From dd19e6d8ffaa1289d75d7833de97faf1b6b2c8e4 Mon Sep 17 00:00:00 2001 From: Alex Sierra Date: Fri, 15 Jul 2022 10:05:12 -0500 Subject: mm: add device coherent vma selection for memory migration This case is used to migrate pages from device memory, back to system memory. Device coherent type memory is cache coherent from device and CPU point of view. Link: https://lkml.kernel.org/r/20220715150521.18165-6-alex.sierra@amd.com Signed-off-by: Alex Sierra Signed-off-by: Christoph Hellwig Acked-by: Felix Kuehling Reviewed-by: Alistair Poppple Reviewed-by: David Hildenbrand Cc: Jason Gunthorpe Cc: Jerome Glisse Cc: Matthew Wilcox Cc: Ralph Campbell Signed-off-by: Andrew Morton --- include/linux/migrate.h | 1 + 1 file changed, 1 insertion(+) (limited to 'include/linux/migrate.h') diff --git a/include/linux/migrate.h b/include/linux/migrate.h index 069a89e847f3..b84908debe5c 100644 --- a/include/linux/migrate.h +++ b/include/linux/migrate.h @@ -148,6 +148,7 @@ static inline unsigned long migrate_pfn(unsigned long pfn) enum migrate_vma_direction { MIGRATE_VMA_SELECT_SYSTEM = 1 << 0, MIGRATE_VMA_SELECT_DEVICE_PRIVATE = 1 << 1, + MIGRATE_VMA_SELECT_DEVICE_COHERENT = 1 << 2, }; struct migrate_vma { -- cgit v1.3-8-gc7d7 From 68f2736a858324c3ec852f6c2cddd9d1c777357d Mon Sep 17 00:00:00 2001 From: "Matthew Wilcox (Oracle)" Date: Tue, 7 Jun 2022 15:38:48 -0400 Subject: mm: Convert all PageMovable users to movable_operations These drivers are rather uncomfortably hammered into the address_space_operations hole. They aren't filesystems and don't behave like filesystems. They just need their own movable_operations structure, which we can point to directly from page->mapping. Signed-off-by: Matthew Wilcox (Oracle) --- Documentation/filesystems/locking.rst | 4 -- Documentation/filesystems/vfs.rst | 12 ---- Documentation/vm/page_migration.rst | 113 +++------------------------------- arch/powerpc/platforms/pseries/cmm.c | 60 +----------------- drivers/misc/vmw_balloon.c | 61 +----------------- drivers/virtio/virtio_balloon.c | 47 +------------- include/linux/balloon_compaction.h | 6 +- include/linux/fs.h | 2 - include/linux/migrate.h | 56 +++++++++++++++-- include/linux/page-flags.h | 2 +- include/uapi/linux/magic.h | 4 -- mm/balloon_compaction.c | 10 ++- mm/compaction.c | 29 ++++----- mm/migrate.c | 24 ++++---- mm/util.c | 4 +- mm/z3fold.c | 84 +++---------------------- mm/zsmalloc.c | 102 +++++++----------------------- 17 files changed, 134 insertions(+), 486 deletions(-) (limited to 'include/linux/migrate.h') diff --git a/Documentation/filesystems/locking.rst b/Documentation/filesystems/locking.rst index c0fe711f14d3..9963d9600b71 100644 --- a/Documentation/filesystems/locking.rst +++ b/Documentation/filesystems/locking.rst @@ -252,9 +252,7 @@ prototypes:: bool (*release_folio)(struct folio *, gfp_t); void (*free_folio)(struct folio *); int (*direct_IO)(struct kiocb *, struct iov_iter *iter); - bool (*isolate_page) (struct page *, isolate_mode_t); int (*migratepage)(struct address_space *, struct page *, struct page *); - void (*putback_page) (struct page *); int (*launder_folio)(struct folio *); bool (*is_partially_uptodate)(struct folio *, size_t from, size_t count); int (*error_remove_page)(struct address_space *, struct page *); @@ -280,9 +278,7 @@ invalidate_folio: yes exclusive release_folio: yes free_folio: yes direct_IO: -isolate_page: yes migratepage: yes (both) -putback_page: yes launder_folio: yes is_partially_uptodate: yes error_remove_page: yes diff --git a/Documentation/filesystems/vfs.rst b/Documentation/filesystems/vfs.rst index a08c652467d7..b51665cdabc4 100644 --- a/Documentation/filesystems/vfs.rst +++ b/Documentation/filesystems/vfs.rst @@ -737,12 +737,8 @@ cache in your filesystem. The following members are defined: bool (*release_folio)(struct folio *, gfp_t); void (*free_folio)(struct folio *); ssize_t (*direct_IO)(struct kiocb *, struct iov_iter *iter); - /* isolate a page for migration */ - bool (*isolate_page) (struct page *, isolate_mode_t); /* migrate the contents of a page to the specified target */ int (*migratepage) (struct page *, struct page *); - /* put migration-failed page back to right list */ - void (*putback_page) (struct page *); int (*launder_folio) (struct folio *); bool (*is_partially_uptodate) (struct folio *, size_t from, @@ -930,11 +926,6 @@ cache in your filesystem. The following members are defined: data directly between the storage and the application's address space. -``isolate_page`` - Called by the VM when isolating a movable non-lru page. If page - is successfully isolated, VM marks the page as PG_isolated via - __SetPageIsolated. - ``migrate_page`` This is used to compact the physical memory usage. If the VM wants to relocate a page (maybe off a memory card that is @@ -942,9 +933,6 @@ cache in your filesystem. The following members are defined: page to this function. migrate_page should transfer any private data across and update any references that it has to the page. -``putback_page`` - Called by the VM when isolated page's migration fails. - ``launder_folio`` Called before freeing a folio - it writes back the dirty folio. To prevent redirtying the folio, it is kept locked during the diff --git a/Documentation/vm/page_migration.rst b/Documentation/vm/page_migration.rst index 8c5cb8147e55..11493bad7112 100644 --- a/Documentation/vm/page_migration.rst +++ b/Documentation/vm/page_migration.rst @@ -152,110 +152,15 @@ Steps: Non-LRU page migration ====================== -Although migration originally aimed for reducing the latency of memory accesses -for NUMA, compaction also uses migration to create high-order pages. +Although migration originally aimed for reducing the latency of memory +accesses for NUMA, compaction also uses migration to create high-order +pages. For compaction purposes, it is also useful to be able to move +non-LRU pages, such as zsmalloc and virtio-balloon pages. -Current problem of the implementation is that it is designed to migrate only -*LRU* pages. However, there are potential non-LRU pages which can be migrated -in drivers, for example, zsmalloc, virtio-balloon pages. - -For virtio-balloon pages, some parts of migration code path have been hooked -up and added virtio-balloon specific functions to intercept migration logics. -It's too specific to a driver so other drivers who want to make their pages -movable would have to add their own specific hooks in the migration path. - -To overcome the problem, VM supports non-LRU page migration which provides -generic functions for non-LRU movable pages without driver specific hooks -in the migration path. - -If a driver wants to make its pages movable, it should define three functions -which are function pointers of struct address_space_operations. - -1. ``bool (*isolate_page) (struct page *page, isolate_mode_t mode);`` - - What VM expects from isolate_page() function of driver is to return *true* - if driver isolates the page successfully. On returning true, VM marks the page - as PG_isolated so concurrent isolation in several CPUs skip the page - for isolation. If a driver cannot isolate the page, it should return *false*. - - Once page is successfully isolated, VM uses page.lru fields so driver - shouldn't expect to preserve values in those fields. - -2. ``int (*migratepage) (struct address_space *mapping,`` -| ``struct page *newpage, struct page *oldpage, enum migrate_mode);`` - - After isolation, VM calls migratepage() of driver with