Messages in this thread | | | Date | Fri, 11 Dec 2020 13:16:38 +0000 | From | Vincent Donnefort <> | Subject | Re: [PATCH 2/2] workqueue: Fix affinity of kworkers attached during late hotplug |
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On Fri, Dec 11, 2020 at 01:13:35PM +0000, Valentin Schneider wrote: > On 11/12/20 12:51, Valentin Schneider wrote: > >> In that case maybe we should check for the cpu_active_mask here too ? > > > > Looking at it again, I think we might need to. > > > > IIUC you can end up with pools bound to a single NUMA node (?). In that > > case, say the last CPU of a node is going down, then: > > > > workqueue_offline_cpu() > > wq_update_unbound_numa() > > alloc_unbound_pwq() > > get_unbound_pool() > > > > would still pick that node, because it doesn't look at the online / active > > mask. And at this point, we would affine the > > kworkers to that node, and we're back to having kworkers enqueued on a > > (!active, online) CPU that is going down... > > Assuming a node covers at least 2 CPUs, that can't actually happen per > is_cpu_allowed().
Yes indeed, my bad, no problem here.
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