Messages in this thread | | | Subject | Re: [PATCH] mm/memory_hotplug: Make unpopulated zones PCP structures unreachable during hot remove | From | David Hildenbrand <> | Date | Fri, 9 Apr 2021 21:05:25 +0200 |
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>>> zone_pcp_reset still needs to exist to drain the remaining vmstats or >>> it'll break 5a883813845a ("memory-hotplug: fix zone stat >>> mismatch"). >> >> Are you sure we are reseting vmstats in the hotremove. I do not see >> anything like that. Maybe this was needed at the time. I will double >> check. > > zone_pcp_reset calls drain_zonestat to apply the per-cpu vmstat deltas > to the atomic per-zone and global stats. > > If anything, the minimal "fix" is to simply delete IRQ disable/enable on > the grounds that IRQs protect nothing and assume the existing hotplug > paths guarantees the PCP cannot be used after zone_pcp_enable(). That
^ that sounds sane to me
> should be the case already because all the pages have been freed and > there is nothing to even put into the PCPs but I worried that the PCP > structure itself might still be reachable even if it's useless which is > why I freed the structure once they could not be reached via zonelists. >
-- Thanks,
David / dhildenb
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