the isolated page. - The function of migratepage() is to move the contents of the old page to the - new page - and set up fields of struct page newpage. Keep in mind that you should - indicate to the VM the oldpage is no longer movable via __ClearPageMovable() - under page_lock if you migrated the oldpage successfully and returned - MIGRATEPAGE_SUCCESS. If driver cannot migrate the page at the moment, driver - can return -EAGAIN. On -EAGAIN, VM will retry page migration in a short time - because VM interprets -EAGAIN as "temporary migration failure". On returning - any error except -EAGAIN, VM will give up the page migration without - retrying. - - Driver shouldn't touch the page.lru field while in the migratepage() function. - -3. ``void (*putback_page)(struct page *);`` - - If migration fails on the isolated page, VM should return the isolated page - to the driver so VM calls the driver's putback_page() with the isolated page. - In this function, the driver should put the isolated page back into its own data - structure. - -Non-LRU movable page flags - - There are two page flags for supporting non-LRU movable page. - - * PG_movable - - Driver should use the function below to make page movable under page_lock:: - - void __SetPageMovable(struct page *page, struct address_space *mapping) - - It needs argument of address_space for registering migration - family functions which will be called by VM. Exactly speaking, - PG_movable is not a real flag of struct page. Rather, VM - reuses the page->mapping's lower bits to represent it:: - - #define PAGE_MAPPING_MOVABLE 0x2 - page->mapping = page->mapping | PAGE_MAPPING_MOVABLE; - - so driver shouldn't access page->mapping directly. Instead, driver should - use page_mapping() which masks off the low two bits of page->mapping under - page lock so it can get the right struct address_space. - - For testing of non-LRU movable pages, VM supports __PageMovable() function. - However, it doesn't guarantee to identify non-LRU movable pages because - the page->mapping field is unified with other variables in struct page. - If the driver releases the page after isolation by VM, page->mapping - doesn't have a stable value although it has PAGE_MAPPING_MOVABLE set - (look at __ClearPageMovable). But __PageMovable() is cheap to call whether - page is LRU or non-LRU movable once the page has been isolated because LRU - pages can never have PAGE_MAPPING_MOVABLE set in page->mapping. It is also - good for just peeking to test non-LRU movable pages before more expensive - checking with lock_page() in pfn scanning to select a victim. - - For guaranteeing non-LRU movable page, VM provides PageMovable() function. - Unlike __PageMovable(), PageMovable() validates page->mapping and - mapping->a_ops->isolate_page under lock_page(). The lock_page() prevents - sudden destroying of page->mapping. - - Drivers using __SetPageMovable() should clear the flag via - __ClearMovablePage() under page_lock() before the releasing the page. - - * PG_isolated - - To prevent concurrent isolation among several CPUs, VM marks isolated page - as PG_isolated under lock_page(). So if a CPU encounters PG_isolated - non-LRU movable page, it can skip it. Driver doesn't need to manipulate the - flag because VM will set/clear it automatically. Keep in mind that if the - driver sees a PG_isolated page, it means the page has been isolated by the - VM so it shouldn't touch the page.lru field. - The PG_isolated flag is aliased with the PG_reclaim flag so drivers - shouldn't use PG_isolated for its own purposes. +If a driver wants to make its pages movable, it should define a struct +movable_operations. It then needs to call __SetPageMovable() on each +page that it may be able to move. This uses the ``page->mapping`` field, +so this field is not available for the driver to use for other purposes. Monitoring Migration ===================== @@ -286,3 +191,5 @@ THP_MIGRATION_FAIL and PGMIGRATE_FAIL to increase. Christoph Lameter, May 8, 2006. Minchan Kim, Mar 28, 2016. + +.. kernel-doc:: include/linux/migrate.h diff --git a/arch/powerpc/platforms/pseries/cmm.c b/arch/powerpc/platforms/pseries/cmm.c index 15ed8206c463..5f4037c1d7fe 100644 --- a/arch/powerpc/platforms/pseries/cmm.c +++ b/arch/powerpc/platforms/pseries/cmm.c @@ -19,9 +19,6 @@ #include #include #include -#include -#include -#include #include #include #include @@ -500,19 +497,6 @@ static struct notifier_block cmm_mem_nb = { }; #ifdef CONFIG_BALLOON_COMPACTION -static struct vfsmount *balloon_mnt; - -static int cmm_init_fs_context(struct fs_context *fc) -{ - return init_pseudo(fc, PPC_CMM_MAGIC) ? 0 : -ENOMEM; -} - -static struct file_system_type balloon_fs = { - .name = "ppc-cmm", - .init_fs_context = cmm_init_fs_context, - .kill_sb = kill_anon_super, -}; - static int cmm_migratepage(struct balloon_dev_info *b_dev_info, struct page *newpage, struct page *page, enum migrate_mode mode) @@ -564,47 +548,13 @@ static int cmm_migratepage(struct balloon_dev_info *b_dev_info, return MIGRATEPAGE_SUCCESS; } -static int cmm_balloon_compaction_init(void) +static void cmm_balloon_compaction_init(void) { - int rc; - balloon_devinfo_init(&b_dev_info); b_dev_info.migratepage = cmm_migratepage; - - balloon_mnt = kern_mount(&balloon_fs); - if (IS_ERR(balloon_mnt)) { - rc = PTR_ERR(balloon_mnt); - balloon_mnt = NULL; - return rc; - } - - b_dev_info.inode = alloc_anon_inode(balloon_mnt->mnt_sb); - if (IS_ERR(b_dev_info.inode)) { - rc = PTR_ERR(b_dev_info.inode); - b_dev_info.inode = NULL; - kern_unmount(balloon_mnt); - balloon_mnt = NULL; - return rc; - } - - b_dev_info.inode->i_mapping->a_ops = &balloon_aops; - return 0; -} -static void cmm_balloon_compaction_deinit(void) -{ - if (b_dev_info.inode) - iput(b_dev_info.inode); - b_dev_info.inode = NULL; - kern_unmount(balloon_mnt); - balloon_mnt = NULL; } #else /* CONFIG_BALLOON_COMPACTION */ -static int cmm_balloon_compaction_init(void) -{ - return 0; -} - -static void cmm_balloon_compaction_deinit(void) +static void cmm_balloon_compaction_init(void) { } #endif /* CONFIG_BALLOON_COMPACTION */ @@ -622,9 +572,7 @@ static int cmm_init(void) if (!firmware_has_feature(FW_FEATURE_CMO) && !simulate) return -EOPNOTSUPP; - rc = cmm_balloon_compaction_init(); - if (rc) - return rc; + cmm_balloon_compaction_init(); rc = register_oom_notifier(&cmm_oom_nb); if (rc < 0) @@ -658,7 +606,6 @@ out_reboot_notifier: out_oom_notifier: unregister_oom_notifier(&cmm_oom_nb); out_balloon_compaction: - cmm_balloon_compaction_deinit(); return rc; } @@ -677,7 +624,6 @@ static void cmm_exit(void) unregister_memory_notifier(&cmm_mem_nb); cmm_free_pages(atomic_long_read(&loaned_pages)); cmm_unregister_sysfs(&cmm_dev); - cmm_balloon_compaction_deinit(); } /** diff --git a/drivers/misc/vmw_balloon.c b/drivers/misc/vmw_balloon.c index 086ce77d9074..85dd6aa33df6 100644 --- a/drivers/misc/vmw_balloon.c +++ b/drivers/misc/vmw_balloon.c @@ -29,8 +29,6 @@ #include #include #include -#include -#include #include #include #include @@ -1730,20 +1728,6 @@ static inline void vmballoon_debugfs_exit(struct vmballoon *b) #ifdef CONFIG_BALLOON_COMPACTION - -static int vmballoon_init_fs_context(struct fs_context *fc) -{ - return init_pseudo(fc, BALLOON_VMW_MAGIC) ? 