Add zpool api. zpool provides an interface for memory storage, typically of compressed memory. Users can select what backend to use; currently the only implementations are zbud, a low density implementation with up to two compressed pages per storage page, and zsmalloc, a higher density implementation with multiple compressed pages per storage page.
Signed-off-by: Dan Streetman <ddstr...@ieee.org> Cc: Seth Jennings <sjenni...@variantweb.net> Cc: Minchan Kim <minc...@kernel.org> Cc: Nitin Gupta <ngu...@vflare.org> Cc: Weijie Yang <weijie.y...@samsung.com> --- Changes since v1 https://lkml.org/lkml/2014/4/19/101 -add some pr_info() during creation and pr_err() on errors -remove zpool code to call zs_shrink(), since zsmalloc shrinking was removed from this patchset -remove fallback; only specified pool type will be tried -pr_fmt() is defined in zpool to prefix zpool: in any pr_XXX() calls include/linux/zpool.h | 160 +++++++++++++++++++++++ mm/Kconfig | 43 ++++--- mm/Makefile | 1 + mm/zpool.c | 349 ++++++++++++++++++++++++++++++++++++++++++++++++++ 4 files changed, 535 insertions(+), 18 deletions(-) create mode 100644 include/linux/zpool.h create mode 100644 mm/zpool.c diff --git a/include/linux/zpool.h b/include/linux/zpool.h new file mode 100644 index 0000000..08f5468 --- /dev/null +++ b/include/linux/zpool.h @@ -0,0 +1,160 @@ +/* + * zpool memory storage api + * + * Copyright (C) 2014 Dan Streetman + * + * This is a common frontend for the zbud and zsmalloc memory + * storage pool implementations. Typically, this is used to + * store compressed memory. + */ + +#ifndef _ZPOOL_H_ +#define _ZPOOL_H_ + +struct zpool; + +struct zpool_ops { + int (*evict)(struct zpool *pool, unsigned long handle); +}; + +#define ZPOOL_TYPE_ZSMALLOC "zsmalloc" +#define ZPOOL_TYPE_ZBUD "zbud" + +/* + * Control how a handle is mapped. It will be ignored if the + * implementation does not support it. Its use is optional. + * Note that this does not refer to memory protection, it + * refers to how the memory will be copied in/out if copying + * is necessary during mapping; read-write is the safest as + * it copies the existing memory in on map, and copies the + * changed memory back out on unmap. Write-only does not copy + * in the memory and should only be used for initialization. + * If in doubt, use ZPOOL_MM_DEFAULT which is read-write. + */ +enum zpool_mapmode { + ZPOOL_MM_RW, /* normal read-write mapping */ + ZPOOL_MM_RO, /* read-only (no copy-out at unmap time) */ + ZPOOL_MM_WO, /* write-only (no copy-in at map time) */ + + ZPOOL_MM_DEFAULT = ZPOOL_MM_RW +}; + +/** + * zpool_create_pool() - Create a new zpool + * @type The type of the zpool to create (e.g. zbud, zsmalloc) + * @flags What GFP flags should be used when the zpool allocates memory. + * @ops The optional ops callback. + * + * This creates a new zpool of the specified type. The zpool will use the + * given flags when allocating any memory. If the ops param is NULL, then + * the created zpool will not be shrinkable. + * + * Returns: New zpool on success, NULL on failure. + */ +struct zpool *zpool_create_pool(char *type, gfp_t flags, + struct zpool_ops *ops); + +/** + * zpool_get_type() - Get the type of the zpool + * @pool The zpool to check + * + * This returns the type of the pool, which will match one of the + * ZPOOL_TYPE_* defined values. + * + * Returns: The type of zpool. + */ +char *zpool_get_type(struct