Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
From:   Ankur Arora <ankur.a.arora@oracle.com>
To:     linux-kernel@vger.kernel.org, linux-mm@kvack.org, x86@kernel.org
Cc:     torvalds@linux-foundation.org, akpm@linux-foundation.org,
        luto@kernel.org, bp@alien8.de, dave.hansen@linux.intel.com,
        hpa@zytor.com, mingo@redhat.com, juri.lelli@redhat.com,
        willy@infradead.org, mgorman@suse.de, peterz@infradead.org,
        rostedt@goodmis.org, tglx@linutronix.de,
        vincent.guittot@linaro.org, jon.grimm@amd.com, bharata@amd.com,
        boris.ostrovsky@oracle.com, konrad.wilk@oracle.com,
        ankur.a.arora@oracle.com
Subject: [PATCH 3/9] huge_page: allow arch override for clear/copy_huge_page()
Date:   Sun,  2 Apr 2023 22:22:27 -0700
Message-Id: <20230403052233.1880567-4-ankur.a.arora@oracle.com>
In-Reply-To: <20230403052233.1880567-1-ankur.a.arora@oracle.com>
References: <20230403052233.1880567-1-ankur.a.arora@oracle.com>
Content-Transfer-Encoding: 8bit
Content-Type: text/plain
MIME-Version: 1.0
X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1
X-MS-Exchange-AntiSpam-MessageData-0: =?us-ascii?Q?wlsYQxBY0Nisi8aeBxFdIVyAH4j2k7GBLV9PHGjuPzZYKNSHkfVq6//mQkp9?=
 =?us-ascii?Q?vW5PW+R1Z6w/9s93iHnlLWjJAB3bQRbws17+WSQJND4Gfp3PvWRztXQWPMq8?=
 =?us-ascii?Q?+qUW6tyAcNjZHf1OZnH1Cy3oMSRyLxI4kYk4wfCTroMT8ze/XtV9EWfq/qp/?=
 =?us-ascii?Q?IjqEA/tPRrx+x5Vym+NwWEKG3UIvy5arWju7R8QKENBb2HAVdasmSZjAfAY5?=
 =?us-ascii?Q?vp/E0iBBZb9KoCBuMfz743vKekPiT/mBe1h7zn/nVzXjty0x5wdo+QieQVpP?=
 =?us-ascii?Q?TKFXKf2ha6jcwMMIpBZ5ML8pkoU+L5vXyhRMR4Izw8oNR2hqBNuuIo+4EGal?=
 =?us-ascii?Q?OeK4SvGqIn0xFnmsj5MKXOgJBy9nQd4HR6ZIgKYrYGvsIuE6I/WE4t2ilh3J?=
 =?us-ascii?Q?MBE2L/KoeJJtJ7hHaTIvLP1olsCQR14dSkpo47CoB3PbNyU8oTL0o7h0+gsG?=
 =?us-ascii?Q?e0GageCqBcrxaUpQn867jMFxwdAhoUtXSzX6Tr/i4+SFJ/jvd9ibHI5AT6MK?=
 =?us-ascii?Q?Up9K4q215mC7kKEbjB7M+jWXfQLsRLdcL/WTj037CA3mhYBi1FqRS0+gnEhO?=
 =?us-ascii?Q?la/JL2FtudCOIxfPHEdcZp72HWiweEY3XKlO44LqSmHue/FRTjK7ZRznmCg2?=
 =?us-ascii?Q?fBxFNx5xmALmkQI/wMwO1DCYPP+BGX7BCgMegE/qKeYRPpg/dNEcLJPcfGAo?=
 =?us-ascii?Q?nbamqehrkRW59fqafecZPLGh2F8bFotgqi1Cfp1lgojvzpTkq2XhWl+b3XRo?=
 =?us-ascii?Q?Dr+sfvsmBg4d/CtABr4lweIjsTgchSxPuz0Q6+tFiBuUOSoR5CFpQoLefbmr?=
 =?us-ascii?Q?HvJEL/j2tE5goCBcxzyVl6iChc0+nBn4xW+AQFftwloS6W1RmVuVoXGjjI6C?=
 =?us-ascii?Q?m5FbxWr6l2H+Y/Kn3i6iap6XDVrz7R+eUc+18PpuAY6gFYGLs19L/bSxMxwT?=
 =?us-ascii?Q?RVe+AWAssddLrKBWtsWpnJBawijj+p0+/dS0QIRO+VtqMue2qtYZPJhs5y07?=
 =?us-ascii?Q?xGAOn0fRBvQVOi3kA8aQ5+CHNZCljyl4JZFEIsP3I6UenBNVfBzNmyIJKs7S?=
 =?us-ascii?Q?NRoCYM9ljDzSFr/zV4xAG78VJpdWgoh0uOj+KYEkaEfqMdjpRh5bDBL4Vj0J?=
 =?us-ascii?Q?y/k2K2L/kPVGmJlWfqKR38q28UgPQk2Pp7CZJ81Q4Robaxou0AzCa043/vZl?=
 =?us-ascii?Q?9CduJgc8UzQYr0ZC8wFLxyJjCUoaJVFKo/lqyswWZKCxWHSFTlbyISZD/qkZ?=
 =?us-ascii?Q?NX7v6qwn3yPqRhKSKsG8ul6gfa3YnS3ZRYokuJSmRRE3iPaiuL/W7eIVC8ST?=
 =?us-ascii?Q?W9jiEZf4ZBFBxrEIR+jckelBBTmsGwtBSnjI+feMtbOv0OBUNa4SkCROyMCP?=
 =?us-ascii?Q?+DPg8eoRIm8bIKF/dZZ8HWP4OFVjoP8DSteky1ydF32A9awPOpyzk7VbIU5G?=
 =?us-ascii?Q?RfvESJRXBYVcuy0b46mtXVPDgUJlhnwBuiyOBrYrZdqUiJUUmSHamGjlzUTf?=
 =?us-ascii?Q?VfGMFdKzzkZai6tPg0GTykwCUG+8SiA6m7cNU53mVB/FpyArWZiRNS/Fh4JZ?=
 =?us-ascii?Q?8mZAilp+HIZZwblQlgV/RKPZ6ptPlPjkDZAlB1C3?=
X-MS-Exchange-AntiSpam-ExternalHop-MessageData-ChunkCount: 1