0 : -ENOMEM; -} - -static struct file_system_type vmballoon_fs = { - .name = "balloon-vmware", - .init_fs_context = vmballoon_init_fs_context, - .kill_sb = kill_anon_super, -}; - -static struct vfsmount *vmballoon_mnt; - /** * vmballoon_migratepage() - migrates a balloon page. * @b_dev_info: balloon device information descriptor. @@ -1862,21 +1846,6 @@ out_unlock: return ret; } -/** - * vmballoon_compaction_deinit() - removes compaction related data. - * - * @b: pointer to the balloon. - */ -static void vmballoon_compaction_deinit(struct vmballoon *b) -{ - if (!IS_ERR(b->b_dev_info.inode)) - iput(b->b_dev_info.inode); - - b->b_dev_info.inode = NULL; - kern_unmount(vmballoon_mnt); - vmballoon_mnt = NULL; -} - /** * vmballoon_compaction_init() - initialized compaction for the balloon. * @@ -1888,33 +1857,15 @@ static void vmballoon_compaction_deinit(struct vmballoon *b) * * Return: zero on success or error code on failure. */ -static __init int vmballoon_compaction_init(struct vmballoon *b) +static __init void vmballoon_compaction_init(struct vmballoon *b) { - vmballoon_mnt = kern_mount(&vmballoon_fs); - if (IS_ERR(vmballoon_mnt)) - return PTR_ERR(vmballoon_mnt); - b->b_dev_info.migratepage = vmballoon_migratepage; - b->b_dev_info.inode = alloc_anon_inode(vmballoon_mnt->mnt_sb); - - if (IS_ERR(b->b_dev_info.inode)) - return PTR_ERR(b->b_dev_info.inode); - - b->b_dev_info.inode->i_mapping->a_ops = &balloon_aops; - return 0; } #else /* CONFIG_BALLOON_COMPACTION */ - -static void vmballoon_compaction_deinit(struct vmballoon *b) -{ -} - -static int vmballoon_compaction_init(struct vmballoon *b) +static inline void vmballoon_compaction_init(struct vmballoon *b) { - return 0; } - #endif /* CONFIG_BALLOON_COMPACTION */ static int __init vmballoon_init(void) @@ -1939,9 +1890,7 @@ static int __init vmballoon_init(void) * balloon_devinfo_init() . */ balloon_devinfo_init(&balloon.b_dev_info); - error = vmballoon_compaction_init(&balloon); - if (error) - goto fail; + vmballoon_compaction_init(&balloon); INIT_LIST_HEAD(&balloon.huge_pages); spin_lock_init(&balloon.comm_lock); @@ -1958,7 +1907,6 @@ static int __init vmballoon_init(void) return 0; fail: vmballoon_unregister_shrinker(&balloon); - vmballoon_compaction_deinit(&balloon); return error; } @@ -1985,8 +1933,5 @@ static void __exit vmballoon_exit(void) */ vmballoon_send_start(&balloon, 0); vmballoon_pop(&balloon); - - /* Only once we popped the balloon, compaction can be deinit */ - vmballoon_compaction_deinit(&balloon); } module_exit(vmballoon_exit); diff --git a/drivers/virtio/virtio_balloon.c b/drivers/virtio/virtio_balloon.c index b9737da6c4dd..bd360b91e9d3 100644 --- a/drivers/virtio/virtio_balloon.c +++ b/drivers/virtio/virtio_balloon.c @@ -17,9 +17,6 @@ #include #include #include -#include -#include -#include #include /* @@ -42,10 +39,6 @@ (1 << (VIRTIO_BALLOON_HINT_BLOCK_ORDER + PAGE_SHIFT)) #define VIRTIO_BALLOON_HINT_BLOCK_PAGES (1 << VIRTIO_BALLOON_HINT_BLOCK_ORDER) -#ifdef CONFIG_BALLOON_COMPACTION -static struct vfsmount *balloon_mnt; -#endif - enum virtio_balloon_vq { VIRTIO_BALLOON_VQ_INFLATE, VIRTIO_BALLOON_VQ_DEFLATE, @@ -805,18 +798,6 @@ static int virtballoon_migratepage(struct balloon_dev_info *vb_dev_info, return MIGRATEPAGE_SUCCESS; } - -static int balloon_init_fs_context(struct fs_context *fc) -{ - return init_pseudo(fc, BALLOON_KVM_MAGIC) ? 0 : -ENOMEM; -} - -static struct file_system_type balloon_fs = { - .name = "balloon-kvm", - .init_fs_context = balloon_init_fs_context, - .kill_sb = kill_anon_super, -}; - #endif /* CONFIG_BALLOON_COMPACTION */ static unsigned long shrink_free_pages(struct virtio_balloon *vb, @@ -909,19 +890,7 @@ static int virtballoon_probe(struct virtio_device *vdev) goto out_free_vb; #ifdef CONFIG_BALLOON_COMPACTION - balloon_mnt = kern_mount(&balloon_fs); - if (IS_ERR(balloon_mnt)) { - err = PTR_ERR(balloon_mnt); - goto out_del_vqs; - } - vb->vb_dev_info.migratepage = virtballoon_migratepage; - vb->vb_dev_info.inode = alloc_anon_inode(balloon_mnt->mnt_sb); - if (IS_ERR(vb->vb_dev_info.inode)) { - err = PTR_ERR(vb->vb_dev_info.inode); - goto out_kern_unmount; - } - vb->vb_dev_info.inode->i_mapping->a_ops = &balloon_aops; #endif if (virtio_has_feature(vdev, VIRTIO_BALLOON_F_FREE_PAGE_HINT)) { /* @@ -930,13 +899,13 @@ static int virtballoon_probe(struct virtio_device *vdev) */ if (virtqueue_get_vring_size(vb->free_page_vq) < 2) { err = -ENOSPC; - goto out_iput; + goto out_del_vqs; } vb->balloon_wq = alloc_workqueue("balloon-wq", WQ_FREEZABLE | WQ_CPU_INTENSIVE, 0); if (!vb->balloon_wq) { err = -ENOMEM; - goto out_iput; + goto out_del_vqs; } INIT_WORK(&vb->report_free_page_work, report_free_page_func); vb->cmd_id_received_cache = VIRTIO_BALLOON_CMD_ID_STOP; @@ -1030,13 +999,7 @@ out_unregister_shrinker: out_del_balloon_wq: if (virtio_has_feature(vdev, VIRTIO_BALLOON_F_FREE_PAGE_HINT)) destroy_workqueue(vb->balloon_wq); -out_iput: -#ifdef CONFIG_BALLOON_COMPACTION - iput(vb->vb_dev_info.inode); -out_kern_unmount: - kern_unmount(balloon_mnt); out_del_vqs: -#endif vdev->config->del_vqs(vdev); out_free_vb: kfree(vb); @@ -1083,12 +1046,6 @@ static void virtballoon_remove(struct virtio_device *vdev) } remove_common(vb); -#ifdef CONFIG_BALLOON_COMPACTION - if (vb->vb_dev_info.inode) - iput(vb->vb_dev_info.inode); - - kern_unmount(balloon_mnt); -#endif kfree(vb); } diff --git a/include/linux/balloon_compaction.h b/include/linux/balloon_compaction.h index edb7f6d41faa..5ca2d5699620 100644 --- a/include/linux/balloon_compaction.h +++ b/include/linux/balloon_compaction.h @@ -57,7 +57,6 @@ struct balloon_dev_info { struct list_head pages; /* Pages enqueued & handled to Host */ int (*migratepage)(struct balloon_dev_info *, struct page *newpage, struct page *page, enum migrate_mode mode); - struct inode *inode; }; extern struct page *balloon_page_alloc(void); @@ -75,11 +74,10 @@ static inline void balloon_devinfo_init(struct balloon_dev_info *balloon) spin_lock_init(&balloon->pages_lock); INIT_LIST_HEAD(&balloon->pages); balloon->migratepage = NULL; - balloon->inode = NULL; } #ifdef CONFIG_BALLOON_COMPACTION -extern const struct address_space_operations balloon_aops; +extern const struct movable_operations balloon_mops; /* * balloon_page_insert - insert a page into the balloon's page list and make @@ -94,7 +92,7 @@ static inline void balloon_page_insert(struct balloon_dev_info *balloon, struct page *page) { __SetPageOffline(page); - __SetPageMovable(page, balloon->inode->i_mapping); + __SetPageMovable(page, &balloon_mops); set_page_private(page, (unsigned long)balloon); list_add(&page->lru, &balloon->pages); } diff --git a/include/linux/fs.h b/include/linux/fs.h index 9ad5e3520fae..5d8ee3155ca2 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -367,8 +367,6 @@ struct address_space_operations { */ int (*migratepage) (struct address_space *, struct page *, struct page *, enum migrate_mode); - bool (*isolate_page)(struct page *, isolate_mode_t); - void (*putback_page)(struct page *); int (*launder_folio)(struct folio *); bool (*is_partially_uptodate) (struct folio *, size_t from, size_t count); diff --git a/include/linux/migrate.h b/include/linux/migrate.h index 069a89e847f3..82c735ba6109 100644 --- a/include/linux/migrate.h +++ b/include/linux/migrate.h @@ -19,6 +19,43 @@ struct migration_target_control; */ #define MIGRATEPAGE_SUCCESS 0 +/** + * struct movable_operations - Driver page migration + * @isolate_page: + * The VM calls this function to prepare the page to be moved. The page + * is locked and the driver should not unlock it. The driver should + * return ``true`` if the page is movable and ``false`` if it is not + * currently movable. After this function returns, the VM uses the + * page->lru field, so the