The patch titled Subject: mm/page_alloc: return 0 in case this node has no page within the zone has been added to the -mm tree. Its filename is mm-page_alloc-return-0-in-case-this-node-has-no-page-within-the-zone.patch This patch should soon appear at http://ozlabs.org/~akpm/mmots/broken-out/mm-page_alloc-return-0-in-case-this-node-has-no-page-within-the-zone.patch and later at http://ozlabs.org/~akpm/mmotm/broken-out/mm-page_alloc-return-0-in-case-this-node-has-no-page-within-the-zone.patch Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/SubmitChecklist when testing your code *** The -mm tree is included into linux-next and is updated there every 3-4 working days ------------------------------------------------------ From: Wei Yang <richard.weiyang@xxxxxxxxx> Subject: mm/page_alloc: return 0 in case this node has no page within the zone The whole memory space is divided into several zones and nodes may have no page in some zones. In this case, the __absent_pages_in_range() would return 0, since the range it is searching for is an empty range. Also this happens more often to those nodes with higher memory range when there are more nodes, which is a trend for future architectures. This patch checks the zone range after clamp and adjustment, return 0 if the range is an empty range. Link: http://lkml.kernel.org/r/20170206154314.15705-1-richard.weiyang@xxxxxxxxx Signed-off-by: Wei Yang <richard.weiyang@xxxxxxxxx> Cc: Vlastimil Babka <vbabka@xxxxxxx> Cc: Mel Gorman <mgorman@xxxxxxxxxxxxxxxxxxx> Cc: Michal Hocko <mhocko@xxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- mm/page_alloc.c | 5 +++++ 1 file changed, 5 insertions(+) diff -puN mm/page_alloc.c~mm-page_alloc-return-0-in-case-this-node-has-no-page-within-the-zone mm/page_alloc.c --- a/mm/page_alloc.c~mm-page_alloc-return-0-in-case-this-node-has-no-page-within-the-zone +++ a/mm/page_alloc.c @@ -5730,6 +5730,11 @@ static unsigned long __meminit zone_abse adjust_zone_range_for_zone_movable(nid, zone_type, node_start_pfn, node_end_pfn, &zone_start_pfn, &zone_end_pfn); + + /* If this node has no page within this zone, return 0. */ + if (zone_start_pfn == zone_end_pfn) + return 0; + nr_absent = __absent_pages_in_range(nid, zone_start_pfn, zone_end_pfn); /* _ Patches currently in -mm which might be from richard.weiyang@xxxxxxxxx are mm-memblockc-trivial-code-refine-in-memblock_is_region_memory.patch mm-memblockc-check-return-value-of-memblock_reserve-in-memblock_virt_alloc_internal.patch mm-page_alloc-return-0-in-case-this-node-has-no-page-within-the-zone.patch -- To unsubscribe from this list: send the line "unsubscribe mm-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html