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 60A483ED3C8; Wed, 27 May 2026 10:17:06 +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=1779877030; cv=none; b=UNGVJxqOkQsUWakPHGXPnlzc7VT8Nr6NMzfr3ANoTQikteCK0BS2kk4/3i7datjbyHGMyY7EHGFK2JXQQvGpqOv6Ee3mJCiZ2uyR/5XnD+G6R4lA1VowPsD1KK9mHNWp83rpdix4Pg0i+0iCJVVkmUhbVAOn1S6S2IC/LP1Fd9I= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1779877030; c=relaxed/simple; bh=dxunWLVNoBTNDPHHustbHNmVfyF9OQc1rk7qCoIqqx0=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=dzm5Xn4nt4TtmNL5fIMQd4tDXZmBHVQdl/rT2xP2sGwYREPmAw2nH61ac9Xm1Y3c9spYDwUJRzSocavOw2TS4Fc/JFcWtKZmKE/3ngsizxeDgUDgZIqX38amDAYwmkHBsFlSbqM0LcZ5Rk9UM3kc39bNVCbfpdJPbdpLmhALEL4= 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=fmxXQqKU; 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="fmxXQqKU" 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 D05ED169C; Wed, 27 May 2026 03:17:00 -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 C95A03F7D8; Wed, 27 May 2026 03:16:59 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=arm.com; s=foss; t=1779877025; bh=dxunWLVNoBTNDPHHustbHNmVfyF9OQc1rk7qCoIqqx0=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=fmxXQqKUIE7YXewLZD7f6o3CN6kx8C77ayMefofVQvhrdkf1NCB6SbhjaoezhKQGS izyuG3SrVtn/se2hI6rcmbO6WJ/pAuc5SiYa0yYFxfhtGZBEdUOAUsyHtwavejCSt/ gMty1AQ7C57596xePSczg9VbFzWDLqFL1s0GZ8Ek= Message-ID: <48cbab1e-5547-4dd4-8820-6c918b3db537@arm.com> Date: Wed, 27 May 2026 15:46:56 +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 PUD 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 , Dan Williams , Alistair Popple , wangkefeng.wang@huawei.com, chenjun102@huawei.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org, stable@vger.kernel.org References: <20260526101355.1984244-1-yintirui@huawei.com> Content-Language: en-US From: Dev Jain In-Reply-To: <20260526101355.1984244-1-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_pud_locked() updates the file/shmem RSS counter after > dropping the PUD 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: dbe54153296d ("mm/huge_memory: add vmf_insert_folio_pud()") > Cc: > Signed-off-by: Yin Tirui > --- Reviewed-by: Dev Jain > mm/huge_memory.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/mm/huge_memory.c b/mm/huge_memory.c > index a5f4a48b7b77..9832ee910d5e 100644 > --- a/mm/huge_memory.c > +++ b/mm/huge_memory.c > @@ -3027,9 +3027,9 @@ static void __split_huge_pud_locked(struct vm_area_struct *vma, pud_t *pud, > if (!folio_test_referenced(folio) && pud_young(old_pud)) > folio_set_referenced(folio); > folio_remove_rmap_pud(folio, page, vma); > - folio_put(folio); > add_mm_counter(vma->vm_mm, mm_counter_file(folio), > -HPAGE_PUD_NR); > + folio_put(folio); > } > > void __split_huge_pud(struct vm_area_struct *vma, pud_t *pud,