Messages in this thread | | | From | Vineeth Remanan Pillai <> | Date | Tue, 14 Apr 2020 17:35:07 -0400 | Subject | Re: [RFC PATCH 03/13] sched: Core-wide rq->lock |
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> Aside from the fact that it's probably much saner to write this as: > > rq->core_enabled = static_key_enabled(&__sched_core_enabled); > > I'm fairly sure I didn't write this part. And while I do somewhat see > the point of disabling core scheduling for a core that has only a single > thread on, I wonder why we care. > I think this change was to fix some crashes which happened due to uninitialized rq->core if a sibling was offline during boot and is onlined after coresched was enabled.
https://lwn.net/ml/linux-kernel/20190424111913.1386-1-vpillai@digitalocean.com/
I tried to fix it by initializing coresched members during a cpu online and tearing it down on a cpu offline. This was back in v3 and do not remember the exact details. I shall revisit this and see if there is a better way to fix the race condition above.
Thanks, Vineeth
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