Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753168AbbDXKSG (ORCPT ); Fri, 24 Apr 2015 06:18:06 -0400 Received: from cn.fujitsu.com ([59.151.112.132]:18277 "EHLO heian.cn.fujitsu.com" rhost-flags-OK-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S1752668AbbDXKRx (ORCPT ); Fri, 24 Apr 2015 06:17:53 -0400 X-IronPort-AV: E=Sophos;i="5.04,848,1406563200"; d="scan'208";a="91182296" From: Gu Zheng To: CC: , , , , , , , , , , , , Subject: [RESEND RFC PATCH 2/2] gfp: use the best near online node if the target node is offline Date: Fri, 24 Apr 2015 17:58:33 +0800 Message-ID: <1429869513-2906-2-git-send-email-guz.fnst@cn.fujitsu.com> X-Mailer: git-send-email 1.7.7 In-Reply-To: <1429869513-2906-1-git-send-email-guz.fnst@cn.fujitsu.com> References: <1429869513-2906-1-git-send-email-guz.fnst@cn.fujitsu.com> MIME-Version: 1.0 Content-Type: text/plain X-Originating-IP: [10.167.226.100] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2001 Lines: 67 Since the change to the cpu <--> mapping (map the cpu to the physical node for all possible at the boot), the node of cpu may be not present, so we use the best near online node if the node is not present in the low level allocation APIs. Signed-off-by: Gu Zheng --- include/linux/gfp.h | 28 +++++++++++++++++++++++++++- 1 files changed, 27 insertions(+), 1 deletions(-) diff --git a/include/linux/gfp.h b/include/linux/gfp.h index 97a9373..19684a8 100644 --- a/include/linux/gfp.h +++ b/include/linux/gfp.h @@ -298,9 +298,31 @@ __alloc_pages(gfp_t gfp_mask, unsigned int order, return __alloc_pages_nodemask(gfp_mask, order, zonelist, NULL); } +static int find_near_online_node(int node) +{ + int n, val; + int min_val = INT_MAX; + int best_node = -1; + + for_each_online_node(n) { + val = node_distance(node, n); + + if (val < min_val) { + min_val = val; + best_node = n; + } + } + + return best_node; +} + static inline struct page *alloc_pages_node(int nid, gfp_t gfp_mask, unsigned int order) { + /* Offline node, use the best near online node */ + if (!node_online(nid)) + nid = find_near_online_node(nid); + /* Unknown node is current node */ if (nid < 0) nid = numa_node_id(); @@ -311,7 +333,11 @@ static inline struct page *alloc_pages_node(int nid, gfp_t gfp_mask, static inline struct page *alloc_pages_exact_node(int nid, gfp_t gfp_mask, unsigned int order) { - VM_BUG_ON(nid < 0 || nid >= MAX_NUMNODES || !node_online(nid)); + /* Offline node, use the best near online node */ + if (!node_online(nid)) + nid = find_near_online_node(nid); + + VM_BUG_ON(nid < 0 || nid >= MAX_NUMNODES); return __alloc_pages(gfp_mask, order, node_zonelist(nid, gfp_mask)); } -- 1.7.7 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/