zpool *pool); + +/** + * zpool_destroy_pool() - Destroy a zpool + * @pool The zpool to destroy. + * + * This destroys an existing zpool. The zpool should not be in use. + */ +void zpool_destroy_pool(struct zpool *pool); + +/** + * zpool_malloc() - Allocate memory + * @pool The zpool to allocate from. + * @size The amount of memory to allocate. + * @handle Pointer to the handle to set + * + * This allocates the requested amount of memory from the pool. + * The provided @handle will be set to the allocated object handle. + * + * Returns: 0 on success, negative value on error. + */ +int zpool_malloc(struct zpool *pool, size_t size, unsigned long *handle); + +/** + * zpool_free() - Free previously allocated memory + * @pool The zpool that allocated the memory. + * @handle The handle to the memory to free. + * + * This frees previously allocated memory. This does not guarantee + * that the pool will actually free memory, only that the memory + * in the pool will become available for use by the pool. + */ +void zpool_free(struct zpool *pool, unsigned long handle); + +/** + * zpool_shrink() - Shrink the pool size + * @pool The zpool to shrink. + * @size The minimum amount to shrink the pool. + * + * This attempts to shrink the actual memory size of the pool + * by evicting currently used handle(s). If the pool was + * created with no zpool_ops, or the evict call fails for any + * of the handles, this will fail. + * + * Returns: 0 on success, negative value on error/failure. + */ +int zpool_shrink(struct zpool *pool, size_t size); + +/** + * zpool_map_handle() - Map a previously allocated handle into memory + * @pool The zpool that the handle was allocated from + * @handle The handle to map + * @mm How the memory should be mapped + * + * This maps a previously allocated handle into memory. The @mm + * param indicates to the implemenation how the memory will be + * used, i.e. read-only, write-only, read-write. If the + * implementation does not support it, the memory will be treated + * as read-write. + * + * This may hold locks, disable interrupts, and/or preemption, + * and the zpool_unmap_handle() must be called to undo those + * actions. The code that uses the mapped handle should complete + * its operatons on the mapped handle memory quickly and unmap + * as soon as possible. Multiple handles should not be mapped + * concurrently on a cpu. + * + * Returns: A pointer to the handle's mapped memory area. + */ +void *zpool_map_handle(struct zpool *pool, unsigned long handle, + enum zpool_mapmode mm); + +/** + * zpool_unmap_handle() - Unmap a previously mapped handle + * @pool The zpool that the handle was allocated from + * @handle The handle to unmap + * + * This unmaps a previously mapped handle. Any locks or other + * actions that the implemenation took in zpool_map_handle() + * will be undone here. The memory area returned from + * zpool_map_handle() should no longer be used after this. + */ +void zpool_unmap_handle(struct zpool *pool, unsigned long handle); + +/** + * zpool_get_total_size() - The total size of the pool + * @pool The zpool to check + * + * This returns the total size in bytes of the pool. + * + * Returns: Total size of the zpool in bytes. + */ +u64 zpool_get_total_size(struct zpool *pool); + +#endif diff --git a/mm/Kconfig b/mm/Kconfig index 30cb6cb..bdb4cb2 100644 --- a/mm/Kconfig +++ b/mm/Kconfig @@ -515,21 +515,23 @@ config