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 A938828CF5F for ; Thu, 9 Jul 2026 13:34:20 +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=1783604063; cv=none; b=rg/+A3KEaTRKJBTtVNRs6PUHcVBXEuaueDWCfXOufM+xPjvpOABrIDqS+lMn2HQ5LkuZIFJr3TJ2fSZSnXvX923QykDECresMeu6o+H98s8K8N+XZ4OXFqZtZQnt2IdWmsuPMAflVXHyrIY157xaRggmJH9/+JzZMSVHCBX5Qkc= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1783604063; c=relaxed/simple; bh=UCBoGFyvDS7VXUCq7xWi4MDCI+kdI7sbuLuwaKPwTdk=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=GcNKOGNvlmEZysYJ553bdBaxkMs/oTqHGUxVPg1RSMA9Os2rITlDF9HosDhcvHLwtUXv9t4Jt5GpK+Xm83AKQij6l9IpuYQ3raKdJRhwumJRgWGqpcbkiQ2C8I8JCHgZmaOt6pMyx1j2oGMPxXpNylahI+Fdf95PcMc22XhV1Oo= 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=TqMFrkLg; 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="TqMFrkLg" 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 2C9D23592; Thu, 9 Jul 2026 06:34:15 -0700 (PDT) Received: from [10.164.148.40] (MacBook-Pro.blr.arm.com [10.164.148.40]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 8B5FE3F85F; Thu, 9 Jul 2026 06:34:15 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=arm.com; s=foss; t=1783604059; bh=UCBoGFyvDS7VXUCq7xWi4MDCI+kdI7sbuLuwaKPwTdk=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=TqMFrkLgbznn2mQhEGHlE2P5owjWK614V8M6f7dmsfN6b/aZqzS3C9G2/3EVQbwL9 5nXcygHeAUw+ndJ4HzjTw6LGTQ2XqyTzpnkiahKBKxHqYeq/DwbtR/gsPmPH5aLGR7 j6gPVUumSswrNs0QlNddls9HTFGWSTxztXsTCnwk= Message-ID: <32c60952-4f80-4cd7-8fe7-003262f09a12@arm.com> Date: Thu, 9 Jul 2026 19:04:06 +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 5/5] mm/rmap: add anon folio unmap dispatcher function To: "David Hildenbrand (Arm)" , akpm@linux-foundation.org, ljs@kernel.org, muchun.song@linux.dev, osalvador@suse.de Cc: riel@surriel.com, liam@infradead.org, vbabka@kernel.org, harry@kernel.org, jannh@google.com, lance.yang@linux.dev, linux-mm@kvack.org, linux-kernel@vger.kernel.org, ryan.roberts@arm.com, anshuman.khandual@arm.com References: <20260707121128.373192-1-dev.jain@arm.com> <20260707121128.373192-6-dev.jain@arm.com> <50b0de85-0bb9-4d09-b32e-31a3a4661379@kernel.org> Content-Language: en-US From: Dev Jain In-Reply-To: <50b0de85-0bb9-4d09-b32e-31a3a4661379@kernel.org> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit On 07/07/26 7:58 pm, David Hildenbrand (Arm) wrote: > On 7/7/26 14:11, Dev Jain wrote: >> Add ttu_anon_folio() as the common entry point for anonymous folio >> unmapping. It dispatches to the lazyfree or swapbacked helper as >> appropriate, and centralizes restoration of cleared PTEs on failure. >> >> No functional change intended. >> >> Signed-off-by: Dev Jain >> --- >> mm/rmap.c | 59 +++++++++++++++++++++++++++++++++---------------------- >> 1 file changed, 36 insertions(+), 23 deletions(-) >> >> diff --git a/mm/rmap.c b/mm/rmap.c >> index ade78df5be2bd..f021ecd51a4a2 100644 >> --- a/mm/rmap.c >> +++ b/mm/rmap.c >> @@ -2171,6 +2171,40 @@ static inline bool ttu_anon_swapbacked_folio(struct vm_area_struct *vma, struct >> return true; >> } >> >> +static inline bool ttu_anon_folio(struct vm_area_struct *vma, struct folio *folio, >> + struct page *subpage, unsigned long address, pte_t *ptep, >> + pte_t pteval, unsigned long nr_pages) >> +{ >> + struct mm_struct *mm = vma->vm_mm; >> + bool ret; >> + >> + /* >> + * Store the swap location in the pte. >> + * See handle_pte_fault() ... >> + */ >> + if (unlikely(folio_test_swapbacked(folio) != >> + folio_test_swapcache(folio))) { >> + WARN_ON_ONCE(1); >> + return false; >> + } >> + >> + /* MADV_FREE page check */ >> + if (!folio_test_swapbacked(folio)) { >> + ret = ttu_anon_lazyfree_folio(vma, folio); >> + if (ret) >> + add_mm_counter(mm, MM_ANONPAGES, -nr_pages); > > Can't the be handled in there as well? Okay. > >> + } else { >> + /* nr_pages > 1 not supported yet */ >> + ret = ttu_anon_swapbacked_folio(vma, folio, subpage, address, >> + ptep, pteval); >> + } >> + >> + if (!ret) >> + set_ptes(mm, address, ptep, pteval, nr_pages); > > It might be cleaner to do that in the caller, where we actually removed the ptes > in the first place? Yes. > >> + >> + return ret; >> +} >> + >> /* >> * @arg: enum ttu_flags will be passed to this argument >> */ >> @@ -2351,31 +2385,10 @@ static bool try_to_unmap_one(struct folio *folio, struct vm_area_struct *vma, >> */ >> dec_mm_counter(mm, mm_counter(folio)); >> } else if (folio_test_anon(folio)) { >> - /* >> - * Store the swap location in the pte. >> - * See handle_pte_fault() ... >> - */ >> - if (unlikely(folio_test_swapbacked(folio) != >> - folio_test_swapcache(folio))) { >> - WARN_ON_ONCE(1); >> + if (!ttu_anon_folio(vma, folio, subpage, address, >> + pvmw.pte, pteval, nr_pages)) >> goto walk_abort; >> - } >> >> - /* MADV_FREE page check */ >> - if (!folio_test_swapbacked(folio)) { >> - if (!ttu_anon_lazyfree_folio(vma, folio)) { >> - set_ptes(mm, address, pvmw.pte, pteval, nr_pages); >> - goto walk_abort; >> - } >> - add_mm_counter(mm, MM_ANONPAGES, -nr_pages); >> - goto finish_unmap; >> - } >> - >> - if (!ttu_anon_swapbacked_folio(vma, folio, subpage, address, >> - pvmw.pte, pteval)) { >> - set_pte_at(mm, address, pvmw.pte, pteval); >> - goto walk_abort; >> - } >> goto finish_unmap; >> } else { >> /* > > Very nice. >