Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.35 as permitted sender) client-ip=23.128.96.35;
Date:   Thu, 26 Oct 2023 15:12:41 -0400
From:   Gregory Price <gregory.price@memverge.com>
To:     Rik van Riel <riel@surriel.com>
Cc:     Gregory Price <gourry.memverge@gmail.com>, linux-mm@kvack.org,
        akpm@linux-foundation.org, willy@infradead.org, david@redhat.com,
        vbabka@suse.cz, naoya.horiguchi@linux.dev,
        linux-kernel@vger.kernel.org
Subject: Re: [PATCH] kpageflags: respect folio head-page flag placement
Message-ID: <ZTq6KRn9tKp5KOJA@memverge.com>
References: <20231025201237.948993-1-gregory.price@memverge.com>
 <3ac68b3be0f62cfcd930ee84b87fbdc8244fe45e.camel@surriel.com>
Content-Type: text/plain; charset=iso-8859-1
Content-Disposition: inline
Content-Transfer-Encoding: 8bit
In-Reply-To: <3ac68b3be0f62cfcd930ee84b87fbdc8244fe45e.camel@surriel.com>
MIME-Version: 1.0
X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1
X-MS-Exchange-AntiSpam-MessageData-0: =?iso-8859-1?Q?o0UG23SqoPQx1XVJP4FKAWE1KLj0rVB6JG1Tl3ZIZILp7seF1DPILk3Ty9?=
 =?iso-8859-1?Q?CZoKiX9ALDHeovWcBv8kOm0mY6cWjDZVcheunhUeXTRrkypQj8o/EA6crL?=
 =?iso-8859-1?Q?FOA7p/lKx+2gHQb8zRnBHwzE4OofH/ksd0KQzSr/cdzV/63LW51Og72E5A?=
 =?iso-8859-1?Q?4zdgdi9OCPM4nU0RstaTuqMxKoPW+Cy3OmZXx8OZJM1rvYpk13ivy/se0E?=
 =?iso-8859-1?Q?KtF8Yhe8X/ITvdCsS4bKa3R3UKo2FTQgY1jp1CP/UFe3A5nAHaBFwoFqKp?=
 =?iso-8859-1?Q?CiaGlRdpS9ibdKObUq7RBmARJQsGmb9oofdoWkmGXcEqyYOaFy/Lx0pKBK?=
 =?iso-8859-1?Q?lVtpmJkbtHCIlXS0gfo/AURXDu/pD2NDzZ5+0B7FZBUJglZL9jldiCkPAE?=
 =?iso-8859-1?Q?k8fQp46I+kTuHWAK/jTKaDOXomuoRWo/KlVD6M51NKK149FD+uSJOrCwql?=
 =?iso-8859-1?Q?l6keI/0HMouZ1ZVt2uPwnz2ZRdjJL7q7eIp2n9aNlVV008F/X9tVn1CmWR?=
 =?iso-8859-1?Q?pbf6rj8i2poiCRU9ErxwIKtH+UJcI3hJT3Ya/nFpsmT0QH9H0xTVZhM8Ss?=
 =?iso-8859-1?Q?e5ye7eIVHojJGmqFuw+U+hsN3bpw5bfUgMbtKS0fpjr7MW0FvzD7T+imSS?=
 =?iso-8859-1?Q?jtC5QSqr6svr/eyu37opuZQ29YHAxQh0y6bac/ny0sTD/j5XsiN2ENrtAM?=
 =?iso-8859-1?Q?TfIeDCDoOE6AOt5b5CZ1GOOmKwndmGSUlTogFBNh0YWxpDTwsXkXq5l2FE?=
 =?iso-8859-1?Q?3rpieyeP/k4yZsMwlTPujrBPJVYiAURRrYuWIrqcDVCkkbKynOQuG6Cw+z?=
 =?iso-8859-1?Q?Zm+elfAcJukBoESOTjGAFLUdoxk+mUz6uU3cBH7JP2jnI1+yiKdv/2Q/P7?=
 =?iso-8859-1?Q?iAOok4HgQRTzUIlCIM6+B6YxKBNoQ0cbcUfyGkgn0C4n/IZZXakQvBoV4U?=
 =?iso-8859-1?Q?24+aZICKiC8gsC1BgeooIMs6bkX0bpXtMJwZNJ+4SehKiEt2mt0KmJCDJa?=
 =?iso-8859-1?Q?0ADGqC6bfaykjz3V8oOt/k1w2wpV4UQpJD9ZA8vfwHLogUdsVylCaft7KY?=
 =?iso-8859-1?Q?oPIMLUoggtL0J4R3Z/crH9YFTpJKmFEmU5JdhFBFf+E1oF24oRAFa2Pq49?=
 =?iso-8859-1?Q?SpsF120VX1gZZeKuNIhYcHW+igvRhf7v1K33cEQ1uHaNnWBeVyyv0BdqNu?=
