On Sat, 1 Feb 2020 09:31:17 +0800 Ming Lei <tom.leiming@xxxxxxxxx> wrote: > On Sat, Feb 1, 2020 at 2:02 AM John Garry <john.garry@xxxxxxxxxx> wrote: > > > > On 31/01/2020 17:51, John Garry wrote: > > > +- Keith > > > > + Marc, on rare chance that this is related to the GIC > > > > > > > > On 31/01/2020 10:58, Ming Lei wrote: > > >> On Fri, Jan 31, 2020 at 6:24 PM John Garry <john.garry@xxxxxxxxxx> wrote: > > >>> > > >>>>> [ 141.976109] Call trace: > > >>>>> [ 141.978550] __switch_to+0xbc/0x218 > > >>>>> [ 141.982029] blk_mq_run_work_fn+0x1c/0x28 > > >>>>> [ 141.986027] process_one_work+0x1e0/0x358 > > >>>>> [ 141.990025] worker_thread+0x40/0x488 > > >>>>> [ 141.993678] kthread+0x118/0x120 > > >>>>> [ 141.996897] ret_from_fork+0x10/0x18 > > >>>> > > >>>> Hi John, > > >>>> > > >>>> Thanks for your test! > > >>>> > > >>> > > >>> Hi Ming, > > >>> > > >>>> Could you test the following patchset and only the last one is changed? > > >>>> > > >>>> https://github.com/ming1/linux/commits/my_for_5.6_block > > >>> > > >>> For SCSI testing, I will ask my colleague Xiang Chen to test when he > > >>> returns to work. So I did not see this issue for my SCSI testing for > > >>> your original v5, but I was only using 1x as opposed to maybe 20x SAS > > >>> disks. > > >>> > > >>> BTW, did you test NVMe? For some reason I could not trigger a scenario > > >>> where we're draining the outstanding requests for a queue which is being > > >>> deactivated - I mean, the queues were always already quiesced. > > >> > > >> I run cpu hotplug test on both NVMe and SCSI in KVM, and fio just runs > > >> as expected. > > >> > > >> NVMe is often 1:1 mapping, so it might be a bit difficult to trigger > > >> draining in-flight IOs. > > > > > > I generally have a 4:1 mapping for my NVMe cards - so many CPUs. > > > > > > But more alarming is that I see this on every run: > > > > > > [ 246.378744] psci: CPU6 killed (polled 0 ms) > > > [ 246.427955] irq_migrate_all_off_this_cpu: 3 callbacks suppressed > > > [ 246.427956] IRQ 822: no longer affine to CPU7 > > > [ 246.438586] CPU7: shutdown > > > [ 246.441300] psci: CPU7 killed (polled 0 ms) > > > [ 247.015206] pcieport 0000:00:08.0: can't change power state from > > > D3cold to D0 (config space inaccessible) > > > Jobs: 6[ 267.503159] rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: > > > [ 267.509244] rcu: 25-...0: (1 GPs behind) > > > idle=11e/1/0x4000000000000000 softirq=1175/1177 fqs=2626 > > > [ 267.518283] (detected by 0, t=5255 jiffies, g=14001, q=1787) > > > [ 267.524016] Task dump for CPU 25: > > > [ 267.527318] irqbalance R running task 0 1275 1 > > > 0x00000002 > > > [ 267.534354] Call trace: > > > [ 267.536790] __switch_to+0xbc/0x218 > > > [ 267.540266] 0xffff800014c53d68 > > > Jobs: 6 (f=6): [R(6)][96.0%][r=0KiB/s[ 278.195193] nvme nvme1: > > > controller is down; will reset: CSTS=0xffffffff, PCI_STATUS=0xffff > > > ,w=0KiB/s][r=0,w=0 IOPS][eta 00m:[ 278.205197] nvme nvme0: controller > > > is down; will reset: CSTS=0xffffffff, PCI_STATUS=0xffff > > > Jobs: 6 (f=6): [R(6)][0.0%][r=0KiB/s,w=0KiB/s][r=0,w=0 IO[ 330.523157] > > > rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: > > > [ 330.529242] rcu: 25-...0: (1 GPs behind) > > > idle=11e/1/0x4000000000000000 softirq=1175/1177 fqs=10503 > > > [ 330.538366] (detected by 0, t=21010 jiffies, g=14001, q=2318) > > > [ 330.544186] Task dump for CPU 25: > > > [ 330.547488] irqbalance R running task 0 1275 1 > > > 0x00000002 > > > [ 330.554523] Call trace: > > > [ 330.556958] __switch_to+0xbc/0x218 > > > [ 330.560434] 0xffff800014c53d68 > > > [ 393.543155] rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: > > > [ 393.549242] rcu: 25-...0: (1 GPs behind) > > > idle=11e/1/0x4000000000000000 softirq=1175/1177 fqs=18379 > > > [ 393.558366] (detected by 8, t=36765 jiffies, g=14001, q=2385) > > > [ 393.564187] Task dump for CPU 25: > > > [ 393.567488] irqbalance R running task 0 1275 1 > > > 0x00000002 > > > [ 393.574523] Call trace: > > > [ 393.576960] __switch_to+0xbc/0x218 > > > [ 393.580435] 0xffff800014c53d68 > > > [ 456.567156] rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: > > > [ 456.573246] rcu: 25-...0: (1 GPs behind) > > > idle=11e/1/0x4000000000000000 softirq=1175/1177 fqs=26255 > > > [ 456.582389] (detected by 90, t=52520 jiffies, g=14001, q=2397) > > > [ 456.588296] Task dump for CPU 25: > > > [ 456.591601] irqbalance R running task 0 1275 1 > > > 0x00000002 > > > [ 456.598638] Call trace: > > > [ 456.601078] __switch_to+0xbc/0x218 > > > [ 456.604556] 0xffff800014c53d68 > > > [ 519.587152] rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: > > > [ 519.593235] rcu: 25-...0: (1 GPs behind) > > > idle=11e/1/0x4000000000000000 softirq=1175/1177 fqs=34131 > > > [ 519.602357] (detected by 90, t=68275 jiffies, g=14001, q=2405) > > > [ 519.608264] Task dump for CPU 25: > > > [ 519.611566] irqbalance R running task 0 1275 1 > > > 0x00000002 > > > [ 519.618601] Call trace: > > > [ 519.621036] __switch_to+0xbc/0x218 > > > [ 519.624511] 0xffff800014c53d68 > > > [ 582.603153] rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: > > > [ 582.609236] rcu: 25-...0: (1 GPs behind) > > > idle=11e/1/0x4000000000000000 softirq=1175/1177 fqs=42006 > > > [ 582.618358] (detected by 90, t=84029 jiffies, g=14001, q=2409) > > > [ 582.624265] Task dump for CPU 25: > > > [ 582.627567] irqbalance R running task 0 1275 1 > > > 0x00000002 > > > [ 582.634601] Call trace: > > > [ 582.637036] __switch_to+0xbc/0x218 > > > [ 582.640511] 0xffff800014c53d68 > > > > > > > > > I tested v5.5 and I cannot see this, but your branch is based in 5.5-rc2 > > > with lots of other stuff on top. The only thing I changed was > > > nvme.use_threaded_interrupts = 1. > > > > Uhh, now I do with v5.5: > > > > [ 705.354601] CPU22: shutdown > > [ 705.357395] psci: CPU22 killed (polled 0 ms) > > [ 705.402837] CPU23: shutdown > > [ 705.405630] psci: CPU23 killed (polled 0 ms) > > [ 705.666716] CPU24: shutdown > > [ 705.669512] psci: CPU24 killed (polled 0 ms) > > [ 705.966753] CPU25: shutdown > > [ 705.969548] psci: CPU25 killed (polled 0 ms) > > [ 706.250771] CPU26: shutdown=2347MiB/s,w=0KiB/s][r=601k,w=0 IOPS][eta > > 00m:13s] > > [ 706.253565] psci: CPU26 killed (polled 0 ms) > > [ 706.514728] CPU27: shutdown > > [ 706.517523] psci: CPU27 killed (polled 0 ms) > > [ 706.826708] CPU28: shutdown > > [ 706.829502] psci: CPU28 killed (polled 0 ms) > > [ 707.130916] CPU29: shutdown=2134MiB/s,w=0KiB/s][r=546k,w=0 IOPS][eta > > 00m:12s] > > [ 707.133714] psci: CPU29 killed (polled 0 ms) > > [ 707.439066] CPU30: shutdown > > [ 707.441870] psci: CPU30 killed (polled 0 ms) > > [ 707.706727] CPU31: shutdown > > [ 707.709526] psci: CPU31 killed (polled 0 ms) > > [ 708.521853] pcieport 0000:00:08.0: can't change power state from > > D3cold to D0 (config space inaccessible) > > [ 728.741808] rcu: INFO: rcu_preempt detected stalls on > > CPUs/tasks:80d:00h:35m:42s] > > [ 728.747895] rcu: 48-...0: (0 ticks this GP) > > idle=b3e/1/0x4000000000000000 softirq=5548/5548 fqs=2626 > > [ 728.757197] (detected by 63, t=5255 jiffies, g=40989, q=1890) > > [ 728.763018] Task dump for CPU 48: > > [ 728.766321] irqbalance R running task 0 1272 1 > > 0x00000002 > > [ 728.773358] Call trace: > > [ 728.775801] __switch_to+0xbc/0x218 > > [ 728.779283] gic_set_affinity+0x16c/0x1d8 > ... > > gic_set_affinity shouldn't have switched out, so looks like one gic > issue. Given that gic_set_affinity doesn't sleep, this looks pretty unlikely. And __irq_set_affinity() holds a spinlock with irq disabled, so I can't really explain how you'd get there. I've just booted a lockdep enabled v5.5 on my D05, moved SPIs around (because that's the only way to reach this code), and nothing caught fire. Either the stack trace isn't reliable (when I read things like "80d:00h:35m:42s" in the trace, I'm a bit suspicious), or CPU hotplug is doing something really funky here. M. -- Jazz is not dead. It just smells funny...
