The semantics of MPOL_PREFERRED_MANY is similar to MPOL_PREFERRED, that it will first try to allocate memory from the preferred node(s), and fallback to all nodes in system when first try fails. Add a dedicated function for it just like 'interleave' policy. Link: https://lore.kernel.org/r/20200630212517.308045-9-ben.widawsky@xxxxxxxxx Suggested-by: Michal Hocko <mhocko@xxxxxxxx> Co-developed-by: Ben Widawsky <ben.widawsky@xxxxxxxxx> Signed-off-by: Ben Widawsky <ben.widawsky@xxxxxxxxx> Signed-off-by: Feng Tang <feng.tang@xxxxxxxxx> --- mm/mempolicy.c | 19 +++++++++++++++++++ 1 file changed, 19 insertions(+) diff --git a/mm/mempolicy.c b/mm/mempolicy.c index 17b5800b7dcc..d17bf018efcc 100644 --- a/mm/mempolicy.c +++ b/mm/mempolicy.c @@ -2153,6 +2153,25 @@ static struct page *alloc_page_interleave(gfp_t gfp, unsigned order, return page; } +static struct page *alloc_page_preferred_many(gfp_t gfp, unsigned int order, + struct mempolicy *pol) +{ + struct page *page; + + /* + * This is a two pass approach. The first pass will only try the + * preferred nodes but skip the direct reclaim and allow the + * allocation to fail, while the second pass will try all the + * nodes in system. + */ + page = __alloc_pages(((gfp | __GFP_NOWARN) & ~__GFP_DIRECT_RECLAIM), + order, first_node(pol->nodes), &pol->nodes); + if (!page) + page = __alloc_pages(gfp, order, numa_node_id(), NULL); + + return page; +} + /** * alloc_pages_vma - Allocate a page for a VMA. * @gfp: GFP flags. -- 2.7.4
