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 3D833C5475B for ; Wed, 6 Mar 2024 13:51:45 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id AF4426B0071; Wed, 6 Mar 2024 08:51:44 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id AA3AE6B0072; Wed, 6 Mar 2024 08:51:44 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 944E56B0075; Wed, 6 Mar 2024 08:51:44 -0500 (EST) 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 821B36B0071 for ; Wed, 6 Mar 2024 08:51:44 -0500 (EST) Received: from smtpin13.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay05.hostedemail.com (Postfix) with ESMTP id 0FA2540FA3 for ; Wed, 6 Mar 2024 13:51:44 +0000 (UTC) X-FDA: 81866752128.13.52E85DE Received: from sin.source.kernel.org (sin.source.kernel.org [145.40.73.55]) by imf14.hostedemail.com (Postfix) with ESMTP id 2413010000B for ; Wed, 6 Mar 2024 13:51:41 +0000 (UTC) Authentication-Results: imf14.hostedemail.com; dkim=pass header.d=linuxfoundation.org header.s=korg header.b=A39kwWOI; dmarc=pass (policy=none) header.from=linuxfoundation.org; spf=pass (imf14.hostedemail.com: domain of gregkh@linuxfoundation.org designates 145.40.73.55 as permitted sender) smtp.mailfrom=gregkh@linuxfoundation.org ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1709733102; 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=nZ8hvWYYjPg/YhdOcV0tEcUMAfjWLA2v6fQiQmz86RU=; b=mnk7/ZrBuLo8+qt9ySBO43OIYMCS34rn/Je5+JhHskg6NEkV9VoRrkm4JDf3TRi0Zyi46I 4lZj2B8sqjzUuR9PL8ADjRmGNAKdh9YUsYBBrk0oBUTtp14no35IwR7ZW2R/OSQsWcaXI9 2ZBPic1/x9p4NdRCljNU2BVvpWFNBHc= ARC-Authentication-Results: i=1; imf14.hostedemail.com; dkim=pass header.d=linuxfoundation.org header.s=korg header.b=A39kwWOI; dmarc=pass (policy=none) header.from=linuxfoundation.org; spf=pass (imf14.hostedemail.com: domain of gregkh@linuxfoundation.org designates 145.40.73.55 as permitted sender) smtp.mailfrom=gregkh@linuxfoundation.org ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1709733102; a=rsa-sha256; cv=none; b=jlJJPI0wRdLk3PIer9NrTcVnqra11RbQ7ZmJQpOicXAxUunH+YSSownpHucKQhaxWMBMx2 WGhkLGfChRW5BS7345XAo7DUK+31Io8Km7dkEdukL6zBoTo8vTl4NhexxEsX8LFc99GL3B 1Yl+MoyrEAyyhBYilUdvc6txwfdDR/Y= Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by sin.source.kernel.org (Postfix) with ESMTP id 0F523CE1D9A; Wed, 6 Mar 2024 13:51:38 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 10904C433F1; Wed, 6 Mar 2024 13:51:36 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1709733097; bh=aiFjeCBLulfJTYlTDxGvoYCYsPSgBsu9exnZA8T53gU=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=A39kwWOIlN1tTvGMCgnNtPrPW9Fv6IcBNiZI2hvUTXJozcUFomlewZYJGyyyLxKnS zJlSqf8PwyNHfST8+bRmJnmXjKVrSqXglYebU+JW24pES/McMZq7mbvRhlaLS0Iixp he8weUxWetwiKKdKoVewjeqPWSSPVwr0QcrwXoiE= Date: Wed, 6 Mar 2024 13:51:34 +0000 From: Greg KH To: Zi Yan Cc: David Hildenbrand , stable@vger.kernel.org, linux-mm@kvack.org, Charan Teja Kalla , "\"Matthew Wilcox (Oracle)\"" , Andrew Morton , Huang Ying , Naoya Horiguchi Subject: Re: [PATCH STABLE v6.1.y] mm/migrate: set swap entry values of THP tail pages properly. Message-ID: <2024030649-utilize-budding-380d@gregkh> References: <20240305161313.90954-1-zi.yan@sent.com> <2024030506-quotable-kerosene-6820@gregkh> <0910e8f0-5490-4d08-ac64-da4077a1e703@redhat.com> <2024030527-footrest-cathedral-5e15@gregkh> <075777FD-8EA9-446F-A52C-96AF43170EA7@nvidia.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <075777FD-8EA9-446F-A52C-96AF43170EA7@nvidia.com> X-Rspam-User: X-Stat-Signature: ixz3gr8uaxyd9dndo3uzitn6bby55gfr X-Rspamd-Server: rspam07 X-Rspamd-Queue-Id: 2413010000B X-HE-Tag: 1709733101-328699 X-HE-Meta: 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 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: List-Subscribe: List-Unsubscribe: On Tue, Mar 05, 2024 at 06:13:39PM -0500, Zi Yan wrote: > On 5 Mar 2024, at 17:32, Greg KH wrote: > > > On Tue, Mar 05, 2024 at 11:09:17PM +0100, David Hildenbrand wrote: > >> On 05.03.24 23:04, Greg KH wrote: > >>> On Tue, Mar 05, 2024 at 11:13:13AM -0500, Zi Yan wrote: > >>>> From: Zi Yan > >>>> > >>>> The tail pages in a THP can have swap entry information stored in their > >>>> private field. When migrating to a new page, all tail pages of the new > >>>> page need to update ->private to avoid future data corruption. > >>>> > >>>> Signed-off-by: Zi Yan > >>>> --- > >>>> mm/migrate.c | 6 +++++- > >>>> 1 file changed, 5 insertions(+), 1 deletion(-) > >>> > >>> What is the git commit id of this change in Linus's tree? > >> > >> Unfortunately, we had to do stable-only versions, because the backport > >> of the "accidental" fix that removes the per-subpage "private" information > >> would be non-trivial, especially for pre-folio-converison times. > >> > >> The accidental fix is > >> > >> 07e09c483cbef2a252f75d95670755a0607288f5 > > > > None of that is obvious at all here, we need loads of documentation in > > the changelog text that says all of that please. > > How about? > > Before 07e09c483cbe ("mm/huge_memory: work on folio->swap instead of > page->private when splitting folio"), when a THP is added into swapcache, > each of its subpages has its own swapcache entry and need ->private pointing > to the right swapcache entry. THP added to swapcache function is added in > 38d8b4e6bdc87 ("mm, THP, swap: delay splitting THP during swap out"). > When THP migration was added in 616b8371539a6 ("mm: thp: enable thp migration in generic path"), it did not take care of swapcached THP's subpages, > neither updated subpage's ->private nor replaced subpage pointer in > the swapcache. Later, e71769ae5260 ("mm: enable thp migration for shmem thp") > fixed swapcache update part. Now this patch fixes the subpage ->private > update part. That's better than what is there now :) So yes, please resend all of these with the new text and then we can queue them up. thanks, greg k-h