Re: [PATCH v7 bpf-next 0/9] introduce support for XDP programs in CPUMAP

Lorenzo Bianconi
2020-07-17T16:31:17Z

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> On Fri, 17 Jul 2020 13:01:36 +0200
> Lorenzo Bianconi <lorenzo@kernel.org> wrote:
>
> > [...]
> >

[...]

> Was able to trigger it running the newly added selftest:
>
> virtme-init: console is ttyS0
> bash-5.0# ./test_progs -n 100
> #100/1 cpumap_with_progs:OK
> #100 xdp_cpumap_attach:OK
> Summary: 1/1 PASSED, 0 SKIPPED, 0 FAILED
> bash-5.0# [ 247.177168] INFO: task cpumap/0/map:3:198 blocked for more than 122 seconds.
> [ 247.181306] Not tainted 5.8.0-rc4-01456-gbfdfa51702de #815
> [ 247.184487] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
> [ 247.188876] cpumap/0/map:3 D 0 198 2 0x00004000
> [ 247.192624] Call Trace:
> [ 247.194327] __schedule+0x5ad/0xf10
> [ 247.196860] ? pci_mmcfg_check_reserved+0xd0/0xd0
> [ 247.199853] ? static_obj+0x31/0x80
> [ 247.201917] ? mark_held_locks+0x24/0x90
> [ 247.204398] ? cpu_map_update_elem+0x6d0/0x6d0
> [ 247.207098] schedule+0x6f/0x160
> [ 247.209079] schedule_preempt_disabled+0x14/0x20
> [ 247.211863] kthread+0x175/0x240
> [ 247.213698] ? kthread_create_on_node+0xd0/0xd0
> [ 247.216054] ret_from_fork+0x1f/0x30
> [ 247.218363]
> [ 247.218363] Showing all locks held in the system:
> [ 247.222150] 1 lock held by khungtaskd/33:
> [ 247.224894] #0: ffffffff82d246a0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x28/0x1c3
> [ 247.231113]
> [ 247.232335] =============================================
> [ 247.232335]
>
> qemu running with 4 vCPUs, 4 GB of memory. .config uploaded at
> https://paste.centos.org/view/0c14663d

ack, thx Jakub. I will look at it.

Regards,
Lorenzo

>
> HTH,
> -jkbs

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