Messages in this thread | | | Subject | Re: [PATCH v1] kthread/smpboot: Serialize kthread parking against wakeup | From | "Kohli, Gaurav" <> | Date | Mon, 7 May 2018 16:53:51 +0530 |
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Corrected the formatting, Sorry for spam.
> > HI Peter, > > We have tested with new patch and still seeing same issue, in this dumps > we don't have debug traces, but seems there still exist race from code > review , Can you please check it once: > > Controller Thread CPUHP Thread > takedown_cpu > kthread_park > kthread_parkme > Set KTHREAD_SHOULD_PARK > smpboot_thread_fn > set Task interruptible > > > wake_up_process > > Kthread_parkme > SET TASK_PARKED > schedule > raw_spin_lock(&rq->lock) > > context_switch > > finish_lock_switch > > > > Case TASK_PARKED > kthread_park_complete > > > SET TASK_INTERRUPTIBLE > > > And also seeing the same warning during unpark of cpuhp from controller: > if (!wait_task_inactive(p, state)) { > WARN_ON(1); > return; > } > 325.065893] [<ffffff8920ed0200>] kthread_unpark+0x80/0xd8 > [ 325.065902] [<ffffff8920eab754>] bringup_cpu+0xa0/0x12c > [ 325.065910] [<ffffff8920eaae90>] cpuhp_invoke_callback+0xb4/0x5c8 > [ 325.065917] [<ffffff8920eabd98>] cpuhp_up_callbacks+0x3c/0x154 > [ 325.065924] [<ffffff8920ead220>] _cpu_up+0x134/0x208 > [ 325.065931] [<ffffff8920ead45c>] do_cpu_up+0x168/0x1a0 > [ 325.065938] [<ffffff8920ead4b8>] cpu_up+0x24/0x30 > [ 325.065948] [<ffffff89215b1408>] cpu_subsys_online+0x20/0x2c > [ 325.065956] [<ffffff89215aac64>] device_online+0x70/0xb4 > [ 325.065962] [<ffffff89215aad78>] online_store+0xd0/0xdc > [ 325.065971] [<ffffff89215a7424>] dev_attr_store+0x40/0x54 > [ 325.065982] [<ffffff89210d8a98>] sysfs_kf_write+0x5c/0x74 > [ 325.065988] [<ffffff89210d7b9c>] kernfs_fop_write+0xcc/0x1ec > [ 325.065999] [<ffffff8921049288>] vfs_write+0xb4/0x1d0 > [ 325.066006] [<ffffff892104a858>] SyS_write+0x60/0xc0 > [ 325.066014] [<ffffff8920e83770>] el0_svc_naked+0x24/0x28 > > > And after this same crash occured: > [ 325.521307] [<ffffff8920ed4aac>] smpboot_thread_fn+0x26c/0x2c8 > [ 325.527295] [<ffffff8920ecfb24>] kthread+0xf4/0x108 > > I will put more debug ftraces to check what is going on exactly. > > Regards > Gaurav > > > >
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