CMA_DEBUG processing calls such as dma_alloc_from_contiguous(). This option does not affect warning and error messages. -config ZBUD - tristate - default n +config MEM_SOFT_DIRTY + bool "Track memory changes" + depends on CHECKPOINT_RESTORE && HAVE_ARCH_SOFT_DIRTY && PROC_FS + select PROC_PAGE_MONITOR help - A special purpose allocator for storing compressed pages. - It is designed to store up to two compressed pages per physical - page. While this design limits storage density, it has simple and - deterministic reclaim properties that make it preferable to a higher - density approach when reclaim will be used. + This option enables memory changes tracking by introducing a + soft-dirty bit on pte-s. This bit it set when someone writes + into a page just as regular dirty bit, but unlike the latter + it can be cleared by hands. + + See Documentation/vm/soft-dirty.txt for more details. config ZSWAP bool "Compressed cache for swap pages (EXPERIMENTAL)" depends on FRONTSWAP && CRYPTO=y select CRYPTO_LZO - select ZBUD + select ZPOOL default n help A lightweight compressed cache for swap pages. It takes @@ -545,17 +547,22 @@ config ZSWAP they have not be fully explored on the large set of potential configurations and workloads that exist. -config MEM_SOFT_DIRTY - bool "Track memory changes" - depends on CHECKPOINT_RESTORE && HAVE_ARCH_SOFT_DIRTY && PROC_FS - select PROC_PAGE_MONITOR +config ZPOOL + tristate "Common API for compressed memory storage" + default n help - This option enables memory changes tracking by introducing a - soft-dirty bit on pte-s. This bit it set when someone writes - into a page just as regular dirty bit, but unlike the latter - it can be cleared by hands. + Compressed memory storage API. This allows using either zbud or + zsmalloc. - See Documentation/vm/soft-dirty.txt for more details. +config ZBUD + tristate "Low density storage for compressed pages" + default n + help + A special purpose allocator for storing compressed pages. + It is designed to store up to two compressed pages per physical + page. While this design limits storage density, it has simple and + deterministic reclaim properties that make it preferable to a higher + density approach when reclaim will be used. config ZSMALLOC bool "Memory allocator for compressed pages" diff --git a/mm/Makefile b/mm/Makefile index 9b75a4d..f64a5d4 100644 --- a/mm/Makefile +++ b/mm/Makefile @@ -61,6 +61,7 @@ obj-$(CONFIG_DEBUG_KMEMLEAK_TEST) += kmemleak-test.o obj-$(CONFIG_CLEANCACHE) += cleancache.o obj-$(CONFIG_MEMORY_ISOLATION) += page_isolation.o obj-$(CONFIG_PAGE_OWNER) += pageowner.o +obj-$(CONFIG_ZPOOL) += zpool.o obj-$(CONFIG_ZBUD) += zbud.o obj-$(CONFIG_ZSMALLOC) += zsmalloc.o obj-$(CONFIG_GENERIC_EARLY_IOREMAP) += early_ioremap.o diff --git a/mm/zpool.c b/mm/zpool.c new file mode 100644 index 0000000..2bda300 --- /dev/null +++ b/mm/zpool.c @@ -0,0 +1,349 @@ +/* + * zpool memory storage api + * + * Copyright (C) 2014 Dan Streetman + * + * This is a common frontend for the zbud and zsmalloc memory + * storage pool implementations. Typically, this is used to + * store compressed memory. + */ + +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt + +#include <linux/list.h> +#include <linux/types.h> +#include <linux/mm.h> +#include <linux/slab.h> +#include <linux/spinlock.h> +#include <linux/zpool.h> +#include <linux/zbud.h> +#include <linux/zsmalloc.h> + +struct