driver must preserve any information which + * is usually stored here. + * + * @migrate_page: + * After isolation, the VM calls this function with the isolated + * @src page. The driver should copy the contents of the + * @src page to the @dst page and set up the fields of @dst page. + * Both pages are locked. + * If page migration is successful, the driver should call + * __ClearPageMovable(@src) and return MIGRATEPAGE_SUCCESS. + * If the driver cannot migrate the page at the moment, it can return + * -EAGAIN. The VM interprets this as a temporary migration failure and + * will retry it later. Any other error value is a permanent migration + * failure and migration will not be retried. + * The driver shouldn't touch the @src->lru field while in the + * migrate_page() function. It may write to @dst->lru. + * + * @putback_page: + * If migration fails on the isolated page, the VM informs the driver + * that the page is no longer a candidate for migration by calling + * this function. The driver should put the isolated page back into + * its own data structure. + */ +struct movable_operations { + bool (*isolate_page)(struct page *, isolate_mode_t); + int (*migrate_page)(struct page *dst, struct page *src, + enum migrate_mode); + void (*putback_page)(struct page *); +}; + /* Defined in mm/debug.c: */ extern const char *migrate_reason_names[MR_TYPES]; @@ -91,13 +128,13 @@ static inline int next_demotion_node(int node) #endif #ifdef CONFIG_COMPACTION -extern int PageMovable(struct page *page); -extern void __SetPageMovable(struct page *page, struct address_space *mapping); -extern void __ClearPageMovable(struct page *page); +bool PageMovable(struct page *page); +void __SetPageMovable(struct page *page, const struct movable_operations *ops); +void __ClearPageMovable(struct page *page); #else -static inline int PageMovable(struct page *page) { return 0; } +static inline bool PageMovable(struct page *page) { return false; } static inline void __SetPageMovable(struct page *page, - struct address_space *mapping) + const struct movable_operations *ops) { } static inline void __ClearPageMovable(struct page *page) @@ -110,6 +147,15 @@ static inline bool folio_test_movable(struct folio *folio) return PageMovable(&folio->page); } +static inline +const struct movable_operations *page_movable_ops(struct page *page) +{ + VM_BUG_ON(!__PageMovable(page)); + + return (const struct movable_operations *) + ((unsigned long)page->mapping - PAGE_MAPPING_MOVABLE); +} + #ifdef CONFIG_NUMA_BALANCING extern int migrate_misplaced_page(struct page *page, struct vm_area_struct *vma, int node); diff --git a/include/linux/page-flags.h b/include/linux/page-flags.h index e66f7aa3191d..3f5490f6f038 100644 --- a/include/linux/page-flags.h +++ b/include/linux/page-flags.h @@ -639,7 +639,7 @@ __PAGEFLAG(Reported, reported, PF_NO_COMPOUND) * structure which KSM associates with that merged page. See ksm.h. * * PAGE_MAPPING_KSM without PAGE_MAPPING_ANON is used for non-lru movable - * page and then page->mapping points a struct address_space. + * page and then page->mapping points to a struct movable_operations. * * Please note that, confusingly, "page_mapping" refers to the inode * address_space which maps the page from disk; whereas "page_mapped" diff --git a/include/uapi/linux/magic.h b/include/uapi/linux/magic.h index f724129c0425..6325d1d0e90f 100644 --- a/include/uapi/linux/magic.h +++ b/include/uapi/linux/magic.h @@ -98,12 +98,8 @@ /* Since UDF 2.01 is ISO 13346 based... */ #define UDF_SUPER_MAGIC 0x15013346 -#define BALLOON_KVM_MAGIC 0x13661366 -#define ZSMALLOC_MAGIC 0x58295829 #define DMA_BUF_MAGIC 0x444d4142 /* "DMAB" */ #define DEVMEM_MAGIC 0x454d444d /* "DMEM" */ -#define Z3FOLD_MAGIC 0x33 -#define PPC_CMM_MAGIC 0xc7571590 #define SECRETMEM_MAGIC 0x5345434d /* "SECM" */ #endif /* __LINUX_MAGIC_H__ */ diff --git a/mm/balloon_compaction.c b/mm/balloon_compaction.c index 4b8eab4b3f45..22c96fed70b5 100644 --- a/mm/balloon_compaction.c +++ b/mm/balloon_compaction.c @@ -228,10 +228,8 @@ static void balloon_page_putback(struct page *page) spin_unlock_irqrestore(&b_dev_info->pages_lock, flags); } - /* move_to_new_page() counterpart for a ballooned page */ -static int balloon_page_migrate(struct address_space *mapping, - struct page *newpage, struct page *page, +static int balloon_page_migrate(struct page *newpage, struct page *page, enum migrate_mode mode) { struct balloon_dev_info *balloon = balloon_page_device(page); @@ -250,11 +248,11 @@ static int balloon_page_migrate(struct address_space *mapping, return balloon->migratepage(balloon, newpage, page, mode); } -const struct address_space_operations balloon_aops = { - .migratepage = balloon_page_migrate, +const struct movable_operations balloon_mops = { + .migrate_page = balloon_page_migrate, .isolate_page = balloon_page_isolate, .putback_page = balloon_page_putback, }; -EXPORT_SYMBOL_GPL(balloon_aops); +EXPORT_SYMBOL_GPL(balloon_mops); #endif /* CONFIG_BALLOON_COMPACTION */ diff --git a/mm/compaction.c b/mm/compaction.c index 1f89b969c12b..f23efba1d118 100644 --- a/mm/compaction.c +++ b/mm/compaction.c @@ -110,28 +110,27 @@ static void split_map_pages(struct list_head *list) } #ifdef CONFIG_COMPACTION - -int PageMovable(struct page *page) +bool PageMovable(struct page *page) { - struct address_space *mapping; + const struct movable_operations *mops; VM_BUG_ON_PAGE(!PageLocked(page), page); if (!__PageMovable(page)) - return 0; + return false; - mapping = page_mapping(page); - if (mapping && mapping->a_ops && mapping->a_ops->isolate_page) - return 1; + mops = page_movable_ops(page); + if (mops) + return true; - return 0; + return false; } EXPORT_SYMBOL(PageMovable); -void __SetPageMovable(struct page *page, struct address_space *mapping) +void __SetPageMovable(struct page *page, const struct movable_operations *mops) { VM_BUG_ON_PAGE(!PageLocked(page), page); - VM_BUG_ON_PAGE((unsigned long)mapping & PAGE_MAPPING_MOVABLE, page); - page->mapping = (void *)((unsigned long)mapping | PAGE_MAPPING_MOVABLE); + VM_BUG_ON_PAGE((unsigned long)mops & PAGE_MAPPING_MOVABLE, page); + page->mapping = (void *)((unsigned long)mops | PAGE_MAPPING_MOVABLE); } EXPORT_SYMBOL(__SetPageMovable); @@ -139,12 +138,10 @@ void __ClearPageMovable(struct page *page) { VM_BUG_ON_PAGE(!PageMovable(page), page); /* - * Clear registered address_space val with keeping PAGE_MAPPING_MOVABLE - * flag so that VM can catch up released page by driver after isolation. - * With it, VM migration doesn't try to put it back. + * This page still has the type of a movable page, but it's + * actually not movable any more. */ - page->mapping = (void *)((unsigned long)page->mapping & - PAGE_MAPPING_MOVABLE); + page->mapping = (void *)PAGE_MAPPING_MOVABLE; } EXPORT_SYMBOL(__ClearPageMovable); diff --git a/mm/migrate.c b/mm/migrate.c index 6c1ea61f39d8..491f03747832 100644 --- a/mm/migrate.c +++ b/mm/migrate.c @@ -59,7 +59,7 @@ int isolate_movable_page(struct page *page, isolate_mode_t mode) { - struct address_space *mapping; + const struct movable_operations *mops; /* * Avoid burning cycles with pages that are yet under __free_pages(), @@ -97,10 +97,10 @@ int isolate_movable_page(struct page *page, isolate_mode_t mode) if (!PageMovable(page) || PageIsolated(page)) goto out_no_isolated; - mapping = page_mapping(page); - VM_BUG_ON_PAGE(!mapping, page); + mops = page_movable_ops(page); + VM_BUG_ON_PAGE(!mops, page); - if (!mapping->a_ops->isolate_page(page, mode)) + if (!mops->isolate_page(page, mode)) goto out_no_isolated; /* Driver shouldn't use PG_isolated bit of page->flags */ @@ -120,10 +120,9 @@ out: static void putback_movable_page(struct page *page) { - struct address_space *mapping; + const struct movable_operations *mops = page_movable_ops(page); - mapping = page_mapping(page); - mapping->a_ops->putback_page(page); + mops->putback_page(page); ClearPageIsolated(page); } @@ -846,16 +845,15 @@ static int fallback_migrate_page(struct address_space *mapping, static int move_to_new_folio(struct folio *dst, struct folio *src, enum migrate_mode mode) { - struct address_space *mapping; int rc = -EAGAIN; bool is_lru = !