From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 7422941B8E4 for ; Mon, 27 Jul 2026 13:59:11 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1785160754; cv=none; b=fMfWHsR5MYW2/FyNHMoTsxWActtsP2NxfL88b5lS1wHrWE10S1boAEFFoWnSD/h5qMEtT7IJH/4UTMUIWZjyALA0faDJYF1pO7NNEjULQvgqi1TIFlsUnRWLHwpsp6MLBffjHRNDnObo4okGhXVSkJU6wUwwelian2ykENC5rgg= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1785160754; c=relaxed/simple; bh=2QRbg28412wreFAxGBWQ0f3AynsbseyKbrvAhOBu5yw=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=lefLbeeMkECmV0cVJfglOXTMjerZIjCYQSd0PTvb1oeunrX/ZdAincXnf7RNdD42gixxTACC/rTt4w+uY3C682n9u91rP5v89A5pyvLnVHfzSn+JqDhe9hkV+uKzDDvVIG8knwEVC3z2FSP2FsJArQh+XnsDNvrzeA1dsj5NBVo= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=M9XJbpFC; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="M9XJbpFC" Received: by smtp.kernel.org (Postfix) with ESMTPSA id B267B1F000E9; Mon, 27 Jul 2026 13:59:08 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1785160750; bh=JlBgQOsYY3Xxvvlq49+FiktWgQqJ7DTK8k5w3thdHts=; h=Date:From:To:Cc:Subject:References:In-Reply-To; b=M9XJbpFCcrxvKse9y3y2Y1ZZfpoc+CfLvrENY7nJExy3diE04HwsOFe7YjjtERAyM LYWdJRn/NH5sE9nvB1DVLYjJvBAtc+PiZDM0agroCQM5TkSpKlrvmof4LynhSy3xb8 QQKSP2QojAXo0JzkpNcGJUZTQ4KhCeKooQU+fUqRmgwGkoKCEAQmIAsIAnw/7OX++c 3wubRc6iKFxuTuYr/7XjX+hVgyFPpb6wHVWjpyCp0eqdgURgUW1V3Zm1FMAbTA17hv gVt1es+9l6UtxbVFYO/9bifwKsts3nWs2lRoQhA1g4GgNSPRzmUU9ZwJn8Pk1h7CCj Dh4C/lawW9LNQ== Date: Mon, 27 Jul 2026 14:58:54 +0100 From: "Lorenzo Stoakes (ARM)" To: "David Hildenbrand (Arm)" Cc: Hongfu Li , akpm@linux-foundation.org, liam@infradead.org, lihongfu@kylinos.cn, linux-kernel@vger.kernel.org, linux-mm@kvack.org, mhocko@suse.com, rppt@kernel.org, surenb@google.com, vbabka@kernel.org Subject: Re: [PATCH v2 2/2] mm: Extract non-swap page handling to do_non_swap_page() Message-ID: References: <10c60511-c841-4bd8-aa5f-0d826b676533@kernel.org> <20260727121047.4140-1-hongfu.li@linux.dev> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: On Mon, Jul 27, 2026 at 02:16:40PM +0200, David Hildenbrand (Arm) wrote: > On 7/27/26 14:10, Hongfu Li wrote: > >>> mm/memory.c | 120 ++++++++++++++++++++++++++++++---------------------- > >>> 1 file changed, 69 insertions(+), 51 deletions(-) > >>> > >>> diff --git a/mm/memory.c b/mm/memory.c > >>> index ae521baa8c84..50d8e92aef91 100644 > >>> --- a/mm/memory.c > >>> +++ b/mm/memory.c > >>> @@ -4815,6 +4815,74 @@ static void check_swap_exclusive(struct folio *folio, swp_entry_t entry, > >>> } while (--nr_pages); > >>> } > >>> > >>> +static vm_fault_t do_non_swap_page(struct vm_fault *vmf) > >> > >> We're handling softleaf entries that are not swap entries. > >> > >> do_nonswap_softleaf() or sth like that would be better than talking about "page" > >> if there is not even a page. > >> > >> But actually it should be the other way around: > >> > >> do_softleaf_entry() [currently do_swap_page] > >> ... non-swap entries > >> do_swap_entry() > >> > >> Or sth like that. Then, maybe in the future, we can just move do_swap_entry() > >> out of memory.c > >> > >> So we're factoring the wrong thing out in this patch. > > > > Thank you very much for the detailed review, your analysis makes perfect sense to me. > > > > I'm glad to send out v3 shortly for your further review, with > > do_non_swap_page renamed to do_nonswap_softleaf. > > Read again, that's not what I meant. Yeah please do NOT introduce 'nonswap' we already had fun with the nonswap swap entry before :) Quoting David: do_softleaf_entry() [currently do_swap_page] ... non-swap entries do_swap_entry() Also, swap entries _are_ softleaf entries. The whole point of the softleaf change/renaming was to differentiate page table entries that are purely there for mapping stuff from the hardware's point of view (non-present because nothing is mapped there, present if mapping something) vs. something non-present because the entry is software-defined (hence SOFT-leaf). Swap entries are software-defined and thus fall into category. You can see all of the softleaf types trivially in include/linux/leafops.h in enum softleaf_type: enum softleaf_type { /* Fundamental types. */ SOFTLEAF_NONE, SOFTLEAF_SWAP, /* Migration types. */ SOFTLEAF_MIGRATION_READ, SOFTLEAF_MIGRATION_READ_EXCLUSIVE, SOFTLEAF_MIGRATION_WRITE, /* Device types. */ SOFTLEAF_DEVICE_PRIVATE_READ, SOFTLEAF_DEVICE_PRIVATE_WRITE, SOFTLEAF_DEVICE_EXCLUSIVE, /* H/W posion types. */ SOFTLEAF_HWPOISON, /* Marker types. */ SOFTLEAF_MARKER, }; > > -- > Cheers, > > David Cheers, Lorenzo P.S. I do remember suggesting that you _slow down_ :) we are into the quiet period now so let's maybe reduce the pace of series + respins, thanks.