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=-9.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,UNPARSEABLE_RELAY, URIBL_BLOCKED,USER_AGENT_GIT 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 4523DC43387 for ; Thu, 3 Jan 2019 19:29:44 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 1A621217F5 for ; Thu, 3 Jan 2019 19:29:43 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727233AbfACT3m (ORCPT ); Thu, 3 Jan 2019 14:29:42 -0500 Received: from out30-133.freemail.mail.aliyun.com ([115.124.30.133]:35950 "EHLO out30-133.freemail.mail.aliyun.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726813AbfACT3m (ORCPT ); Thu, 3 Jan 2019 14:29:42 -0500 X-Alimail-AntiSpam: AC=PASS;BC=-1|-1;BR=01201311R701e4;CH=green;FP=0|-1|-1|-1|0|-1|-1|-1;HT=e01e04426;MF=yang.shi@linux.alibaba.com;NM=1;PH=DS;RN=8;SR=0;TI=SMTPD_---0THTEqVm_1546543673; Received: from e19h19392.et15sqa.tbsite.net(mailfrom:yang.shi@linux.alibaba.com fp:SMTPD_---0THTEqVm_1546543673) by smtp.aliyun-inc.com(127.0.0.1); Fri, 04 Jan 2019 03:28:01 +0800 From: Yang Shi To: ying.huang@intel.com, tim.c.chen@intel.com, minchan@kernel.org, daniel.m.jordan@oracle.com, akpm@linux-foundation.org Cc: yang.shi@linux.alibaba.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: [v5 PATCH 2/2] mm: swap: add comment for swap_vma_readahead Date: Fri, 4 Jan 2019 03:27:53 +0800 Message-Id: <1546543673-108536-2-git-send-email-yang.shi@linux.alibaba.com> X-Mailer: git-send-email 1.8.3.1 In-Reply-To: <1546543673-108536-1-git-send-email-yang.shi@linux.alibaba.com> References: <1546543673-108536-1-git-send-email-yang.shi@linux.alibaba.com> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org swap_vma_readahead()'s comment is missed, just add it. Cc: Huang Ying Cc: Tim Chen Cc: Minchan Kim Signed-off-by: Yang Shi --- v5: Fixed the comments per Ying Huang mm/swap_state.c | 16 +++++++++++++++- 1 file changed, 15 insertions(+), 1 deletion(-) diff --git a/mm/swap_state.c b/mm/swap_state.c index 78d500e..c8730d7 100644 --- a/mm/swap_state.c +++ b/mm/swap_state.c @@ -523,7 +523,7 @@ static unsigned long swapin_nr_pages(unsigned long offset) * This has been extended to use the NUMA policies from the mm triggering * the readahead. * - * Caller must hold down_read on the vma->vm_mm if vmf->vma is not NULL. + * Caller must hold read mmap_sem if vmf->vma is not NULL. */ struct page *swap_cluster_readahead(swp_entry_t entry, gfp_t gfp_mask, struct vm_fault *vmf) @@ -698,6 +698,20 @@ static void swap_ra_info(struct vm_fault *vmf, pte_unmap(orig_pte); } +/** + * swap_vma_readahead - swap in pages in hope we need them soon + * @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. + * + * Caller must hold read mmap_sem if vmf->vma is not NULL. + * + */ static struct page *swap_vma_readahead(swp_entry_t fentry, gfp_t gfp_mask, struct vm_fault *vmf) { -- 1.8.3.1