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=-6.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED autolearn=ham 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 2B8D8ECDE44 for ; Sun, 4 Nov 2018 22:13:16 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id F00E32081D for ; Sun, 4 Nov 2018 22:13:15 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org F00E32081D Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=virtuozzo.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730231AbeKEH3n (ORCPT ); Mon, 5 Nov 2018 02:29:43 -0500 Received: from relay.sw.ru ([185.231.240.75]:54608 "EHLO relay.sw.ru" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729223AbeKEH3m (ORCPT ); Mon, 5 Nov 2018 02:29:42 -0500 Received: from [172.16.24.21] by relay.sw.ru with esmtp (Exim 4.90_1) (envelope-from ) id 1gJQds-00063T-EZ; Mon, 05 Nov 2018 01:13:12 +0300 From: Vasily Averin Subject: [PATCH 2/2] mm: avoid unnecessary swap_info_struct allocation To: linux-mm@kvack.org, Andrew Morton Cc: Huang Ying , linux-kernel@vger.kernel.org, Aaron Lu Message-ID: Date: Mon, 5 Nov 2018 01:13:12 +0300 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.2.1 MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Currently newly allocated swap_info_struct can be quickly freed. This patch avoid uneccessary high-order page allocation and helps to decrease the memory pressure. Signed-off-by: Vasily Averin --- mm/swapfile.c | 18 +++++++++++++----- 1 file changed, 13 insertions(+), 5 deletions(-) diff --git a/mm/swapfile.c b/mm/swapfile.c index 8688ae65ef58..53ec2f0cdf26 100644 --- a/mm/swapfile.c +++ b/mm/swapfile.c @@ -2809,14 +2809,17 @@ late_initcall(max_swapfiles_check); static struct swap_info_struct *alloc_swap_info(void) { - struct swap_info_struct *p; + struct swap_info_struct *p = NULL; unsigned int type; int i; + bool force_alloc = false; - p = kvzalloc(sizeof(*p), GFP_KERNEL); - if (!p) - return ERR_PTR(-ENOMEM); - +retry: + if (force_alloc) { + p = kvzalloc(sizeof(*p), GFP_KERNEL); + if (!p) + return ERR_PTR(-ENOMEM); + } spin_lock(&swap_lock); for (type = 0; type < nr_swapfiles; type++) { if (!(swap_info[type]->flags & SWP_USED)) @@ -2828,6 +2831,11 @@ static struct swap_info_struct *alloc_swap_info(void) return ERR_PTR(-EPERM); } if (type >= nr_swapfiles) { + if (!force_alloc) { + force_alloc = true; + spin_unlock(&swap_lock); + goto retry; + } p->type = type; swap_info[type] = p; /* -- 2.17.1