From: Joonsoo Kim <iamjoonsoo.kim@xxxxxxx> Subject: mm/hugetlb: add same zone check in pfn_range_valid_gigantic() This patchset deals with some problematic sites that iterate pfn ranges. There is a system thats node's pfns are overlapped as follows: -----pfn--------> N0 N1 N2 N0 N1 N2 Therefore, we need to take care of this overlapping when iterating pfn range. I audit many iterating sites that uses pfn_valid(), pfn_valid_within(), zone_start_pfn and etc. and others looks safe to me. This is a preparation step for a new CMA implementation, ZONE_CMA (https://lkml.org/lkml/2015/2/12/95), because it would be easily overlapped with other zones. But, zone overlap check is also needed for the general case so I send it separately. This patch (of 5): alloc_gigantic_page() uses alloc_contig_range() and this requires that the requested range is in a single zone. To satisfy this requirement, add this check to pfn_range_valid_gigantic(). Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@xxxxxxx> Acked-by: Vlastimil Babka <vbabka@xxxxxxx> Cc: Rik van Riel <riel@xxxxxxxxxx> Cc: Johannes Weiner <hannes@xxxxxxxxxxx> Cc: Mel Gorman <mgorman@xxxxxxxxxxxxxxxxxxx> Cc: Laura Abbott <lauraa@xxxxxxxxxxxxxx> Cc: Minchan Kim <minchan@xxxxxxxxxx> Cc: Marek Szyprowski <m.szyprowski@xxxxxxxxxxx> Cc: Michal Nazarewicz <mina86@xxxxxxxxxx> Cc: "Aneesh Kumar K.V" <aneesh.kumar@xxxxxxxxxxxxxxxxxx> Cc: "Rafael J. Wysocki" <rjw@xxxxxxxxxxxxx> Cc: Benjamin Herrenschmidt <benh@xxxxxxxxxxxxxxxxxxx> Cc: Paul Mackerras <paulus@xxxxxxxxx> Cc: Michael Ellerman <mpe@xxxxxxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- mm/hugetlb.c | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-) diff -puN mm/hugetlb.c~mm-hugetlb-add-same-zone-check-in-pfn_range_valid_gigantic mm/hugetlb.c --- a/mm/hugetlb.c~mm-hugetlb-add-same-zone-check-in-pfn_range_valid_gigantic +++ a/mm/hugetlb.c @@ -1031,8 +1031,8 @@ static int __alloc_gigantic_page(unsigne return alloc_contig_range(start_pfn, end_pfn, MIGRATE_MOVABLE); } -static bool pfn_range_valid_gigantic(unsigned long start_pfn, - unsigned long nr_pages) +static bool pfn_range_valid_gigantic(struct zone *z, + unsigned long start_pfn, unsigned long nr_pages) { unsigned long i, end_pfn = start_pfn + nr_pages; struct page *page; @@ -1043,6 +1043,9 @@ static bool pfn_range_valid_gigantic(uns page = pfn_to_page(i); + if (page_zone(page) != z) + return false; + if (PageReserved(page)) return false; @@ -1075,7 +1078,7 @@ static struct page *alloc_gigantic_page( pfn = ALIGN(z->zone_start_pfn, nr_pages); while (zone_spans_last_pfn(z, pfn, nr_pages)) { - if (pfn_range_valid_gigantic(pfn, nr_pages)) { + if (pfn_range_valid_gigantic(z, pfn, nr_pages)) { /* * We release the zone lock here because * alloc_contig_range() will also lock the zone _ -- 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