__PageMovable(&src->page); VM_BUG_ON_FOLIO(!folio_test_locked(src), src); VM_BUG_ON_FOLIO(!folio_test_locked(dst), dst); - mapping = folio_mapping(src); - if (likely(is_lru)) { + struct address_space *mapping = folio_mapping(src); + if (!mapping) rc = migrate_page(mapping, &dst->page, &src->page, mode); else if (mapping->a_ops->migratepage) @@ -872,6 +870,8 @@ static int move_to_new_folio(struct folio *dst, struct folio *src, rc = fallback_migrate_page(mapping, &dst->page, &src->page, mode); } else { + const struct movable_operations *mops; + /* * In case of non-lru page, it could be released after * isolation step. In that case, we shouldn't try migration. @@ -883,8 +883,8 @@ static int move_to_new_folio(struct folio *dst, struct folio *src, goto out; } - rc = mapping->a_ops->migratepage(mapping, &dst->page, - &src->page, mode); + mops = page_movable_ops(&src->page); + rc = mops->migrate_page(&dst->page, &src->page, mode); WARN_ON_ONCE(rc == MIGRATEPAGE_SUCCESS && !folio_test_isolated(src)); } diff --git a/mm/util.c b/mm/util.c index 0837570c9225..53af0e79d3e4 100644 --- a/mm/util.c +++ b/mm/util.c @@ -804,10 +804,10 @@ struct address_space *folio_mapping(struct folio *folio) return swap_address_space(folio_swap_entry(folio)); mapping = folio->mapping; - if ((unsigned long)mapping & PAGE_MAPPING_ANON) + if ((unsigned long)mapping & PAGE_MAPPING_FLAGS) return NULL; - return (void *)((unsigned long)mapping & ~PAGE_MAPPING_FLAGS); + return mapping; } EXPORT_SYMBOL(folio_mapping); diff --git a/mm/z3fold.c b/mm/z3fold.c index f41f8b0d9e9a..cf71da10d04e 100644 --- a/mm/z3fold.c +++ b/mm/z3fold.c @@ -34,15 +34,11 @@ #include #include #include -#include -#include -#include #include #include #include #include #include -#include #include /* @@ -149,7 +145,6 @@ struct z3fold_header { * @compact_wq: workqueue for page layout background optimization * @release_wq: workqueue for safe page release * @work: work_struct for safe page release - * @inode: inode for z3fold pseudo filesystem * * This structure is allocated at pool creation time and maintains metadata * pertaining to a particular z3fold pool. @@ -169,7 +164,6 @@ struct z3fold_pool { struct workqueue_struct *compact_wq; struct workqueue_struct *release_wq; struct work_struct work; - struct inode *inode; }; /* @@ -334,54 +328,6 @@ static inline void free_handle(unsigned long handle, struct z3fold_header *zhdr) } } -static int z3fold_init_fs_context(struct fs_context *fc) -{ - return init_pseudo(fc, Z3FOLD_MAGIC) ? 0 : -ENOMEM; -} - -static struct file_system_type z3fold_fs = { - .name = "z3fold", - .init_fs_context = z3fold_init_fs_context, - .kill_sb = kill_anon_super, -}; - -static struct vfsmount *z3fold_mnt; -static int __init z3fold_mount(void) -{ - int ret = 0; - - z3fold_mnt = kern_mount(&z3fold_fs); - if (IS_ERR(z3fold_mnt)) - ret = PTR_ERR(z3fold_mnt); - - return ret; -} - -static void z3fold_unmount(void) -{ - kern_unmount(z3fold_mnt); -} - -static const struct address_space_operations z3fold_aops; -static int z3fold_register_migration(struct z3fold_pool *pool) -{ - pool->inode = alloc_anon_inode(z3fold_mnt->mnt_sb); - if (IS_ERR(pool->inode)) { - pool->inode = NULL; - return 1; - } - - pool->inode->i_mapping->private_data = pool; - pool->inode->i_mapping->a_ops = &z3fold_aops; - return 0; -} - -static void z3fold_unregister_migration(struct z3fold_pool *pool) -{ - if (pool->inode) - iput(pool->inode); -} - /* Initializes the z3fold header of a newly allocated z3fold page */ static struct z3fold_header *init_z3fold_page(struct page *page, bool headless, struct z3fold_pool *pool, gfp_t gfp) @@ -1002,14 +948,10 @@ static struct z3fold_pool *z3fold_create_pool(const char *name, gfp_t gfp, pool->release_wq = create_singlethread_workqueue(pool->name); if (!pool->release_wq) goto out_wq; - if (z3fold_register_migration(pool)) - goto out_rwq; INIT_WORK(&pool->work, free_pages_work); pool->ops = ops; return pool; -out_rwq: - destroy_workqueue(pool->release_wq); out_wq: destroy_workqueue(pool->compact_wq); out_unbuddied: @@ -1043,11 +985,12 @@ static void z3fold_destroy_pool(struct z3fold_pool *pool) destroy_workqueue(pool->compact_wq); destroy_workqueue(pool->release_wq); - z3fold_unregister_migration(pool); free_percpu(pool->unbuddied); kfree(pool); } +static const struct movable_operations z3fold_mops; + /** * z3fold_alloc() - allocates a region of a given size * @pool: z3fold pool from which to allocate @@ -1117,11 +1060,11 @@ retry: } if (can_sleep) { lock_page(page); - __SetPageMovable(page, pool->inode->i_mapping); + __SetPageMovable(page, &z3fold_mops); unlock_page(page); } else { WARN_ON(!trylock_page(page)); - __SetPageMovable(page, pool->inode->i_mapping); + __SetPageMovable(page, &z3fold_mops); unlock_page(page); } z3fold_page_lock(zhdr); @@ -1554,12 +1497,11 @@ out: return false; } -static int z3fold_page_migrate(struct address_space *mapping, struct page *newpage, - struct page *page, enum migrate_mode mode) +static int z3fold_page_migrate(struct page *newpage, struct page *page, + enum migrate_mode mode) { struct z3fold_header *zhdr, *new_zhdr; struct z3fold_pool *pool; - struct address_space *new_mapping; VM_BUG_ON_PAGE(!PageMovable(page), page); VM_BUG_ON_PAGE(!PageIsolated(page), page); @@ -1592,7 +1534,6 @@ static int z3fold_page_migrate(struct address_space *mapping, struct page *newpa * so we only have to reinitialize it. */ INIT_LIST_HEAD(&new_zhdr->buddy); - new_mapping = page_mapping(page); __ClearPageMovable(page); get_page(newpage); @@ -1608,7 +1549,7 @@ static int z3fold_page_migrate(struct address_space *mapping, struct page *newpa spin_lock(&pool->lock); list_add(&newpage->lru, &pool->lru); spin_unlock(&pool->lock); - __SetPageMovable(newpage, new_mapping); + __SetPageMovable(newpage, &z3fold_mops); z3fold_page_unlock(new_zhdr); queue_work_on(new_zhdr->cpu, pool->compact_wq, &new_zhdr->work); @@ -1642,9 +1583,9 @@ static void z3fold_page_putback(struct page *page) z3fold_page_unlock(zhdr); } -static const struct address_space_operations z3fold_aops = { +static const struct movable_operations z3fold_mops = { .isolate_page = z3fold_page_isolate, - .migratepage = z3fold_page_migrate, + .migrate_page = z3fold_page_migrate, .putback_page = z3fold_page_putback, }; @@ -1746,17 +1687,11 @@ MODULE_ALIAS("zpool-z3fold"); static int __init init_z3fold(void) { - int ret; - /* * Make sure the z3fold header is not larger than the page size and * there has remaining spaces for its buddy. */ BUILD_BUG_ON(ZHDR_SIZE_ALIGNED > PAGE_SIZE - CHUNK_SIZE); - ret = z3fold_mount(); - if (ret) - return ret; - zpool_register_driver(&z3fold_zpool_driver); return 0; @@ -1764,7 +1699,6 @@ static int __init init_z3fold(void) static void __exit exit_z3fold(void) { - z3fold_unmount(); zpool_unregister_driver(&z3fold_zpool_driver); } diff --git a/mm/zsmalloc.c