From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by smtp.subspace.kernel.org (Postfix) with ESMTP id D301F3EFFA8; Wed, 27 May 2026 10:15:31 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=217.140.110.172 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1779876936; cv=none; b=cbr75pRzxjrCQl40rZL6HlH700hWBYnDCvfGscBb0RnWT9syDm/s2Q4X6dWOsZTPp2t47xhFV+Z8BPaizONGqEgZHqIpFFjvvcxzf7GuTjsg+XceSbu7rAKKiPGSI/6b0KGML8/O6uXxsmki+wMXyYnogIv2B/D5rF6VA8G3gsM= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1779876936; c=relaxed/simple; bh=11Ch8SRuV30IKc6WYj2PYORtmdlKFlKYIOyzxzCdY/g=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=MQoF4c8Ec0ia3ZYts6kmUNaTsRzTc0AOaFVSaFGObw8MRZYMbY0jhndBGzNkWeZEsoCktsD40Ya65JQTEqTUIzzuCJzPX5RdsO+DKOIO+G+DldfuJH1Tek/gYb3r+BOsoTzTI8AGFcsPNRt2ohV0KL+80bzgiQoWIjBPaH/MoLE= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com; spf=pass smtp.mailfrom=arm.com; dkim=pass (1024-bit key) header.d=arm.com header.i=@arm.com header.b=oSq834UG; arc=none smtp.client-ip=217.140.110.172 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=arm.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=arm.com header.i=@arm.com header.b="oSq834UG" Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id A4003169C; Wed, 27 May 2026 03:15:23 -0700 (PDT) Received: from [10.164.19.7] (unknown [10.164.19.7]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id A9F853F7D8; Wed, 27 May 2026 03:15:22 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=arm.com; s=foss; t=1779876928; bh=11Ch8SRuV30IKc6WYj2PYORtmdlKFlKYIOyzxzCdY/g=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=oSq834UGuKiM2+78TjUMC/7CFpOQSaVkGtkwnwVw6wEh77IDpZniTH2Ll34ktWbVi i10lybDeLgZpwDurSiUporQyyJRmE9NGZNsnDtMONWqT6Jn2VBTCk6pwvwlHwCFci1 PT0wbisNKGnc6MQ25CZJXU4GE2Nuq6evM+eubKdo= Message-ID: <4ac24b2c-7fbe-44bd-9efc-c1add7785453@arm.com> Date: Wed, 27 May 2026 15:45:19 +0530 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH] mm/huge_memory: update file PMD counter before folio_put() To: Yin Tirui , Andrew Morton Cc: David Hildenbrand , Lorenzo Stoakes , Zi Yan , Baolin Wang , "Liam R . Howlett" , Nico Pache , Ryan Roberts , Barry Song , Lance Yang , Vlastimil Babka , Yang Shi , wangkefeng.wang@huawei.com, chenjun102@huawei.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org, stable@vger.kernel.org References: <20260526101337.1984081-1-yintirui@huawei.com> Content-Language: en-US From: Dev Jain In-Reply-To: <20260526101337.1984081-1-yintirui@huawei.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit On 26/05/26 3:43 pm, Yin Tirui wrote: > __split_huge_pmd_locked() updates the file/shmem RSS counter after > dropping the PMD mapping's folio reference. If folio_put() drops the > last reference, mm_counter_file() can later read freed folio state via > folio_test_swapbacked(). > > Move the counter update before folio_put(). > > Fixes: fadae2953072 ("thp: use mm_file_counter to determine update which rss counter") > Cc: > Signed-off-by: Yin Tirui > --- Reviewed-by: Dev Jain > mm/huge_memory.c | 2 ++ > 1 file changed, 2 insertions(+) > > diff --git a/mm/huge_memory.c b/mm/huge_memory.c > index 0135c29a4372..a5f4a48b7b77 100644 > --- a/mm/huge_memory.c > +++ b/mm/huge_memory.c > @@ -3145,7 +3145,9 @@ static void __split_huge_pmd_locked(struct vm_area_struct *vma, pmd_t *pmd, > if (!folio_test_referenced(folio) && pmd_young(old_pmd)) > folio_set_referenced(folio); > folio_remove_rmap_pmd(folio, page, vma); > + add_mm_counter(mm, mm_counter_file(folio), -HPAGE_PMD_NR); > folio_put(folio); > + return; > } > add_mm_counter(mm, mm_counter_file(folio), -HPAGE_PMD_NR); > return;