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 AD177C433EF for ; Fri, 21 Jan 2022 22:26:21 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id DC6856B0080; Fri, 21 Jan 2022 17:26:20 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id D75486B0083; Fri, 21 Jan 2022 17:26:20 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id C64696B0085; Fri, 21 Jan 2022 17:26:20 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0049.hostedemail.com [216.40.44.49]) by kanga.kvack.org (Postfix) with ESMTP id BA3F36B0080 for ; Fri, 21 Jan 2022 17:26:20 -0500 (EST) Received: from smtpin07.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay01.hostedemail.com (Postfix) with ESMTP id 7893C181CAED6 for ; Fri, 21 Jan 2022 22:26:20 +0000 (UTC) X-FDA: 79055728920.07.CC8F6BD Received: from mail-yb1-f180.google.com (mail-yb1-f180.google.com [209.85.219.180]) by imf13.hostedemail.com (Postfix) with ESMTP id 6C7E620003 for ; Fri, 21 Jan 2022 22:26:19 +0000 (UTC) Received: by mail-yb1-f180.google.com with SMTP id k31so29954002ybj.4 for ; Fri, 21 Jan 2022 14:26:19 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=bytedance-com.20210112.gappssmtp.com; s=20210112; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=+TKDaf4r0DbwVoPKUnbWMT12wXKfJ7AIRMgW3bK94bA=; b=kdExy7G0SbxV21jH79dDAEh5+1datmVn6VmRcSrAEYVxiryK99n7j9b7BhtmEKoErn G9LLBCCltUndr/WMjVMIed9yYxGnRzSXWFSpEB7FhhPm7lqOt3YQjrezkSZm8s/d8wfu DnvrJv1aEGlp/tpDO0q4FOBhdmUiG6wGLp1Cgkk7pCpkOlApiEOEgVGLhV+LQo6bBxUo hqHjhXQMvaLxVIvlQBgNFu/bHxRIRhK6UKtYXkwal6FbjTlqG5mEBq4vqHeHBVb6338V dP6cjBnVWhgYeZMMhNWicv1WjeyVWHf+iDgijwQVfeKx08q/FQTrGkBvRdAHkSKOYdFY AYog== 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=+TKDaf4r0DbwVoPKUnbWMT12wXKfJ7AIRMgW3bK94bA=; b=4/ip3Bv5ulTvL9jlWCrwGHIJfWGKOrinofwUYTtQcsjkn86SuTCb9cu7icZRftKRqW 6aOsYgtg0ZRnDIb5Iuse/6SqXxP788HktejkNrPkwVonjdLR8zypg6tCJ9tD+Aw5u63f epsaQxpQFb1O9hpziNKGtxseVHeAd5PKHpw4WjPVuSEWvKCYMCVQHomBwnL4yI6F/yhj EBZTl3y1I4FQ4n0p1wRhx6Q8XB3C74Gg9kijvAie24uJKhaLAo4nQVOhuRBnZpT2/F6e WN0iO18JDK+IRDMXODZmFXQMz+jjl701cJpIZ6EPS9zLJYMXCAeA3Zsy87OZN3u2vo2l xyOw== X-Gm-Message-State: AOAM5327iFVA8OxcVPAXBaG/UMddRd2XhWeD61yBmb6dLGgV52p8dZBO lUpFqG/7a7Ndyo72VmlNXtP48yCOG3NrakbKvEpqVg== X-Google-Smtp-Source: ABdhPJxRFn5ZekQOhx4nZKJBlN2Az1DlK7aL494Zca3ycZLruWyMnjurc2t8qDev38vW3ezBDQHjUEgbncSep805xkw= X-Received: by 2002:a25:d107:: with SMTP id i7mr8790772ybg.495.1642803978431; Fri, 21 Jan 2022 14:26:18 -0800 (PST) MIME-Version: 1.0 References: <20220121081345.80320-1-songmuchun@bytedance.com> <20220121081345.80320-2-songmuchun@bytedance.com> <80208467-D04B-4215-9C5A-8BDBDB365853@nvidia.com> In-Reply-To: <80208467-D04B-4215-9C5A-8BDBDB365853@nvidia.com> From: Muchun Song Date: Sat, 22 Jan 2022 06:25:40 +0800 Message-ID: Subject: Re: [PATCH 2/2] mm: fix missing cache flush for all tail pages of THP To: Zi Yan Cc: Andrew Morton , "Kirill A. Shutemov" , Linux Memory Management List , LKML Content-Type: text/plain; charset="UTF-8" X-Rspamd-Server: rspam04 X-Rspamd-Queue-Id: 6C7E620003 X-Stat-Signature: a6y8ccwuyu9a9fecrjxn5upry38bd657 Authentication-Results: imf13.hostedemail.com; dkim=pass header.d=bytedance-com.20210112.gappssmtp.com header.s=20210112 header.b=kdExy7G0; spf=pass (imf13.hostedemail.com: domain of songmuchun@bytedance.com designates 209.85.219.180 as permitted sender) smtp.mailfrom=songmuchun@bytedance.com; dmarc=pass (policy=none) header.from=bytedance.com X-HE-Tag: 1642803979-347016 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 Fri, Jan 21, 2022 at 10:59 PM Zi Yan wrote: > > On 21 Jan 2022, at 3:13, Muchun Song wrote: > > > The D-cache maintenance inside move_to_new_page() only consider one page, > > there is still D-cache maintenance issue for tail pages of THP. Fix this > > by using flush_dcache_folio(). > > > > Fixes: 616b8371539a ("mm: thp: enable thp migration in generic path") > > Signed-off-by: Muchun Song > > --- > > mm/migrate.c | 3 +-- > > 1 file changed, 1 insertion(+), 2 deletions(-) > > > > diff --git a/mm/migrate.c b/mm/migrate.c > > index c9296d63878d..daf2b3508670 100644 > > --- a/mm/migrate.c > > +++ b/mm/migrate.c > > @@ -934,8 +934,7 @@ static int move_to_new_page(struct page *newpage, struct page *page, > > page->mapping = NULL; > > > > if (likely(!is_zone_device_page(newpage))) > > - flush_dcache_page(newpage); > > - > > + flush_dcache_folio(page_folio(newpage)); > > } > > out: > > return rc; > > -- > > 2.11.0 > > Yes, the entire THP should be flushed. But it is better > to use a for loop instead of the folio variant, so that the patch > can be ported easily to the stable trees. The for loop can be > converted later when the whole function is converted to use folio. > Agree. Will do. Thanks for your review.