b/mm/zsmalloc.c index 5d5fc04385b8..71d6edcbea48 100644 --- a/mm/zsmalloc.c +++ b/mm/zsmalloc.c @@ -41,7 +41,6 @@ #include #include #include -#include #include #include #include @@ -59,8 +58,6 @@ #include #include #include -#include -#include #include #include #include @@ -177,10 +174,6 @@ struct zs_size_stat { static struct dentry *zs_stat_root; #endif -#ifdef CONFIG_COMPACTION -static struct vfsmount *zsmalloc_mnt; -#endif - /* * We assign a page to ZS_ALMOST_EMPTY fullness group when: * n <= N / f, where @@ -252,7 +245,6 @@ struct zs_pool { struct dentry *stat_dentry; #endif #ifdef CONFIG_COMPACTION - struct inode *inode; struct work_struct free_work; #endif /* protect page/zspage migration */ @@ -271,6 +263,7 @@ struct zspage { unsigned int freeobj; struct page *first_page; struct list_head list; /* fullness list */ + struct zs_pool *pool; #ifdef CONFIG_COMPACTION rwlock_t lock; #endif @@ -295,8 +288,6 @@ static bool ZsHugePage(struct zspage *zspage) } #ifdef CONFIG_COMPACTION -static int zs_register_migration(struct zs_pool *pool); -static void zs_unregister_migration(struct zs_pool *pool); static void migrate_lock_init(struct zspage *zspage); static void migrate_read_lock(struct zspage *zspage); static void migrate_read_unlock(struct zspage *zspage); @@ -307,10 +298,6 @@ static void kick_deferred_free(struct zs_pool *pool); static void init_deferred_free(struct zs_pool *pool); static void SetZsPageMovable(struct zs_pool *pool, struct zspage *zspage); #else -static int zsmalloc_mount(void) { return 0; } -static void zsmalloc_unmount(void) {} -static int zs_register_migration(struct zs_pool *pool) { return 0; } -static void zs_unregister_migration(struct zs_pool *pool) {} static void migrate_lock_init(struct zspage *zspage) {} static void migrate_read_lock(struct zspage *zspage) {} static void migrate_read_unlock(struct zspage *zspage) {} @@ -1083,6 +1070,7 @@ static struct zspage *alloc_zspage(struct zs_pool *pool, create_page_chain(class, zspage, pages); init_zspage(class, zspage); + zspage->pool = pool; return zspage; } @@ -1754,33 +1742,6 @@ static void lock_zspage(struct zspage *zspage) migrate_read_unlock(zspage); } -static int zs_init_fs_context(struct fs_context *fc) -{ - return init_pseudo(fc, ZSMALLOC_MAGIC) ? 0 : -ENOMEM; -} - -static struct file_system_type zsmalloc_fs = { - .name = "zsmalloc", - .init_fs_context = zs_init_fs_context, - .kill_sb = kill_anon_super, -}; - -static int zsmalloc_mount(void) -{ - int ret = 0; - - zsmalloc_mnt = kern_mount(&zsmalloc_fs); - if (IS_ERR(zsmalloc_mnt)) - ret = PTR_ERR(zsmalloc_mnt); - - return ret; -} - -static void zsmalloc_unmount(void) -{ - kern_unmount(zsmalloc_mnt); -} - static void migrate_lock_init(struct zspage *zspage) { rwlock_init(&zspage->lock); @@ -1823,6 +1784,8 @@ static void dec_zspage_isolation(struct zspage *zspage) zspage->isolated--; } +static const struct movable_operations zsmalloc_mops; + static void replace_sub_page(struct size_class *class, struct zspage *zspage, struct page *newpage, struct page *oldpage) { @@ -1843,7 +1806,7 @@ static void replace_sub_page(struct size_class *class, struct zspage *zspage, set_first_obj_offset(newpage, get_first_obj_offset(oldpage)); if (unlikely(ZsHugePage(zspage))) newpage->index = oldpage->index; - __SetPageMovable(newpage, page_mapping(oldpage)); + __SetPageMovable(newpage, &zsmalloc_mops); } static bool zs_page_isolate(struct page *page, isolate_mode_t mode) @@ -1865,8 +1828,8 @@ static bool zs_page_isolate(struct page *page, isolate_mode_t mode) return true; } -static int zs_page_migrate(struct address_space *mapping, struct page *newpage, - struct page *page, enum migrate_mode mode) +static int zs_page_migrate(struct page *newpage, struct page *page, + enum migrate_mode mode) { struct zs_pool *pool; struct size_class *class; @@ -1889,14 +1852,15 @@ static int zs_page_migrate(struct address_space *mapping, struct page *newpage, VM_BUG_ON_PAGE(!PageMovable(page), page); VM_BUG_ON_PAGE(!PageIsolated(page), page); - pool = mapping->private_data; + /* The page is locked, so this pointer must remain valid */ + zspage = get_zspage(page); + pool = zspage->pool; /* * The pool migrate_lock protects the race between zpage migration * and zs_free. */ write_lock(&pool->migrate_lock); - zspage = get_zspage(page); class = zspage_class(pool, zspage); /* @@ -1964,31 +1928,12 @@ static void zs_page_putback(struct page *page) migrate_write_unlock(zspage); } -static const struct address_space_operations zsmalloc_aops = { +static const struct movable_operations zsmalloc_mops = { .isolate_page = zs_page_isolate, - .migratepage = zs_page_migrate, + .migrate_page = zs_page_migrate, .putback_page = zs_page_putback, }; -static int zs_register_migration(struct zs_pool *pool) -{ - pool->inode = alloc_anon_inode(zsmalloc_mnt->mnt_sb); - if (IS_ERR(pool->inode)) { - pool->inode = NULL; - return 1; - } - - pool->inode->i_mapping->private_data = pool; - pool->inode->i_mapping->a_ops = &zsmalloc_aops; - return 0; -} - -static void zs_unregister_migration(struct zs_pool *pool) -{ - flush_work(&pool->free_work); - iput(pool->inode); -} - /* * Caller should hold page_lock of all pages in the zspage * In here, we cannot use zspage meta data. @@ -2032,6 +1977,11 @@ static void kick_deferred_free(struct zs_pool *pool) schedule_work(&pool->free_work); } +static void zs_flush_migration(struct zs_pool *pool) +{ + flush_work(&pool->free_work); +} + static void init_deferred_free(struct zs_pool *pool) { INIT_WORK(&pool->free_work, async_free_zspage); @@ -2043,10 +1993,12 @@ static void SetZsPageMovable(struct zs_pool *pool, struct zspage *zspage) do { WARN_ON(!trylock_page(page)); - __SetPageMovable(page, pool->inode->i_mapping); + __SetPageMovable(page, &zsmalloc_mops); unlock_page(page); } while ((page = get_next_page(page)) != NULL); } +#else +static inline void zs_flush_migration(struct zs_pool *pool) { } #endif /* @@ -2324,9 +2276,6 @@ struct zs_pool *zs_create_pool(const char *name) /* debug only, don't abort if it fails */ zs_pool_stat_create(pool, name); - if (zs_register_migration(pool)) - goto err; - /* * Not critical since shrinker is only used to trigger internal * defragmentation of the pool which is pretty optional thing. If @@ -2348,7 +2297,7 @@ void zs_destroy_pool(struct zs_pool *pool) int i; zs_unregister_shrinker(pool); - zs_unregister_migration(pool); + zs_flush_migration(pool); zs_pool_stat_destroy(pool); for (i = 0; i < ZS_SIZE_CLASSES; i++) { @@ -2380,14 +2329,10 @@ static int __init zs_init(void) { int ret; - ret = zsmalloc_mount(); - if (ret) - goto out; - ret = cpuhp_setup_state(CPUHP_MM_ZS_PREPARE, "mm/zsmalloc:prepare", zs_cpu_prepare, zs_cpu_dead); if (ret) - goto hp_setup_fail; + goto out; #ifdef CONFIG_ZPOOL zpool_register_driver(&zs_zpool_driver); @@ -2397,8 +2342,6 @@ static int __init zs_init(void) return 0; -hp_setup_fail: - zsmalloc_unmount(); out: return ret; } @@ -2408,7 +2351,6 @@ static void __exit zs_exit(void) #ifdef CONFIG_ZPOOL zpool_unregister_driver(&zs_zpool_driver); #endif - zsmalloc_unmount(); cpuhp_remove_state(CPUHP_MM_ZS_PREPARE); zs_stat_exit(); -- cgit v1.3-8-gc7d7 From 541846502f4fe826cd7c16e4784695ac90736585 Mon Sep 17 00:00:00 2001 From: "Matthew Wilcox (Oracle)" Date: Mon, 6 Jun 2022 10:27:41 -0400 Subject: mm/migrate: Convert migrate_page() to migrate_folio() Convert all callers to pass a folio. Most have the folio already available. Switch all users from aops->migratepage to aops->migrate_folio. Also