From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andi Kleen References: <20080317258.659191058@firstfloor.org> In-Reply-To: <20080317258.659191058@firstfloor.org> Subject: [PATCH] [7/18] Abstract out the NUMA node round robin code into a separate function Message-Id: <20080317015820.ECC861B41E0@basil.firstfloor.org> Date: Mon, 17 Mar 2008 02:58:20 +0100 (CET) Sender: owner-linux-mm@kvack.org Return-Path: To: linux-kernel@vger.kernel.org, pj@sgi.com, linux-mm@kvack.org, nickpiggin@yahoo.com.au List-ID: Need this as a separate function for a future patch. No behaviour change. Signed-off-by: Andi Kleen --- mm/hugetlb.c | 37 ++++++++++++++++++++++--------------- 1 file changed, 22 insertions(+), 15 deletions(-) Index: linux/mm/hugetlb.c =================================================================== --- linux.orig/mm/hugetlb.c +++ linux/mm/hugetlb.c @@ -219,6 +219,27 @@ static struct page *alloc_fresh_huge_pag return page; } +/* + * Use a helper variable to find the next node and then + * copy it back to hugetlb_next_nid afterwards: + * otherwise there's a window in which a racer might + * pass invalid nid MAX_NUMNODES to alloc_pages_node. + * But we don't need to use a spin_lock here: it really + * doesn't matter if occasionally a racer chooses the + * same nid as we do. Move nid forward in the mask even + * if we just successfully allocated a hugepage so that + * the next caller gets hugepages on the next node. + */ +static int huge_next_node(struct hstate *h) +{ + int next_nid; + next_nid = next_node(h->hugetlb_next_nid, node_online_map); + if (next_nid == MAX_NUMNODES) + next_nid = first_node(node_online_map); + h->hugetlb_next_nid = next_nid; + return next_nid; +} + static int alloc_fresh_huge_page(struct hstate *h) { struct page *page; @@ -232,21 +253,7 @@ static int alloc_fresh_huge_page(struct page = alloc_fresh_huge_page_node(h, h->hugetlb_next_nid); if (page) ret = 1; - /* - * Use a helper variable to find the next node and then - * copy it back to hugetlb_next_nid afterwards: - * otherwise there's a window in which a racer might - * pass invalid nid MAX_NUMNODES to alloc_pages_node. - * But we don't need to use a spin_lock here: it really - * doesn't matter if occasionally a racer chooses the - * same nid as we do. Move nid forward in the mask even - * if we just successfully allocated a hugepage so that - * the next caller gets hugepages on the next node. - */ - next_nid = next_node(h->hugetlb_next_nid, node_online_map); - if (next_nid == MAX_NUMNODES) - next_nid = first_node(node_online_map); - h->hugetlb_next_nid = next_nid; + next_nid = huge_next_node(h); } while (!page && h->hugetlb_next_nid != start_nid); return ret; -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org