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=-1.0 required=3.0 tests=MAILING_LIST_MULTI,SPF_PASS, UNPARSEABLE_RELAY 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 2B95CC43387 for ; Fri, 21 Dec 2018 18:54:40 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 005D621927 for ; Fri, 21 Dec 2018 18:54:39 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2389434AbeLUSyi (ORCPT ); Fri, 21 Dec 2018 13:54:38 -0500 Received: from out30-132.freemail.mail.aliyun.com ([115.124.30.132]:34376 "EHLO out30-132.freemail.mail.aliyun.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731021AbeLUSyi (ORCPT ); Fri, 21 Dec 2018 13:54:38 -0500 X-Alimail-AntiSpam: AC=PASS;BC=-1|-1;BR=01201311R481e4;CH=green;FP=0|-1|-1|-1|0|-1|-1|-1;HT=e01e07449;MF=yang.shi@linux.alibaba.com;NM=1;PH=DS;RN=7;SR=0;TI=SMTPD_---0TGL1Hog_1545418274; Received: from US-143344MP.local(mailfrom:yang.shi@linux.alibaba.com fp:SMTPD_---0TGL1Hog_1545418274) by smtp.aliyun-inc.com(127.0.0.1); Sat, 22 Dec 2018 02:51:17 +0800 Subject: Re: [v2 PATCH 1/2] mm: swap: check if swap backing device is congested or not To: Tim Chen , ying.huang@intel.com, tim.c.chen@intel.com, minchan@kernel.org, akpm@linux-foundation.org Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org References: <1545351679-23596-1-git-send-email-yang.shi@linux.alibaba.com> From: Yang Shi Message-ID: <6878473d-3d3a-bbab-e187-f618c17db044@linux.alibaba.com> Date: Fri, 21 Dec 2018 10:51:11 -0800 User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.12; rv:52.0) Gecko/20100101 Thunderbird/52.7.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Content-Language: en-US Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 12/21/18 10:34 AM, Tim Chen wrote: > On 12/20/18 4:21 PM, Yang Shi wrote: > >> --- a/mm/swap_state.c >> +++ b/mm/swap_state.c >> @@ -538,11 +538,17 @@ struct page *swap_cluster_readahead(swp_entry_t entry, gfp_t gfp_mask, >> bool do_poll = true, page_allocated; >> struct vm_area_struct *vma = vmf->vma; >> unsigned long addr = vmf->address; >> + struct inode *inode = si->swap_file->f_mapping->host; >> >> mask = swapin_nr_pages(offset) - 1; >> if (!mask) >> goto skip; >> >> + if (si->flags & (SWP_BLKDEV | SWP_FS)) { > Maybe move the inode dereference here: > > inode = si->swap_file->f_mapping->host; Yes, it looks better since nobody deference inode except the below code. Will fix in v3. Thanks, Yang > >> + if (inode_read_congested(inode)) >> + goto skip; >> + } >> + > Thanks. > > Tim