turn the documentation into kerneldoc. Signed-off-by: Matthew Wilcox (Oracle) Reviewed-by: Christoph Hellwig Acked-by: David Sterba --- drivers/gpu/drm/i915/gem/i915_gem_userptr.c | 4 ++-- fs/btrfs/disk-io.c | 2 +- fs/nfs/write.c | 2 +- include/linux/migrate.h | 5 ++-- mm/migrate.c | 37 ++++++++++++++++------------- mm/migrate_device.c | 3 ++- mm/shmem.c | 2 +- mm/swap_state.c | 2 +- 8 files changed, 30 insertions(+), 27 deletions(-) (limited to 'include/linux/migrate.h') diff --git a/drivers/gpu/drm/i915/gem/i915_gem_userptr.c b/drivers/gpu/drm/i915/gem/i915_gem_userptr.c index 094f06b4ce33..8423df021b71 100644 --- a/drivers/gpu/drm/i915/gem/i915_gem_userptr.c +++ b/drivers/gpu/drm/i915/gem/i915_gem_userptr.c @@ -216,8 +216,8 @@ i915_gem_userptr_put_pages(struct drm_i915_gem_object *obj, * However...! * * The mmu-notifier can be invalidated for a - * migrate_page, that is alreadying holding the lock - * on the page. Such a try_to_unmap() will result + * migrate_folio, that is alreadying holding the lock + * on the folio. Such a try_to_unmap() will result * in us calling put_pages() and so recursively try * to lock the page. We avoid that deadlock with * a trylock_page() and in exchange we risk missing diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c index 4aeb68f8450e..64d9299218f2 100644 --- a/fs/btrfs/disk-io.c +++ b/fs/btrfs/disk-io.c @@ -968,7 +968,7 @@ static int btree_migrate_folio(struct address_space *mapping, if (folio_get_private(src) && !filemap_release_folio(src, GFP_KERNEL)) return -EAGAIN; - return migrate_page(mapping, &dst->page, &src->page, mode); + return migrate_folio(mapping, dst, src, mode); } #else #define btree_migrate_folio NULL diff --git a/fs/nfs/write.c b/fs/nfs/write.c index 649b9e633459..69569696dde0 100644 --- a/fs/nfs/write.c +++ b/fs/nfs/write.c @@ -2139,7 +2139,7 @@ int nfs_migrate_folio(struct address_space *mapping, struct folio *dst, folio_wait_fscache(src); } - return migrate_page(mapping, &dst->page, &src->page, mode); + return migrate_folio(mapping, dst, src, mode); } #endif diff --git a/include/linux/migrate.h b/include/linux/migrate.h index 82c735ba6109..c9986d5da335 100644 --- a/include/linux/migrate.h +++ b/include/linux/migrate.h @@ -62,9 +62,8 @@ extern const char *migrate_reason_names[MR_TYPES]; #ifdef CONFIG_MIGRATION extern void putback_movable_pages(struct list_head *l); -extern int migrate_page(struct address_space *mapping, - struct page *newpage, struct page *page, - enum migrate_mode mode); +int migrate_folio(struct address_space *mapping, struct folio *dst, + struct folio *src, enum migrate_mode mode); extern int migrate_pages(struct list_head *l, new_page_t new, free_page_t free, unsigned long private, enum migrate_mode mode, int reason, unsigned int *ret_succeeded); diff --git a/mm/migrate.c b/mm/migrate.c index 61cd8d270b03..77aeb7e12f62 100644 --- a/mm/migrate.c +++ b/mm/migrate.c @@ -593,34 +593,37 @@ EXPORT_SYMBOL(folio_migrate_copy); * Migration functions ***********************************************************/ -/* - * Common logic to directly migrate a single LRU page suitable for - * pages that do not use PagePrivate/PagePrivate2. +/** + * migrate_folio() - Simple folio migration. + * @mapping: The address_space containing the folio. + * @dst: The folio to migrate the data to. + * @src: The folio containing the current data. + * @mode: How to migrate the page. * - * Pages are locked upon entry and exit. + * Common logic to directly migrate a single LRU folio suitable for + * folios that do not use PagePrivate/PagePrivate2. + * + * Folios are locked upon entry and exit. */ -int migrate_page(struct address_space *mapping, - struct page *newpage, struct page *page, - enum migrate_mode mode) +int migrate_folio(struct address_space *mapping, struct folio *dst, + struct folio *src, enum migrate_mode mode) { - struct folio *newfolio = page_folio(newpage); - struct folio *folio = page_folio(page); int rc; - BUG_ON(folio_test_writeback(folio)); /* Writeback must be complete */ + BUG_ON(folio_test_writeback(src)); /* Writeback must be complete */ - rc = folio_migrate_mapping(mapping, newfolio, folio, 0); + rc = folio_migrate_mapping(mapping, dst, src, 0); if (rc != MIGRATEPAGE_SUCCESS) return rc; if (mode != MIGRATE_SYNC_NO_COPY) - folio_migrate_copy(newfolio, folio); + folio_migrate_copy(dst, src); else - folio_migrate_flags(newfolio, folio); + folio_migrate_flags(dst, src); return MIGRATEPAGE_SUCCESS; } -EXPORT_SYMBOL(migrate_page); +EXPORT_SYMBOL(migrate_folio); #ifdef CONFIG_BLOCK /* Returns true if all buffers are successfully locked */ @@ -671,7 +674,7 @@ static int __buffer_migrate_folio(struct address_space *mapping, head = folio_buffers(src); if (!head) - return migrate_page(mapping, &dst->page, &src->page, mode); + return migrate_folio(mapping, dst, src, mode); /* Check whether page does not have extra refs before we do more work */ expected_count = folio_expected_refs(mapping, src); @@ -848,7 +851,7 @@ static int fallback_migrate_folio(struct address_space *mapping, !filemap_release_folio(src, GFP_KERNEL)) return mode == MIGRATE_SYNC ? -EAGAIN : -EBUSY; - return migrate_page(mapping, &dst->page, &src->page, mode); + return migrate_folio(mapping, dst, src, mode); } /* @@ -875,7 +878,7 @@ static int move_to_new_folio(struct folio *dst, struct folio *src, struct address_space *mapping = folio_mapping(src); if (!mapping) - rc = migrate_page(mapping, &dst->page, &src->page, mode); + rc = migrate_folio(mapping, dst, src, mode); else if (mapping->a_ops->migrate_folio) /* * Most folios have a mapping and most filesystems diff --git a/mm/migrate_device.c b/mm/migrate_device.c index 5052093d0262..5dd97c39ca6a 100644 --- a/mm/migrate_device.c +++ b/mm/migrate_device.c @@ -718,7 +718,8 @@ void migrate_vma_pages(struct migrate_vma *migrate) continue; } - r = migrate_page(mapping, newpage, page, MIGRATE_SYNC_NO_COPY); + r = migrate_folio(mapping, page_folio(newpage), + page_folio(page), MIGRATE_SYNC_NO_COPY); if (r != MIGRATEPAGE_SUCCESS) migrate->src[i] &= ~MIGRATE_PFN_MIGRATE; } diff --git a/mm/shmem.c b/mm/shmem.c index 28a62be1d41e..15c61456e087 100644 --- a/mm/shmem.c +++ b/mm/shmem.c @@ -3801,7 +3801,7 @@ const struct address_space_operations shmem_aops = { .write_end = shmem_write_end, #endif #ifdef CONFIG_MIGRATION - .migratepage = migrate_page, + .migrate_folio = migrate_folio, #endif .error_remove_page = shmem_error_remove_page, }; diff --git a/mm/swap_state.c b/mm/swap_state.c index f5b6f5638908..0a2021fc55ad 100644 --- a/mm/swap_state.c +++ b/mm/swap_state.c @@ -33,7 +33,7 @@ static const struct address_space_operations swap_aops = { .writepage = swap_writepage, .dirty_folio = noop_dirty_folio, #ifdef CONFIG_MIGRATION - .migratepage = migrate_page, + .migrate_folio = migrate_folio, #endif }; -- cgit v1.3-8-gc7d7 From b890ec2a2c2d962f71ba31ae291f8fd252b46258 Mon Sep 17 00:00:00 2001 From: "Matthew Wilcox (Oracle)" Date: Mon, 6 Jun 2022 10:47:21 -0400 Subject: hugetlb: Convert to migrate_folio This involves converting migrate_huge_page_move_mapping(). We also need a folio variant of hugetlb_set_page_subpool(), but that's for a later patch. Signed-off-by: Matthew Wilcox (Oracle) Acked-by: Muchun Song Reviewed-by: Mike Kravetz --- fs/hugetlbfs/inode.c | 23 ++++++++++++++--------- include/linux/migrate.h | 6 +++--- mm/migrate.c | 18 +++++++++--------- 3 files changed, 26 insertions(+), 21 deletions(-) (limited to 'include/linux/migrate.h') diff --git a/fs/hugetlbfs/inode.c