zpool_imp { + void (*destroy)(struct zpool *pool); + + int (*malloc)(struct zpool *pool, size_t size, unsigned long *handle); + void (*free)(struct zpool *pool, unsigned long handle); + + int (*shrink)(struct zpool *pool, size_t size); + + void *(*map)(struct zpool *pool, unsigned long handle, + enum zpool_mapmode mm); + void (*unmap)(struct zpool *pool, unsigned long handle); + + u64 (*total_size)(struct zpool *pool); +}; + +struct zpool { + char *type; + + union { +#ifdef CONFIG_ZSMALLOC + struct zs_pool *zsmalloc_pool; +#endif +#ifdef CONFIG_ZBUD + struct zbud_pool *zbud_pool; +#endif + }; + + struct zpool_imp *imp; + struct zpool_ops *ops; + + struct list_head list; +}; + +static LIST_HEAD(zpools); +static DEFINE_SPINLOCK(zpools_lock); + +static int zpool_noop_evict(struct zpool *pool, unsigned long handle) +{ + return -EINVAL; +} +static struct zpool_ops zpool_noop_ops = { + .evict = zpool_noop_evict +}; + + +/* zsmalloc */ + +#ifdef CONFIG_ZSMALLOC + +static void zpool_zsmalloc_destroy(struct zpool *zpool) +{ + spin_lock(&zpools_lock); + list_del(&zpool->list); + spin_unlock(&zpools_lock); + + zs_destroy_pool(zpool->zsmalloc_pool); + kfree(zpool); +} + +static int zpool_zsmalloc_malloc(struct zpool *pool, size_t size, + unsigned long *handle) +{ + *handle = zs_malloc(pool->zsmalloc_pool, size); + return *handle ? 0 : -1; +} + +static void zpool_zsmalloc_free(struct zpool *pool, unsigned long handle) +{ + zs_free(pool->zsmalloc_pool, handle); +} + +static int zpool_zsmalloc_shrink(struct zpool *pool, size_t size) +{ + /* Not yet supported */ + return -EINVAL; +} + +static void *zpool_zsmalloc_map(struct zpool *pool, unsigned long handle, + enum zpool_mapmode zpool_mapmode) +{ + enum zs_mapmode zs_mapmode; + + switch (zpool_mapmode) { + case ZPOOL_MM_RO: + zs_mapmode = ZS_MM_RO; break; + case ZPOOL_MM_WO: + zs_mapmode = ZS_MM_WO; break; + case ZPOOL_MM_RW: /* fallthrough */ + default: + zs_mapmode = ZS_MM_RW; break; + } + return zs_map_object(pool->zsmalloc_pool, handle, zs_mapmode); +} + +static void zpool_zsmalloc_unmap(struct zpool *pool, unsigned long handle) +{ + zs_unmap_object(pool->zsmalloc_pool, handle); +} + +static u64 zpool_zsmalloc_total_size(struct zpool *pool) +{ + return zs_get_total_size_bytes(pool->zsmalloc_pool); +} + +static struct zpool_imp zpool_zsmalloc_imp = { + .destroy = zpool_zsmalloc_destroy, + .malloc = zpool_zsmalloc_malloc, + .free = zpool_zsmalloc_free, + .shrink = zpool_zsmalloc_shrink, + .map = zpool_zsmalloc_map, + .unmap = zpool_zsmalloc_unmap, + .total_size = zpool_zsmalloc_total_size +}; + +static struct zpool *zpool_zsmalloc_create(gfp_t flags, struct zpool_ops *ops) +{ + struct zpool *zpool; + + zpool = kmalloc(sizeof(*zpool), GFP_KERNEL); + if (!zpool) { + pr_err("couldn't create zpool - out of memory\n"); + return NULL; + } + + zpool->zsmalloc_pool = zs_create_pool(flags); + if (!zpool->zsmalloc_pool) { + kfree(zpool); + pr_err("zs_create_pool() failed\n"); + return NULL; + } + + zpool->type = ZPOOL_TYPE_ZSMALLOC; + zpool->imp = &zpool_zsmalloc_imp; + zpool->ops = &zpool_noop_ops; + spin_lock(&zpools_lock); + list_add(&zpool->list, &zpools); + spin_unlock(&zpools_lock); + + return zpool; +} + +#else + +static struct zpool *zpool_zsmalloc_create(gfp_t flags, struct zpool_ops *ops) +{ + pr_info("no zsmalloc in this kernel\n"); + return NULL; +} + +#endif /* CONFIG_ZSMALLOC */ + + +/* zbud */ + +#ifdef