 =?iso-8859-1?Q?Ytcv6zHfLTlDGQCYb2O0UvbKo5fCOUhXjoRliPDtoYal8LTkua+EeUC/NF?=
 =?iso-8859-1?Q?a86c++Kh+EGj4sjSjv2TtGdnRvuKovZFgXvQ+PjcucFpAqQcCbfDbMw/Ir?=
 =?iso-8859-1?Q?Wb9ZgfhNJCXRhRxjpBRz83DSnE5JMDFwuYxUhnQnJguZlfVFsThpX+tzUi?=
 =?iso-8859-1?Q?GVMoY1sHnY1/SSpVUhPSctmUUr51w0gMwYKMZAbQJSc/1FxQcFDzToV7dA?=
 =?iso-8859-1?Q?RKPhDlwwG+3WCYyZmiZjLXSjLxIsv8EXlyJralYW73tuSiodQcyeW8ZWx8?=
 =?iso-8859-1?Q?vXQUw2gXiHf5H7VIV4viVjWiBcjyLQxEHNwR0H9s5hhSoqlIjl14SCa1nM?=
 =?iso-8859-1?Q?FFqU9kHnS3E+bGnwsEgd+gijk8XYfgGA93gKinQITixzT9c2BY8fsCHnuK?=
 =?iso-8859-1?Q?jsMMcvVxmpaqHek20LvkJakV1MtyahrF8AsoCgBk2/tiyTIG0UoSt+Ew?=
 =?iso-8859-1?Q?=3D=3D?=
X-OriginatorOrg: memverge.com
X-MS-Exchange-CrossTenant-Network-Message-Id: 72694037-2873-4343-5afc-08dbd657889c
X-MS-Exchange-CrossTenant-AuthSource: SJ0PR17MB5512.namprd17.prod.outlook.com
X-MS-Exchange-CrossTenant-AuthAs: Internal
X-MS-Exchange-CrossTenant-OriginalArrivalTime: 26 Oct 2023 19:12:44.8049
 (UTC)
X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted
X-MS-Exchange-CrossTenant-Id: 5c90cb59-37e7-4c81-9c07-00473d5fb682
X-MS-Exchange-CrossTenant-MailboxType: HOSTED
X-MS-Exchange-CrossTenant-UserPrincipalName: Je808Pjl/Ty7XLRkgClvF+RpbMAGAXzp5ktgNYikvCBiuVB5BJnZiiZfHycPlBZoGTbU1GIMRDQIV2dH5ywRlvN338+CU8WEOpyaSgWmSs8=
X-MS-Exchange-Transport-CrossTenantHeadersStamped: DM4PR17MB5924
X-Spam-Status: No, score=-0.6 required=5.0 tests=DKIM_INVALID,DKIM_SIGNED,
	HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,
	SPF_PASS autolearn=unavailable autolearn_force=no version=3.4.6
X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on groat.vger.email
Precedence: bulk
List-ID: <linux-kernel.vger.kernel.org>
X-Mailing-List: linux-kernel@vger.kernel.org
X-Greylist: Sender passed SPF test, not delayed by milter-greylist-4.6.4 (groat.vger.email [0.0.0.0]); Thu, 26 Oct 2023 12:13:01 -0700 (PDT)

On Wed, Oct 25, 2023 at 09:34:15PM -0400, Rik van Riel wrote:
> On Wed, 2023-10-25 at 16:12 -0400, Gregory Price wrote:
> > ????????u |= kpf_copy_bit(k, KPF_SWAPBACKED,????PG_swapbacked);
> > 
> 
> Aren't PG_locked, PG_reclaim, and PG_swapbacked also maintained only on
> the folio/head?
> 
> Would it make sense to convert those over as well?
> 

I see them registered as PF_NO_TAIL in include/linux/page-flags.h

Certainly i think there are other updates that are likely needed, but
I wasn't quite sure how to handle ONLY_HEAD and NO_TAIL and other
conditionals.  Should the bits always be 0 or should it refer to HEAD?

Just not sure at the moment.

~Gregory