X-MS-Exchange-AntiSpam-ExternalHop-MessageData-0: =?us-ascii?Q?6e0FLCQ+TObGhDfhFPzRPTGMNfJoow+YEhi5Vx+XU3Ub0tJ7l5c6qDftuEAO?=
 =?us-ascii?Q?c3SaPxFK1uzl/sz8J/g5gCAKslwZZWnpTM0IbM3ivxuPrYYrz2dv6CdfVwje?=
 =?us-ascii?Q?/HI9xQayT3Nh65GVA3i/QEO111D36XV0uUAvBK2rontz27fxktQMhHloAoqw?=
 =?us-ascii?Q?4k9on4JYju5AWM/9YzTeg0q3e6FuUgqYsYXoLmKzPZU9DavapHU71P2FczNh?=
 =?us-ascii?Q?LxN9veKWYAPYETmYBvhEn6YzHGnLW/U2OKUYGQaNq7oYzNYCaf42SzCTBTXi?=
 =?us-ascii?Q?tW8eo3suuTdjqtVLHYiRLIM15JOUYQERKF/K/6WLHLCtoWp6dhkpXUlCiRkK?=
 =?us-ascii?Q?igpPdSCt63i9G0BmLBQnjJ6yVXVK6BdUIZPcmg+b38aWQ6xl/u9M8jBil622?=
 =?us-ascii?Q?+w27l9cvmszEB7hye34l0rXilTbe7ke/JvzglVPvTBiyVIna2F7zpmovGS56?=
 =?us-ascii?Q?KCsJwF6ZZvnbh2qc9VnC0YNAWeoEBlz7Md9McaMTZJOHf8V9HFNqmuQfhDai?=
 =?us-ascii?Q?U3xXwEkcymafwQbHx+coINTBWxHUZbgDmzlNsPDVQI+yp7Cg9m2Ua6NRH6Gt?=
 =?us-ascii?Q?Lsorr149K81AakdEKK6c1m2oG774e2Buasg+58kl/6+sYU2MghvWMs2cDVTd?=
 =?us-ascii?Q?6vvT3Vwqvex70e5V9NTF5XiYV7DwmAtF8EF2/3HymWef9Fyqt3BF9gfxxz8O?=
 =?us-ascii?Q?ouZwxx6fvtUdUGR8FWf7nHjZvYmDGSRMe7alpM4448LGcgbL8MVIIy0Mx7P4?=
 =?us-ascii?Q?CQngz8vGWVPYupevmV+4A24uV2xcZLdcKLOF8Fhfhbui/E09JJUZfcVdzVhd?=
 =?us-ascii?Q?tFaaATrL2qwJ/bVqwvbWh21ZvQJKkmmgg9844iwM/gnrM2qYFzIUrZkuRKsW?=
 =?us-ascii?Q?QmfpNVbcD9Vftl2mdoAjvNHJpfo3uPHC/IHtNhPsJP9kRRwiKjbLbm1c9gon?=
 =?us-ascii?Q?pEplWRSwpgx34yf/0kzR9FrfcOsrhYVIvB1AjJTOqu+QOus6gPXqXa27eY/H?=
 =?us-ascii?Q?pu0fdo/fPTtPGGyNPf9yGRW+SZdxB4Rv60p16jWjHr0BJ0L2V3UVNjN2r9Ia?=
 =?us-ascii?Q?0YNO4ynT0L/749d9GhbtxDZ4JrR0ScPUYwPgShHE2rPK3cNLJNYhl5ig4z8g?=
 =?us-ascii?Q?ZUrzvRE08ea8tq3z9csweudX6rPwbaIN7f8Z9n8Ex8mIgccvnOPIG88=3D?=
X-OriginatorOrg: oracle.com
X-MS-Exchange-CrossTenant-Network-Message-Id: 01f37a97-c6f7-4797-e175-08db34036cda
X-MS-Exchange-CrossTenant-AuthSource: CO6PR10MB5409.namprd10.prod.outlook.com
X-MS-Exchange-CrossTenant-AuthAs: Internal
X-MS-Exchange-CrossTenant-OriginalArrivalTime: 03 Apr 2023 05:22:32.1264
 (UTC)
X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted
X-MS-Exchange-CrossTenant-Id: 4e2c6054-71cb-48f1-bd6c-3a9705aca71b
X-MS-Exchange-CrossTenant-MailboxType: HOSTED
X-MS-Exchange-CrossTenant-UserPrincipalName: rNJXMkL48RPF+xFdQXcLCh0so6eMyDa5HL9gezr45m7jf5XtCTvjoS1tnyCjf4dVMTs88RSIBfpiVA+VbXMR13gPNT6KLzT7YbKEoc9Y76Y=
X-MS-Exchange-Transport-CrossTenantHeadersStamped: PH7PR10MB7106
X-Proofpoint-Virus-Version: vendor=baseguard
 engine=ICAP:2.0.254,Aquarius:18.0.942,Hydra:6.0.573,FMLib:17.11.170.22
 definitions=2023-04-03_02,2023-03-31_01,2023-02-09_01
X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 malwarescore=0 adultscore=0
 phishscore=0 bulkscore=0 mlxscore=0 suspectscore=0 spamscore=0
 mlxlogscore=999 classifier=spam adjust=0 reason=mlx scancount=1
 engine=8.12.0-2303200000 definitions=main-2304030039
X-Proofpoint-GUID: ewEv5zCY3Gyz7aBBO5lxVpjQuKxkAKo8
X-Proofpoint-ORIG-GUID: ewEv5zCY3Gyz7aBBO5lxVpjQuKxkAKo8
X-Spam-Status: No, score=-0.9 required=5.0 tests=DKIM_SIGNED,DKIM_VALID,
        DKIM_VALID_AU,DKIM_VALID_EF,RCVD_IN_DNSWL_LOW,RCVD_IN_MSPIKE_H2,
        SPF_HELO_NONE,SPF_NONE autolearn=unavailable autolearn_force=no
        version=3.4.6
X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on
        lindbergh.monkeyblade.net
Precedence: bulk
List-ID: <linux-kernel.vger.kernel.org>
X-Mailing-List: linux-kernel@vger.kernel.org

