Re: linux-next boot error: WARNING: workqueue cpumask: online intersect > possible intersect
From: Dmitry Vyukov
Date: Fri Jun 07 2019 - 04:50:11 EST
On Fri, Jun 7, 2019 at 10:33 AM syzbot
> syzbot found the following crash on:
> HEAD commit: ae3cad8f Add linux-next specific files for 20190603
> git tree: linux-next
> console output: https://syzkaller.appspot.com/x/log.txt?x=164f802ea00000
> kernel config: https://syzkaller.appspot.com/x/.config?x=7ccec0766d83706f
> dashboard link: https://syzkaller.appspot.com/bug?extid=4d497898effeb1936245
> compiler: gcc (GCC) 9.0.0 20181231 (experimental)
> Unfortunately, I don't have any reproducer for this crash yet.
> IMPORTANT: if you fix the bug, please add the following tag to the commit:
> Reported-by: syzbot+4d497898effeb1936245@xxxxxxxxxxxxxxxxxxxxxxxxx
> smpboot: CPU0: Intel(R) Xeon(R) CPU @ 2.30GHz (family: 0x6, model: 0x3f,
> stepping: 0x0)
> Performance Events: unsupported p6 CPU model 63 no PMU driver, software
> events only.
> rcu: Hierarchical SRCU implementation.
> NMI watchdog: Perf NMI watchdog permanently disabled
> smp: Bringing up secondary CPUs ...
> x86: Booting SMP configuration:
> .... node #0, CPUs: #1
> MDS CPU bug present and SMT on, data leak possible. See
> https://www.kernel.org/doc/html/latest/admin-guide/hw-vuln/mds.html for
> more details.
> smp: Brought up 2 nodes, 2 CPUs
> smpboot: Max logical packages: 1
> smpboot: Total of 2 processors activated (9200.00 BogoMIPS)
> devtmpfs: initialized
> clocksource: jiffies: mask: 0xffffffff max_cycles: 0xffffffff, max_idle_ns:
> 19112604462750000 ns
> futex hash table entries: 512 (order: 4, 65536 bytes)
> xor: automatically using best checksumming function avx
> PM: RTC time: 07:02:18, date: 2019-06-03
> NET: Registered protocol family 16
> audit: initializing netlink subsys (disabled)
> cpuidle: using governor menu
> ACPI: bus type PCI registered
> dca service started, version 1.12.1
> PCI: Using configuration type 1 for base access
> WARNING: workqueue cpumask: online intersect > possible intersect
+workqueue maintainers and Michael who added this WARNING
The WARNING was added in 2017, so I guess it's a change somewhere else
that triggered it.
The WARNING message does not seem to give enough info about the caller
(should it be changed to WARN_ONCE to print a stack?). How can be root
cause this and unbreak linux-next?
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