Messages in this thread | | | Subject | Re: [PATCH v4 1/4] mm,page_alloc: Bail out earlier on -ENOMEM in alloc_contig_migrate_range | From | David Hildenbrand <> | Date | Mon, 15 Mar 2021 12:10:04 +0100 |
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On 10.03.21 16:08, Oscar Salvador wrote: > Currently, __alloc_contig_migrate_range can generate -EINTR, -ENOMEM or -EBUSY, > and report them down the chain. > The problem is that when migrate_pages() reports -ENOMEM, we keep going till we > exhaust all the try-attempts (5 at the moment) instead of bailing out. > > migrate_pages bails out right away on -ENOMEM because it is considered a fatal > error. Do the same here instead of keep going and retrying. > > Signed-off-by: Oscar Salvador <osalvador@suse.de> > --- > mm/page_alloc.c | 8 +++++++- > 1 file changed, 7 insertions(+), 1 deletion(-) > > diff --git a/mm/page_alloc.c b/mm/page_alloc.c > index 3e4b29ee2b1e..94467f1b85ff 100644 > --- a/mm/page_alloc.c > +++ b/mm/page_alloc.c > @@ -8484,7 +8484,7 @@ static int __alloc_contig_migrate_range(struct compact_control *cc, > } > tries = 0; > } else if (++tries == 5) { > - ret = ret < 0 ? ret : -EBUSY; > + ret = -EBUSY; > break; > } > > @@ -8494,6 +8494,12 @@ static int __alloc_contig_migrate_range(struct compact_control *cc, > > ret = migrate_pages(&cc->migratepages, alloc_migration_target, > NULL, (unsigned long)&mtc, cc->mode, MR_CONTIG_RANGE); > + /* > + * On -ENOMEM, migrate_pages() bails out right away. It is pointless > + * to retry again over this error, so do the same here. > + */ > + if (ret == -ENOMEM) > + break;
I would have thought we could also be able to get other fatal errors from migrate_pages(), but doesn't seem like it
Reviewed-by: David Hildenbrand <david@redhat.com>
-- Thanks,
David / dhildenb
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