From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-10.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 85724C282C3 for ; Thu, 24 Jan 2019 19:53:34 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 54AEB217D4 for ; Thu, 24 Jan 2019 19:53:34 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1548359614; bh=7wKc/LdAtcw7xzvn5r8WuIfJ+u7vGGt+s5u5Mg1trv8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=R546qUB3tjEdIPzo9bxR5WVN5Dy/9MMnAAQskBs4Fuomnow8dEisZmdCySe30O/lG FUegEhiv1e9U+Wvsfo7YrZC/mHWYN0QNChqP2skEe1cnVv5NjkyyBYOSYCc+A3U+M9 Wqb+MUXbqhFczQwkpm5R/tlWxfPPoy0NqH0VTbus= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732010AbfAXTiN (ORCPT ); Thu, 24 Jan 2019 14:38:13 -0500 Received: from mail.kernel.org ([198.145.29.99]:38380 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731334AbfAXTiM (ORCPT ); Thu, 24 Jan 2019 14:38:12 -0500 Received: from localhost (5356596B.cm-6-7b.dynamic.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id D0C89218FC; Thu, 24 Jan 2019 19:38:10 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1548358691; bh=7wKc/LdAtcw7xzvn5r8WuIfJ+u7vGGt+s5u5Mg1trv8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=ErjonseoFBvUpSB6XnWhDaEqVpcKXlfFYWbMmvxE6YEO9ZthW5htUa3xzV1ZhEnis RAV0jBPG4nhZYhNnKrtqlvEq0aj0A56yV8FqOAspNOYx2etvsKW4a6zYXzvRzO/rcW +dgEg4G6CfCFwHXDe/3zM47Ph4hJ3vnbVRZpGFLo= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Aaron Lu , Andrew Morton , Michal Hocko , Vasily Averin , Huang Ying , Linus Torvalds , Sasha Levin Subject: [PATCH 4.19 097/106] mm/swap: use nr_node_ids for avail_lists in swap_info_struct Date: Thu, 24 Jan 2019 20:20:54 +0100 Message-Id: <20190124190212.131462514@linuxfoundation.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190124190206.342411005@linuxfoundation.org> References: <20190124190206.342411005@linuxfoundation.org> User-Agent: quilt/0.65 X-stable: review X-Patchwork-Hint: ignore MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org 4.19-stable review patch. If anyone has any objections, please let me know. ------------------ [ Upstream commit 66f71da9dd38af17dc17209cdde7987d4679a699 ] Since a2468cc9bfdf ("swap: choose swap device according to numa node"), avail_lists field of swap_info_struct is changed to an array with MAX_NUMNODES elements. This made swap_info_struct size increased to 40KiB and needs an order-4 page to hold it. This is not optimal in that: 1 Most systems have way less than MAX_NUMNODES(1024) nodes so it is a waste of memory; 2 It could cause swapon failure if the swap device is swapped on after system has been running for a while, due to no order-4 page is available as pointed out by Vasily Averin. Solve the above two issues by using nr_node_ids(which is the actual possible node number the running system has) for avail_lists instead of MAX_NUMNODES. nr_node_ids is unknown at compile time so can't be directly used when declaring this array. What I did here is to declare avail_lists as zero element array and allocate space for it when allocating space for swap_info_struct. The reason why keep using array but not pointer is plist_for_each_entry needs the field to be part of the struct, so pointer will not work. This patch is on top of Vasily Averin's fix commit. I think the use of kvzalloc for swap_info_struct is still needed in case nr_node_ids is really big on some systems. Link: http://lkml.kernel.org/r/20181115083847.GA11129@intel.com Signed-off-by: Aaron Lu Reviewed-by: Andrew Morton Acked-by: Michal Hocko Cc: Vasily Averin Cc: Huang Ying Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Sasha Levin --- include/linux/swap.h | 11 ++++++++++- mm/swapfile.c | 3 ++- 2 files changed, 12 insertions(+), 2 deletions(-) diff --git a/include/linux/swap.h b/include/linux/swap.h index 8e2c11e692ba..77221c16733a 100644 --- a/include/linux/swap.h +++ b/include/linux/swap.h @@ -232,7 +232,6 @@ struct swap_info_struct { unsigned long flags; /* SWP_USED etc: see above */ signed short prio; /* swap priority of this type */ struct plist_node list; /* entry in swap_active_head */ - struct plist_node avail_lists[MAX_NUMNODES];/* entry in swap_avail_heads */ signed char type; /* strange name for an index */ unsigned int max; /* extent of the swap_map */ unsigned char *swap_map; /* vmalloc'ed array of usage counts */ @@ -273,6 +272,16 @@ struct swap_info_struct { */ struct work_struct discard_work; /* discard worker */ struct swap_cluster_list discard_clusters; /* discard clusters list */ + struct plist_node avail_lists[0]; /* + * entries in swap_avail_heads, one + * entry per node. + * Must be last as the number of the + * array is nr_node_ids, which is not + * a fixed value so have to allocate + * dynamically. + * And it has to be an array so that + * plist_for_each_* can work. + */ }; #ifdef CONFIG_64BIT diff --git a/mm/swapfile.c b/mm/swapfile.c index 67aaf7ae22ff..340ef3177686 100644 --- a/mm/swapfile.c +++ b/mm/swapfile.c @@ -2820,8 +2820,9 @@ static struct swap_info_struct *alloc_swap_info(void) struct swap_info_struct *p; unsigned int type; int i; + int size = sizeof(*p) + nr_node_ids * sizeof(struct plist_node); - p = kvzalloc(sizeof(*p), GFP_KERNEL); + p = kvzalloc(size, GFP_KERNEL); if (!p) return ERR_PTR(-ENOMEM); -- 2.19.1