On Tue, Sep 20, 2016 at 11:46:35AM -0700, David Daney wrote: > From: David Daney <david.da...@cavium.com> > > The wq_numa_init() function makes a private CPU to node map by calling > cpu_to_node() early in the boot process, before the non-boot CPUs are > brought online. Since the default implementation of cpu_to_node() > returns zero for CPUs that have never been brought online, the > workqueue system's view is that *all* CPUs are on node zero. > > When the unbound workqueue for a non-zero node is created, the > tsk_cpus_allowed() for the worker threads is the empty set because > there are, in the view of the workqueue system, no CPUs on non-zero > nodes. The code in try_to_wake_up() using this empty cpumask ends up > using the cpumask empty set value of NR_CPUS as an index into the > per-CPU area pointer array, and gets garbage as it is one past the end > of the array. This results in:
Queued for 4.8. Thanks. -- Catalin