[13/15] mm, devmap: introduce CONFIG_DEVMAP_MANAGED_PAGES

Message ID	150949216597.24061.3943310722702629588.stgit@dwillia2-desk3.amr.corp.intel.com (mailing list archive)
State	New, archived
Headers	show Return-Path: <linux-nvdimm-bounces@lists.01.org> Received-SPF: Pass (sender SPF authorized) identity=mailfrom; client-ip=134.134.136.24; helo=mga09.intel.com; envelope-from=dan.j.williams@intel.com; receiver=linux-nvdimm@lists.01.org Subject: [PATCH 13/15] mm, devmap: introduce CONFIG_DEVMAP_MANAGED_PAGES From: Dan Williams <dan.j.williams@intel.com> To: linux-nvdimm@lists.01.org Date: Tue, 31 Oct 2017 16:22:46 -0700 Message-ID: <150949216597.24061.3943310722702629588.stgit@dwillia2-desk3.amr.corp.intel.com> In-Reply-To: <150949209290.24061.6283157778959640151.stgit@dwillia2-desk3.amr.corp.intel.com> References: <150949209290.24061.6283157778959640151.stgit@dwillia2-desk3.amr.corp.intel.com> User-Agent: StGit/0.17.1-9-g687f MIME-Version: 1.0 Precedence: list Cc: Michal Hocko <mhocko@suse.com>, linux-kernel@vger.kernel.org, linux-xfs@vger.kernel.org, linux-mm@kvack.org, =?utf-8?b?SsOpcsO0bWU=?= Glisse <jglisse@redhat.com>, linux-fsdevel@vger.kernel.org, akpm@linux-foundation.org, hch@lst.de Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: base64 Errors-To: linux-nvdimm-bounces@lists.01.org Sender: "Linux-nvdimm" <linux-nvdimm-bounces@lists.01.org>

diff --git a/drivers/dax/super.c b/drivers/dax/super.c index 193e0cd8d90c..4ac359e14777 100644 --- a/drivers/dax/super.c +++ b/drivers/dax/super.c @@ -190,6 +190,7 @@ struct dax_device *fs_dax_claim_bdev(struct block_device *bdev, void *owner) return NULL; } + devmap_managed_pages_enable(); pgmap->type = MEMORY_DEVICE_FS_DAX; pgmap->page_free = generic_dax_pagefree; pgmap->data = owner; @@ -214,6 +215,7 @@ void fs_dax_release(struct dax_device *dax_dev, void *owner) pgmap->type = MEMORY_DEVICE_HOST; pgmap->page_free = NULL; pgmap->data = NULL; + devmap_managed_pages_disable(); mutex_unlock(&devmap_lock); } EXPORT_SYMBOL_GPL(fs_dax_release); diff --git a/fs/Kconfig b/fs/Kconfig index b40128bf6d1a..cd4ee17ecdd8 100644 --- a/fs/Kconfig +++ b/fs/Kconfig @@ -38,6 +38,7 @@ config FS_DAX bool "Direct Access (DAX) support" depends on MMU depends on !(ARM || MIPS || SPARC) + select DEVMAP_MANAGED_PAGES select FS_IOMAP select DAX help diff --git a/include/linux/memremap.h b/include/linux/memremap.h index 39d2de3f744b..a6716f5335e7 100644 --- a/include/linux/memremap.h +++ b/include/linux/memremap.h @@ -1,6 +1,5 @@ #ifndef _LINUX_MEMREMAP_H_ #define _LINUX_MEMREMAP_H_ -#include <linux/mm.h> #include <linux/ioport.h> #include <linux/percpu-refcount.h> @@ -138,6 +137,9 @@ struct dev_pagemap { enum memory_type type; }; +void devmap_managed_pages_enable(void); +void devmap_managed_pages_disable(void); + #ifdef CONFIG_ZONE_DEVICE void *devm_memremap_pages(struct device *dev, struct resource *res, struct percpu_ref *ref, struct vmem_altmap *altmap); @@ -164,7 +166,7 @@ static inline struct dev_pagemap *find_dev_pagemap(resource_size_t phys) } #endif -#if defined(CONFIG_DEVICE_PRIVATE) || defined(CONFIG_DEVICE_PUBLIC) +#ifdef CONFIG_DEVMAP_MANAGED_PAGES static inline bool is_device_private_page(const struct page *page) { return is_zone_device_page(page) && @@ -176,7 +178,17 @@ static inline bool is_device_public_page(const struct page *page) return is_zone_device_page(page) && page->pgmap->type == MEMORY_DEVICE_PUBLIC; } -#endif /* CONFIG_DEVICE_PRIVATE || CONFIG_DEVICE_PUBLIC */ +#else /* CONFIG_DEVMAP_MANAGED_PAGES */ +static inline bool is_device_private_page(const struct page *page) +{ + return false; +} + +static inline bool is_device_public_page(const struct page *page) +{ + return false; +} +#endif /* CONFIG_DEVMAP_MANAGED_PAGES */ /** * get_dev_pagemap() - take a new live reference on the dev_pagemap for @pfn diff --git a/include/linux/mm.h b/include/linux/mm.h index 8c1e3ac77285..2d6cf2583e10 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -800,27 +800,32 @@ static inline bool is_zone_device_page(const struct page *page) } #endif -#if defined(CONFIG_DEVICE_PRIVATE) || defined(CONFIG_DEVICE_PUBLIC) -void put_zone_device_private_or_public_page(struct page *page); -DECLARE_STATIC_KEY_FALSE(device_private_key); -#define IS_HMM_ENABLED static_branch_unlikely(&device_private_key) -static inline bool is_device_private_page(const struct page *page); -static inline bool is_device_public_page(const struct page *page); -#else /* CONFIG_DEVICE_PRIVATE || CONFIG_DEVICE_PUBLIC */ -static inline void put_zone_device_private_or_public_page(struct page *page) -{ -} -#define IS_HMM_ENABLED 0 -static inline bool is_device_private_page(const struct page *page) +#ifdef CONFIG_DEVMAP_MANAGED_PAGES +void __put_devmap_managed_page(struct page *page); +DECLARE_STATIC_KEY_FALSE(devmap_managed_key); +static inline bool put_devmap_managed_page(struct page *page) { + if (!static_branch_unlikely(&devmap_managed_key)) + return false; + if (!is_zone_device_page(page)) + return false; + switch (page->pgmap->type) { + case MEMORY_DEVICE_PRIVATE: + case MEMORY_DEVICE_PUBLIC: + case MEMORY_DEVICE_FS_DAX: + __put_devmap_managed_page(page); + return true; + default: + break; + } return false; } -static inline bool is_device_public_page(const struct page *page) +#else /* CONFIG_DEVMAP_MANAGED_PAGES */ +static inline bool put_devmap_managed_page(struct page *page) { return false; } -#endif /* CONFIG_DEVICE_PRIVATE || CONFIG_DEVICE_PUBLIC */ - +#endif /* CONFIG_DEVMAP_MANAGED_PAGES */ static inline void get_page(struct page *page) { @@ -838,16 +843,13 @@ static inline void put_page(struct page *page) page = compound_head(page); /* - * For private device pages we need to catch refcount transition from - * 2 to 1, when refcount reach one it means the private device page is - * free and we need to inform the device driver through callback. See + * For devmap managed pages we need to catch refcount transition from + * 2 to 1, when refcount reach one it means the page is free and we + * need to inform the device driver through callback. See * include/linux/memremap.h and HMM for details. */ - if (IS_HMM_ENABLED && unlikely(is_device_private_page(page) || - unlikely(is_device_public_page(page)))) { - put_zone_device_private_or_public_page(page); + if (put_devmap_managed_page(page)) return; - } if (put_page_testzero(page)) __put_page(page); diff --git a/kernel/memremap.c b/kernel/memremap.c index bf61cfa89c7d..8a4ebfe9db4e 100644 --- a/kernel/memremap.c +++ b/kernel/memremap.c @@ -503,9 +503,26 @@ struct vmem_altmap *to_vmem_altmap(unsigned long memmap_start) } #endif /* CONFIG_ZONE_DEVICE */ +#ifdef CONFIG_DEVMAP_MANAGED_PAGES +DEFINE_STATIC_KEY_FALSE(devmap_managed_key); +EXPORT_SYMBOL(devmap_managed_key); +static atomic_t devmap_enable; -#if IS_ENABLED(CONFIG_DEVICE_PRIVATE) || IS_ENABLED(CONFIG_DEVICE_PUBLIC) -void