Messages in this thread | | | From | SeongJae Park <> | Subject | Re: [PATCH] mm/memory_hotplug: return zero from do_migrate_range() for only success | Date | Wed, 15 Feb 2023 18:03:16 +0000 |
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On Wed, 15 Feb 2023 14:16:05 +0100 David Hildenbrand <david@redhat.com> wrote:
> On 14.02.23 23:32, SeongJae Park wrote: > > do_migrate_range() returns migrate_pages() return value, which zero > > means perfect success, in usual cases. If all pages are failed to be > > isolated, however, it returns isolate_{lru,movalbe}_page() return > > values, or zero if all pfn were invalid, were hugetlb or hwpoisoned. So > > do_migrate_range() returning zero means either perfect success, or > > special cases of isolation total failure. > > > > Actually, the return value is not checked by any caller, so it might be > > better to simply make it a void function. However, there is a TODO for > > checking the return value. > > I'd prefer to not add more dead code ;) Let's not return an error instead.
Makes sense, I will send next spin soon.
> > It's still unclear which kind of fatal migration issues we actually care > about and how to really detect them.
What do you think about treating the isolation/migration rate limit (migrate_rs) hit in do_migrate_range() as fatal? It warns for the event already, so definitely a bad sign.
If that's not that bad enough to be treated as fatal, I think we could have yet another rate limit to be considered fatal.
Thanks, SJ
> > -- > Thanks, > > David / dhildenb
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