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 Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id 0ABFCC433EF for ; Thu, 21 Apr 2022 00:44:41 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 477B06B0071; Wed, 20 Apr 2022 20:44:41 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 425936B0073; Wed, 20 Apr 2022 20:44:41 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 2C6876B0074; Wed, 20 Apr 2022 20:44:41 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (relay.hostedemail.com [64.99.140.27]) by kanga.kvack.org (Postfix) with ESMTP id 1A8F76B0071 for ; Wed, 20 Apr 2022 20:44:41 -0400 (EDT) Received: from smtpin21.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay08.hostedemail.com (Postfix) with ESMTP id DC38821B05 for ; Thu, 21 Apr 2022 00:44:40 +0000 (UTC) X-FDA: 79379040720.21.289583C Received: from mail-pj1-f51.google.com (mail-pj1-f51.google.com [209.85.216.51]) by imf06.hostedemail.com (Postfix) with ESMTP id A2A54180024 for ; Thu, 21 Apr 2022 00:44:39 +0000 (UTC) Received: by mail-pj1-f51.google.com with SMTP id z5-20020a17090a468500b001d2bc2743c4so3679287pjf.0 for ; Wed, 20 Apr 2022 17:44:40 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=ESUxm4cSJyIm60549ToiEcMf0F7V0X1uPD4V4iCHr1g=; b=iCLZwnUrJlXXS94NHeOiMqZdbp79cqEIAIkcxS3f1QhYmIU4Rn72icr+yGFMXL7sJq wgPHBQcOdAxXOBEeXSWFmZ5+2+zhjQ3yYKyOCdd+LxjNIetmHSlz804tJPwbjm2t3CVd i0t77FIu70AC9aRHobJ3ZLFq5TlHMCcTw2lxEXzjLpQ15yj7ycOSvanS6K0fwndiEz0m fSlFP1OiPDmc80jD/DnJ4kPukwewQQPrzxhPUvTYAn+nTvjAwv6Sn/2ylRCR90Hn7gD3 FkxAg8MQH+lKjgDSJjoGIuqOfCZdVn7DMkDD9l2BZCVW6MgZZuzAX2gBwXuMwb1mNkau LLow== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=ESUxm4cSJyIm60549ToiEcMf0F7V0X1uPD4V4iCHr1g=; b=w8ky0vyx4nozWnR5oUy3R4ugftqEaa9LLbe/TOQKY0ysoTNgbZAGhVu6+SMVvShmXs sOOhedgtIraVUKI3MISX3UL22cmkFBPiAGfTVZhysLcTkiHZQuprSn/XmTTFfAss+ea5 nyfz7eGOBdvT/9qjoM8iz7RwFH/5bjdAMg//4uDa0zbYw4ReLf/wGWE55F8hoEJz5ytQ kgAr2ghISjR0YZ2bYcmptj8HtuhCja5f8De38FeZskO9RvHU0FmEYlbK9mVQmnnCGcFp K+W1KLOom8OmX3VZRwCipppLwxz7bYdfJ//3rN2tDfo7V5Y8VEKjicEtWdbbk2D9Xz8W moYA== X-Gm-Message-State: AOAM533dNbQPf8lbnh2hx3+OyYXjLqD8PomT/ClHEsd1Gueb1yMjZ+Zt 7Xrb3pNWCUThOsig9bcfcMri8QfMerTN8I0Lf3E= X-Google-Smtp-Source: ABdhPJziSwrhCSrYNTJmBFaWn3ITBCiVgMnq0qlf+ROQeo46KkFucBE9DDNvi7wGYLxJk3HuGVoiZKZmDBQxznThA90= X-Received: by 2002:a17:90b:4b10:b0:1d2:c235:6c8e with SMTP id lx16-20020a17090b4b1000b001d2c2356c8emr7292583pjb.21.1650501879483; Wed, 20 Apr 2022 17:44:39 -0700 (PDT) MIME-Version: 1.0 References: <20220419122234.45083-1-linmiaohe@huawei.com> In-Reply-To: <20220419122234.45083-1-linmiaohe@huawei.com> From: Yang Shi Date: Wed, 20 Apr 2022 17:44:27 -0700 Message-ID: Subject: Re: [PATCH] mm/mempolicy: clean up the code logic in queue_pages_pte_range To: Miaohe Lin Cc: Andrew Morton , Linux MM , Linux Kernel Mailing List Content-Type: text/plain; charset="UTF-8" X-Stat-Signature: uigcdoapcycbtwyo6sfgkdizx1no6pww X-Rspam-User: Authentication-Results: imf06.hostedemail.com; dkim=pass header.d=gmail.com header.s=20210112 header.b=iCLZwnUr; dmarc=pass (policy=none) header.from=gmail.com; spf=pass (imf06.hostedemail.com: domain of shy828301@gmail.com designates 209.85.216.51 as permitted sender) smtp.mailfrom=shy828301@gmail.com X-Rspamd-Server: rspam02 X-Rspamd-Queue-Id: A2A54180024 X-HE-Tag: 1650501879-764484 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Tue, Apr 19, 2022 at 5:22 AM Miaohe Lin wrote: > > Since commit e5947d23edd8 ("mm: mempolicy: don't have to split pmd for > huge zero page"), THP is never splited in queue_pages_pmd. Thus 2 is > never returned now. We can remove such unnecessary ret != 2 check and > clean up the relevant comment. Minor improvements in readability. Nice catch. Yeah, it was missed when I worked on that commit. Reviewed-by: Yang Shi > > Signed-off-by: Miaohe Lin > --- > mm/mempolicy.c | 12 +++--------- > 1 file changed, 3 insertions(+), 9 deletions(-) > > diff --git a/mm/mempolicy.c b/mm/mempolicy.c > index 75a8b247f631..3934476fb708 100644 > --- a/mm/mempolicy.c > +++ b/mm/mempolicy.c > @@ -441,12 +441,11 @@ static inline bool queue_pages_required(struct page *page, > } > > /* > - * queue_pages_pmd() has four possible return values: > + * queue_pages_pmd() has three possible return values: > * 0 - pages are placed on the right node or queued successfully, or > * special page is met, i.e. huge zero page. > * 1 - there is unmovable page, and MPOL_MF_MOVE* & MPOL_MF_STRICT were > * specified. > - * 2 - THP was split. > * -EIO - is migration entry or only MPOL_MF_STRICT was specified and an > * existing page was already on a node that does not follow the > * policy. > @@ -508,18 +507,13 @@ static int queue_pages_pte_range(pmd_t *pmd, unsigned long addr, > struct page *page; > struct queue_pages *qp = walk->private; > unsigned long flags = qp->flags; > - int ret; > bool has_unmovable = false; > pte_t *pte, *mapped_pte; > spinlock_t *ptl; > > ptl = pmd_trans_huge_lock(pmd, vma); > - if (ptl) { > - ret = queue_pages_pmd(pmd, ptl, addr, end, walk); > - if (ret != 2) > - return ret; > - } > - /* THP was split, fall through to pte walk */ > + if (ptl) > + return queue_pages_pmd(pmd, ptl, addr, end, walk); > > if (pmd_trans_unstable(pmd)) > return 0; > -- > 2.23.0 > >