put_zone_device_private_or_public_page(struct page *page) +void devmap_managed_pages_enable(void) +{ + if (atomic_inc_return(&devmap_enable) == 1) + static_branch_enable(&devmap_managed_key); +} +EXPORT_SYMBOL(devmap_managed_pages_enable); + +void devmap_managed_pages_disable(void) +{ + if (atomic_dec_and_test(&devmap_enable)) + static_branch_disable(&devmap_managed_key); +} +EXPORT_SYMBOL(devmap_managed_pages_disable); + +void __put_devmap_managed_page(struct page *page) { int count = page_ref_dec_return(page); @@ -525,5 +542,5 @@ void put_zone_device_private_or_public_page(struct page *page) } else if (!count) __put_page(page); } -EXPORT_SYMBOL(put_zone_device_private_or_public_page); -#endif /* CONFIG_DEVICE_PRIVATE || CONFIG_DEVICE_PUBLIC */ +EXPORT_SYMBOL(__put_devmap_managed_page); +#endif /* CONFIG_DEVMAP_MANAGED_PAGES */ diff --git a/mm/Kconfig b/mm/Kconfig index 9c4bdddd80c2..8ee95197dc9f 100644 --- a/mm/Kconfig +++ b/mm/Kconfig @@ -705,6 +705,9 @@ config ARCH_HAS_HMM config MIGRATE_VMA_HELPER bool +config DEVMAP_MANAGED_PAGES + bool + config HMM bool select MIGRATE_VMA_HELPER @@ -725,6 +728,7 @@ config DEVICE_PRIVATE bool "Unaddressable device memory (GPU memory, ...)" depends on ARCH_HAS_HMM select HMM + select DEVMAP_MANAGED_PAGES help Allows creation of struct pages to represent unaddressable device @@ -735,6 +739,7 @@ config DEVICE_PUBLIC bool "Addressable device memory (like GPU memory)" depends on ARCH_HAS_HMM select HMM + select DEVMAP_MANAGED_PAGES help Allows creation of struct pages to represent addressable device diff --git a/mm/hmm.c b/mm/hmm.c index a88a847bccba..53c8f1dd821d 100644 --- a/mm/hmm.c +++ b/mm/hmm.c @@ -35,15 +35,6 @@ #define PA_SECTION_SIZE (1UL << PA_SECTION_SHIFT) -#if defined(CONFIG_DEVICE_PRIVATE) || defined(CONFIG_DEVICE_PUBLIC) -/* - * Device private memory see HMM (Documentation/vm/hmm.txt) or hmm.h - */ -DEFINE_STATIC_KEY_FALSE(device_private_key); -EXPORT_SYMBOL(device_private_key); -#endif /* CONFIG_DEVICE_PRIVATE || CONFIG_DEVICE_PUBLIC */ - - #if IS_ENABLED(CONFIG_HMM_MIRROR) static const struct mmu_notifier_ops hmm_mmu_notifier_ops; @@ -998,7 +989,7 @@ struct hmm_devmem *hmm_devmem_add(const struct hmm_devmem_ops *ops, resource_size_t addr; int ret; - static_branch_enable(&device_private_key); + devmap_managed_pages_enable(); devmem = devres_alloc_node(&hmm_devmem_release, sizeof(*devmem), GFP_KERNEL, dev_to_node(device)); @@ -1092,7 +1083,7 @@ struct hmm_devmem *hmm_devmem_add_resource(const struct hmm_devmem_ops *ops, if (res->desc != IORES_DESC_DEVICE_PUBLIC_MEMORY) return ERR_PTR(-EINVAL); - static_branch_enable(&device_private_key); + devmap_managed_pages_enable(); devmem = devres_alloc_node(&hmm_devmem_release, sizeof(*devmem), GFP_KERNEL, dev_to_node(device)); diff --git a/mm/swap.c b/mm/swap.c index a77d68f2c1b6..09c71044b565 100644 --- a/mm/swap.c +++ b/mm/swap.c @@ -29,6 +29,7 @@ #include <linux/cpu.h> #include <linux/notifier.h> #include <linux/backing-dev.h> +#include <linux/memremap.h> #include <linux/memcontrol.h> #include <linux/gfp.h> #include <linux/uio.h> @@ -772,7 +773,7 @@ void release_pages(struct page **pages, int nr, bool cold) flags); locked_pgdat = NULL; } - put_zone_device_private_or_public_page(page); + put_devmap_managed_page(page); continue; }

[13/15] mm, devmap: introduce CONFIG_DEVMAP_MANAGED_PAGES

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