b/fs/hugetlbfs/inode.c index 14d33f725e05..eca1d0fabd7e 100644 --- a/fs/hugetlbfs/inode.c +++ b/fs/hugetlbfs/inode.c @@ -954,28 +954,33 @@ static int hugetlbfs_symlink(struct user_namespace *mnt_userns, return error; } -static int hugetlbfs_migrate_page(struct address_space *mapping, - struct page *newpage, struct page *page, +#ifdef CONFIG_MIGRATION +static int hugetlbfs_migrate_folio(struct address_space *mapping, + struct folio *dst, struct folio *src, enum migrate_mode mode) { int rc; - rc = migrate_huge_page_move_mapping(mapping, newpage, page); + rc = migrate_huge_page_move_mapping(mapping, dst, src); if (rc != MIGRATEPAGE_SUCCESS) return rc; - if (hugetlb_page_subpool(page)) { - hugetlb_set_page_subpool(newpage, hugetlb_page_subpool(page)); - hugetlb_set_page_subpool(page, NULL); + if (hugetlb_page_subpool(&src->page)) { + hugetlb_set_page_subpool(&dst->page, + hugetlb_page_subpool(&src->page)); + hugetlb_set_page_subpool(&src->page, NULL); } if (mode != MIGRATE_SYNC_NO_COPY) - migrate_page_copy(newpage, page); + folio_migrate_copy(dst, src); else - migrate_page_states(newpage, page); + folio_migrate_flags(dst, src); return MIGRATEPAGE_SUCCESS; } +#else +#define hugetlbfs_migrate_folio NULL +#endif static int hugetlbfs_error_remove_page(struct address_space *mapping, struct page *page) @@ -1142,7 +1147,7 @@ static const struct address_space_operations hugetlbfs_aops = { .write_begin = hugetlbfs_write_begin, .write_end = hugetlbfs_write_end, .dirty_folio = noop_dirty_folio, - .migratepage = hugetlbfs_migrate_page, + .migrate_folio = hugetlbfs_migrate_folio, .error_remove_page = hugetlbfs_error_remove_page, }; diff --git a/include/linux/migrate.h b/include/linux/migrate.h index c9986d5da335..13f793309b75 100644 --- a/include/linux/migrate.h +++ b/include/linux/migrate.h @@ -72,8 +72,8 @@ extern int isolate_movable_page(struct page *page, isolate_mode_t mode); extern void migrate_page_states(struct page *newpage, struct page *page); extern void migrate_page_copy(struct page *newpage, struct page *page); -extern int migrate_huge_page_move_mapping(struct address_space *mapping, - struct page *newpage, struct page *page); +int migrate_huge_page_move_mapping(struct address_space *mapping, + struct folio *dst, struct folio *src); extern int migrate_page_move_mapping(struct address_space *mapping, struct page *newpage, struct page *page, int extra_count); void migration_entry_wait_on_locked(swp_entry_t entry, pte_t *ptep, @@ -104,7 +104,7 @@ static inline void migrate_page_copy(struct page *newpage, struct page *page) {} static inline int migrate_huge_page_move_mapping(struct address_space *mapping, - struct page *newpage, struct page *page) + struct folio *dst, struct folio *src) { return -ENOSYS; } diff --git a/mm/migrate.c b/mm/migrate.c index 4ed8f0d53c77..0dd3ec9525b3 100644 --- a/mm/migrate.c +++ b/mm/migrate.c @@ -474,26 +474,26 @@ EXPORT_SYMBOL(folio_migrate_mapping); * of folio_migrate_mapping(). */ int migrate_huge_page_move_mapping(struct address_space *mapping, - struct page *newpage, struct page *page) + struct folio *dst, struct folio *src) { - XA_STATE(xas, &mapping->i_pages, page_index(page)); + XA_STATE(xas, &mapping->i_pages, folio_index(src)); int expected_count; xas_lock_irq(&xas); - expected_count = 2 + page_has_private(page); - if (!page_ref_freeze(page, expected_count)) { + expected_count = 2 + folio_has_private(src); + if (!folio_ref_freeze(src, expected_count)) { xas_unlock_irq(&xas); return -EAGAIN; } - newpage->index = page->index; - newpage->mapping = page->mapping; + dst->index = src->index; + dst->mapping = src->mapping; - get_page(newpage); + folio_get(dst); - xas_store(&xas, newpage); + xas_store(&xas, dst); - page_ref_unfreeze(page, expected_count - 1); + folio_ref_unfreeze(src, expected_count - 1); xas_unlock_irq(&xas); -- cgit v1.3-8-gc7d7 From 9800562f2ab41656b0bdc2a41c77ab3f6dfdd6fc Mon Sep 17 00:00:00 2001 From: "Matthew Wilcox (Oracle)" Date: Mon, 6 Jun 2022 13:29:10 -0400 Subject: mm/folio-compat: Remove migration compatibility functions migrate_page_move_mapping(), migrate_page_copy() and migrate_page_states() are all now unused after converting all the filesystems from aops->migratepage() to aops->migrate_folio(). Signed-off-by: Matthew Wilcox (Oracle) Reviewed-by: Christoph Hellwig --- include/linux/migrate.h | 11 ----------- mm/folio-compat.c | 22 ---------------------- mm/ksm.c | 2 +- 3 files changed, 1 insertion(+), 34 deletions(-) (limited to 'include/linux/migrate.h') diff --git a/include/linux/migrate.h b/include/linux/migrate.h index 13f793309b75..ae5bb67a9ba1 100644 --- a/include/linux/migrate.h +++ b/include/linux/migrate.h @@ -70,12 +70,8 @@ extern int migrate_pages(struct list_head *l, new_page_t new, free_page_t free, extern struct page *alloc_migration_target(struct page *page, unsigned long private); extern int isolate_movable_page(struct page *page, isolate_mode_t mode); -extern void migrate_page_states(struct page *newpage, struct page *page); -extern void migrate_page_copy(struct page *newpage, struct page *page); int migrate_huge_page_move_mapping(struct address_space *mapping, struct folio *dst, struct folio *src); -extern int migrate_page_move_mapping(struct address_space *mapping, - struct page *newpage, struct page *page, int extra_count); void migration_entry_wait_on_locked(swp_entry_t entry, pte_t *ptep, spinlock_t *ptl); void folio_migrate_flags(struct folio *newfolio, struct folio *folio); @@ -96,13 +92,6 @@ static inline struct page *alloc_migration_target(struct page *page, static inline int isolate_movable_page(struct page *page, isolate_mode_t mode) { return -EBUSY; } -static inline void migrate_page_states(struct page *newpage, struct page *page) -{ -} - -static inline void migrate_page_copy(struct page *newpage, - struct page *page) {} - static inline int migrate_huge_page_move_mapping(struct address_space *mapping, struct folio *dst, struct folio *src) { diff --git a/mm/folio-compat.c b/mm/folio-compat.c index 20bc15b57d93..458618c7302c 100644 --- a/mm/folio-compat.c +++ b/mm/folio-compat.c @@ -51,28 +51,6 @@ void mark_page_accessed(struct page *page) } EXPORT_SYMBOL(mark_page_accessed); -#ifdef CONFIG_MIGRATION -int migrate_page_move_mapping(struct address_space *mapping, - struct page *newpage, struct page *page, int extra_count) -{ - return folio_migrate_mapping(mapping, page_folio(newpage), - page_folio(page), extra_count); -} -EXPORT_SYMBOL(migrate_page_move_mapping); - -void migrate_page_states(struct page *newpage, struct page *page) -{ - folio_migrate_flags(page_folio(newpage), page_folio(page)); -} -EXPORT_SYMBOL(migrate_page_states); - -void migrate_page_copy(struct page *newpage, struct page *page) -{ - folio_migrate_copy(page_folio(newpage), page_folio(page)); -} -EXPORT_SYMBOL(migrate_page_copy); -#endif - bool set_page_writeback(struct page *page) { return folio_start_writeback(page_folio(page)); diff --git a/mm/ksm.c b/mm/ksm.c index 54f78c9eecae..e8f8c1a2bb39 100644 --- a/mm/ksm.c +++ b/mm/ksm.c @@ -712,7 +712,7 @@ again: * however, it might mean that the page is under page_ref_freeze(). * The __remove_mapping() case is easy, again the node is now stale; * the same is in reuse_ksm_page() case; but if page is swapcache - * in migrate_page_move_mapping(), it might still be our page, + * in folio_migrate_mapping(), it might still be our page, * in which case it's essential to keep the node. */ while (!get_page_unless_zero(page)) { -- cgit v1.3-8-gc7d7