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 DEA19C00140 for ; Wed, 10 Aug 2022 15:13:46 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 3271C6B0074; Wed, 10 Aug 2022 11:13:46 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 2FCBE6B0075; Wed, 10 Aug 2022 11:13:46 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 14F328E0001; Wed, 10 Aug 2022 11:13:46 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0013.hostedemail.com [216.40.44.13]) by kanga.kvack.org (Postfix) with ESMTP id 047C76B0074 for ; Wed, 10 Aug 2022 11:13:46 -0400 (EDT) Received: from smtpin13.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay02.hostedemail.com (Postfix) with ESMTP id D5009121412 for ; Wed, 10 Aug 2022 15:13:45 +0000 (UTC) X-FDA: 79784027610.13.CF7BEA8 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) by imf23.hostedemail.com (Postfix) with ESMTP id 3D569140055 for ; Wed, 10 Aug 2022 15:13:44 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1660144423; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=VuHszj4L1r9q9EYspHE6rVD8WDtJziprQeMYsIFB++M=; b=MQjSjsZCo7Gw7YGMybHWyziFU07I1uwLYIg7QI3gBHi/4ocBp+D282nAIN6NzBQH++2E15 xt6gjq+7doKdm73Bt/rXR5HoWTCgYYvMDvUZvY3hkih5D7siqSqiUqvPztVu/oArVxxrRX X/R5X+FeiSK8aOMEn8gvxeg0abggOiA= Received: from mail-io1-f71.google.com (mail-io1-f71.google.com [209.85.166.71]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-641-Usc6Zzg_Ot6cqsyjQoCZNw-1; Wed, 10 Aug 2022 11:13:42 -0400 X-MC-Unique: Usc6Zzg_Ot6cqsyjQoCZNw-1 Received: by mail-io1-f71.google.com with SMTP id v20-20020a5ec114000000b00682428f8d31so8136616iol.8 for ; Wed, 10 Aug 2022 08:13:42 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:x-gm-message-state:from:to:cc; bh=VuHszj4L1r9q9EYspHE6rVD8WDtJziprQeMYsIFB++M=; b=2ahvW/ydcRHUbwNZA4WvdoYe3vCDSEKfjiQ6/Gko+SCAvD2MgXl9q/ikFcRK1R6QiT LYgjSm69JZlpodTVonX5FGaIJalBEwkgPcFcErrbzBlYy4ddTcNOdpXaM23+hf9eauxL ce7mOAwKwpreFw//3d+ygNX5clmYXMMk+57pe+ujrNdp4LImZleP8KpZuI++hwvuGeNe FlrYRhnGU2J0ddXFPY1butLgbaQAhLBF90CLqAUyMH+ZnpnISIBjYBw3l1j7VlX4V9ij BM9HogJjoErrlEAhtRW81ldEkUNmeWLfR6iby+wUEuma4LnAnoq7OuqYNYeHALXYy9a0 7S4A== X-Gm-Message-State: ACgBeo0CnupCwy6QOY6H3oP94ShNeED5DiFpbgCgUfJguET9UIuBuyU+ 6o/tdWXwcB09fzhfe2jfYCJHZLlF7vaB/qIo+tttlZIRvV55hiUhrkXgHzhXQME9obzdzaQG1WV 2BQR62nJViVA= X-Received: by 2002:a6b:b548:0:b0:67b:fb71:9b22 with SMTP id e69-20020a6bb548000000b0067bfb719b22mr11630906iof.164.1660144421743; Wed, 10 Aug 2022 08:13:41 -0700 (PDT) X-Google-Smtp-Source: AA6agR58Zmo3JphRCV1dvwo1ydhZTdMnJnzqTvCJD5Jx2PD8aJZzXAXHXuj4C+qYhejwg9wwtr0mow== X-Received: by 2002:a6b:b548:0:b0:67b:fb71:9b22 with SMTP id e69-20020a6bb548000000b0067bfb719b22mr11630892iof.164.1660144421468; Wed, 10 Aug 2022 08:13:41 -0700 (PDT) Received: from xz-m1.local (bras-base-aurron9127w-grc-35-70-27-3-10.dsl.bell.ca. [70.27.3.10]) by smtp.gmail.com with ESMTPSA id o9-20020a056e0214c900b002de990656f5sm2248531ilk.32.2022.08.10.08.13.40 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 10 Aug 2022 08:13:40 -0700 (PDT) Date: Wed, 10 Aug 2022 11:13:39 -0400 From: Peter Xu To: "Huang, Ying" Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, Minchan Kim , David Hildenbrand , Nadav Amit , Andrew Morton , Hugh Dickins , Vlastimil Babka , Andrea Arcangeli , Andi Kleen , "Kirill A . Shutemov" Subject: Re: [PATCH v3 4/7] mm/thp: Carry over dirty bit when thp splits on pmd Message-ID: References: <20220809220100.20033-1-peterx@redhat.com> <20220809220100.20033-5-peterx@redhat.com> <877d3gfwf2.fsf@yhuang6-desk2.ccr.corp.intel.com> MIME-Version: 1.0 In-Reply-To: <877d3gfwf2.fsf@yhuang6-desk2.ccr.corp.intel.com> X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=utf-8 Content-Disposition: inline ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1660144424; a=rsa-sha256; cv=none; b=YZdjuvGmr3Wu1hnXobNESzuhmZG851BMEOGRRaQxVw0oHbrMykZJla+auoYO8TqS/ERff2 +gDYUC8sWKErvPR1GB/O9MjCI92Lsu2IwEobZGqqrf5CpOhkNLwPLaw3hyLUf1fw6v3+4l aNyeOVRqWqCJpomAxsfLJ3eL4RJ4ffg= ARC-Authentication-Results: i=1; imf23.hostedemail.com; dkim=pass header.d=redhat.com header.s=mimecast20190719 header.b=MQjSjsZC; spf=pass (imf23.hostedemail.com: domain of peterx@redhat.com designates 170.10.129.124 as permitted sender) smtp.mailfrom=peterx@redhat.com; dmarc=pass (policy=none) header.from=redhat.com ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1660144424; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=VuHszj4L1r9q9EYspHE6rVD8WDtJziprQeMYsIFB++M=; b=tQc8hoQTWKkxUQLXY7SroX2sIEsjpT5cTr+Dj3vQKUTaJTYnmKQ4+lS8Z62bFMsP9etbRd ymAIpo/hX0TOFP0PmrsMwvXGHhUFjQK7KUEgoBWboCbptSM/yRz61Cm2/RIUKc2kY8J/O6 Qaobi96skWBaOHRVWQumXF2i/pKa+SU= X-Stat-Signature: mu4pnejhb8tfrmkr81r3p8ea4g4d1muf X-Rspamd-Queue-Id: 3D569140055 X-Rspam-User: X-Rspamd-Server: rspam02 Authentication-Results: imf23.hostedemail.com; dkim=pass header.d=redhat.com header.s=mimecast20190719 header.b=MQjSjsZC; spf=pass (imf23.hostedemail.com: domain of peterx@redhat.com designates 170.10.129.124 as permitted sender) smtp.mailfrom=peterx@redhat.com; dmarc=pass (policy=none) header.from=redhat.com X-HE-Tag: 1660144424-173690 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 Wed, Aug 10, 2022 at 02:24:33PM +0800, Huang, Ying wrote: > Peter Xu writes: > > > Carry over the dirty bit from pmd to pte when a huge pmd splits. It > > shouldn't be a correctness issue since when pmd_dirty() we'll have the page > > marked dirty anyway, however having dirty bit carried over helps the next > > initial writes of split ptes on some archs like x86. > > > > Signed-off-by: Peter Xu > > --- > > mm/huge_memory.c | 6 +++++- > > 1 file changed, 5 insertions(+), 1 deletion(-) > > > > diff --git a/mm/huge_memory.c b/mm/huge_memory.c > > index 0611b2fd145a..e8e78d1bac5f 100644 > > --- a/mm/huge_memory.c > > +++ b/mm/huge_memory.c > > @@ -2005,7 +2005,7 @@ static void __split_huge_pmd_locked(struct vm_area_struct *vma, pmd_t *pmd, > > pgtable_t pgtable; > > pmd_t old_pmd, _pmd; > > bool young, write, soft_dirty, pmd_migration = false, uffd_wp = false; > > - bool anon_exclusive = false; > > + bool anon_exclusive = false, dirty = false; > > unsigned long addr; > > int i; > > > > @@ -2098,6 +2098,7 @@ static void __split_huge_pmd_locked(struct vm_area_struct *vma, pmd_t *pmd, > > SetPageDirty(page); > > write = pmd_write(old_pmd); > > young = pmd_young(old_pmd); > > + dirty = pmd_dirty(old_pmd); > > Nitpick: This can be put under > > if (pmd_dirty(old_pmd)) > SetPageDirty(page); > > Not a big deal. > > Reviewed-by: "Huang, Ying" Yeah will do, thanks. -- Peter Xu