090625] RAX: ffffffffffffffda RBX: 000055a84870a7e0 RCX: 00007f8b7c1be210 [ 13.090625] RDX: 0000000000000004 RSI: 000055a84870aa10 RDI: 0000000000000033 [ 13.090626] RBP: 0000000000000000 R08: 000055a84870a8c0 R09: 00007f8b7dbda900 [ 13.090627] R10: 000055a84870aa10 R11: 0000000000000246 R12: 0000000000000000 [ 13.090627] R13: 000055a848775360 R14: 000055a84870a7e0 R15: 0000000000000033 [ 13.090629] ---[ end trace ba535936c2409043 ]--- -- To unsubscribe from this list: send the line "unsubscribe linux-next" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