clear/copy_huge_page() are constrained to operate on a page-at-a-time
because they also handle the CONFIG_HIGHMEM case.

Mark both __weak to allow for arch specific optimizations.

Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Ankur Arora <ankur.a.arora@oracle.com>
---
 mm/memory.c | 18 +++++++++++++-----
 1 file changed, 13 insertions(+), 5 deletions(-)

diff --git a/mm/memory.c b/mm/memory.c
index 6da97e6c7d21..9a6bce384616 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -5645,8 +5645,12 @@ static void clear_gigantic_page(struct page *page,
 	}
 }
 
-void clear_huge_page(struct page *page,
-		     unsigned long addr_hint, unsigned int pages_per_huge_page)
+/*
+ * clear_huge_page(): does page-at-a-time clearing to handle the
+ * CONFIG_HIGHMEM case.
+ */
+__weak void clear_huge_page(struct page *page,
+			    unsigned long addr_hint, unsigned int pages_per_huge_page)
 {
 	unsigned long addr = addr_hint &
 		~(((unsigned long)pages_per_huge_page << PAGE_SHIFT) - 1);
@@ -5712,9 +5716,13 @@ static void copy_user_gigantic_page(struct page *dst, struct page *src,
 	}
 }
 
-void copy_user_huge_page(struct page *dst, struct page *src,
-			 unsigned long addr_hint, struct vm_area_struct *vma,
-			 unsigned int pages_per_huge_page)
+/*
+ * copy_user_huge_page(): does page-at-a-time copying to handle
+ * the CONFIG_HIGHMEM case.
+ */
+__weak void copy_user_huge_page(struct page *dst, struct page *src,
+				unsigned long addr_hint, struct vm_area_struct *vma,
+				unsigned int pages_per_huge_page)
 {
 	unsigned long addr = addr_hint &
 		~(((unsigned long)pages_per_huge_page << PAGE_SHIFT) - 1);
-- 
2.31.1