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=-7.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,UNPARSEABLE_RELAY, 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 6451AC43387 for ; Thu, 3 Jan 2019 17:14:56 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 3C7522073D for ; Thu, 3 Jan 2019 17:14:56 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731693AbfACROz (ORCPT ); Thu, 3 Jan 2019 12:14:55 -0500 Received: from out30-131.freemail.mail.aliyun.com ([115.124.30.131]:52736 "EHLO out30-131.freemail.mail.aliyun.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731181AbfACROy (ORCPT ); Thu, 3 Jan 2019 12:14:54 -0500 X-Alimail-AntiSpam: AC=PASS;BC=-1|-1;BR=01201311R201e4;CH=green;FP=0|-1|-1|-1|0|-1|-1|-1;HT=e01e01424;MF=yang.shi@linux.alibaba.com;NM=1;PH=DS;RN=6;SR=0;TI=SMTPD_---0THSwDTY_1546535572; Received: from US-143344MP.local(mailfrom:yang.shi@linux.alibaba.com fp:SMTPD_---0THSwDTY_1546535572) by smtp.aliyun-inc.com(127.0.0.1); Fri, 04 Jan 2019 01:12:54 +0800 Subject: Re: [v4 PATCH 2/2] mm: swap: add comment for swap_vma_readahead To: "Huang, Ying" Cc: tim.c.chen@intel.com, minchan@kernel.org, akpm@linux-foundation.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org References: <1546145375-793-1-git-send-email-yang.shi@linux.alibaba.com> <1546145375-793-2-git-send-email-yang.shi@linux.alibaba.com> <875zv6w5m6.fsf@yhuang-dev.intel.com> From: Yang Shi Message-ID: Date: Thu, 3 Jan 2019 09:12:52 -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: <875zv6w5m6.fsf@yhuang-dev.intel.com> Content-Type: text/plain; charset=windows-1252; 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 1/2/19 11:41 PM, Huang, Ying wrote: > Yang Shi writes: > >> swap_vma_readahead()'s comment is missed, just add it. >> >> Cc: Huang Ying >> Cc: Tim Chen >> Cc: Minchan Kim >> Signed-off-by: Yang Shi >> --- >> mm/swap_state.c | 17 +++++++++++++++++ >> 1 file changed, 17 insertions(+) >> >> diff --git a/mm/swap_state.c b/mm/swap_state.c >> index 78d500e..dd8f698 100644 >> --- a/mm/swap_state.c >> +++ b/mm/swap_state.c >> @@ -698,6 +698,23 @@ static void swap_ra_info(struct vm_fault *vmf, >> pte_unmap(orig_pte); >> } >> >> +/** >> + * swap_vm_readahead - swap in pages in hope we need them soon > s/swap_vm_readahead/swap_vma_readahead/ > >> + * @entry: swap entry of this memory >> + * @gfp_mask: memory allocation flags >> + * @vmf: fault information >> + * >> + * Returns the struct page for entry and addr, after queueing swapin. >> + * >> + * Primitive swap readahead code. We simply read in a few pages whoes >> + * virtual addresses are around the fault address in the same vma. >> + * >> + * This has been extended to use the NUMA policies from the mm triggering >> + * the readahead. > What is this? I know you copy it from swap_cluster_readahead(), but we > have only one mm for vma readahead. Aha, I see. Actually I was confused by this too, so just copied from swap_cluster_readahead. > >> + * Caller must hold down_read on the vma->vm_mm if vmf->vma is not NULL. > Better to make it explicit that your are talking about mmap_sem? Sure. Thanks, Yang > > Best Regards, > Huang, Ying > >> + * >> + */ >> static struct page *swap_vma_readahead(swp_entry_t fentry, gfp_t gfp_mask, >> struct vm_fault *vmf) >> {