CONFIG_ZBUD + +static void zpool_zbud_destroy(struct zpool *zpool) +{ + spin_lock(&zpools_lock); + list_del(&zpool->list); + spin_unlock(&zpools_lock); + + zbud_destroy_pool(zpool->zbud_pool); + kfree(zpool); +} + +static int zpool_zbud_malloc(struct zpool *pool, size_t size, + unsigned long *handle) +{ + return zbud_alloc(pool->zbud_pool, size, handle); +} + +static void zpool_zbud_free(struct zpool *pool, unsigned long handle) +{ + zbud_free(pool->zbud_pool, handle); +} + +static int zpool_zbud_shrink(struct zpool *pool, size_t size) +{ + return zbud_reclaim_page(pool->zbud_pool, 3); +} + +static void *zpool_zbud_map(struct zpool *pool, unsigned long handle, + enum zpool_mapmode zpool_mapmode) +{ + return zbud_map(pool->zbud_pool, handle); +} + +static void zpool_zbud_unmap(struct zpool *pool, unsigned long handle) +{ + zbud_unmap(pool->zbud_pool, handle); +} + +static u64 zpool_zbud_total_size(struct zpool *pool) +{ + return zbud_get_pool_size(pool->zbud_pool) * PAGE_SIZE; +} + +static int zpool_zbud_evict(struct zbud_pool *zbud_pool, unsigned long handle) +{ + struct zpool *zpool; + + spin_lock(&zpools_lock); + list_for_each_entry(zpool, &zpools, list) { + if (zpool->zbud_pool == zbud_pool) { + spin_unlock(&zpools_lock); + return zpool->ops->evict(zpool, handle); + } + } + spin_unlock(&zpools_lock); + return -EINVAL; +} + +static struct zpool_imp zpool_zbud_imp = { + .destroy = zpool_zbud_destroy, + .malloc = zpool_zbud_malloc, + .free = zpool_zbud_free, + .shrink = zpool_zbud_shrink, + .map = zpool_zbud_map, + .unmap = zpool_zbud_unmap, + .total_size = zpool_zbud_total_size +}; + +static struct zbud_ops zpool_zbud_ops = { + .evict = zpool_zbud_evict +}; + +static struct zpool *zpool_zbud_create(gfp_t flags, struct zpool_ops *ops) +{ + struct zpool *zpool; + struct zbud_ops *zbud_ops = (ops ? &zpool_zbud_ops : NULL); + + zpool = kmalloc(sizeof(*zpool), GFP_KERNEL); + if (!zpool) { + pr_err("couldn't create zpool - out of memory\n"); + return NULL; + } + + zpool->zbud_pool = zbud_create_pool(flags, zbud_ops); + if (!zpool->zbud_pool) { + kfree(zpool); + pr_err("zbud_create_pool() failed\n"); + return NULL; + } + + zpool->type = ZPOOL_TYPE_ZBUD; + zpool->imp = &zpool_zbud_imp; + zpool->ops = (ops ? ops : &zpool_noop_ops); + spin_lock(&zpools_lock); + list_add(&zpool->list, &zpools); + spin_unlock(&zpools_lock); + + return zpool; +} + +#else + +static struct zpool *zpool_zbud_create(gfp_t flags, struct zpool_ops *ops) +{ + pr_info("no zbud in this kernel\n"); + return NULL; +} + +#endif /* CONFIG_ZBUD */ + + +struct zpool *zpool_create_pool(char *type, gfp_t flags, + struct zpool_ops *ops) +{ + struct zpool *pool = NULL; + + pr_info("creating pool type %s\n", type); + + if (!strcmp(type, ZPOOL_TYPE_ZSMALLOC)) + pool = zpool_zsmalloc_create(flags, ops); + else if (!strcmp(type, ZPOOL_TYPE_ZBUD)) + pool = zpool_zbud_create(flags, ops); + else + pr_err("unknown type %s\n", type); + + if (pool) + pr_info("created %s pool\n", type); + else + pr_err("couldn't create %s pool\n", type); + + return pool; +} + +char *zpool_get_type(struct zpool *pool) +{ + return pool->type; +} + +void zpool_destroy_pool(struct zpool *pool) +{ + pool->imp->destroy(pool); +} + +int zpool_malloc(struct zpool *pool, size_t size, unsigned long *handle) +{ + return pool->imp->malloc(pool, size, handle); +} + +void zpool_free(struct zpool *pool, unsigned long handle) +{ + pool->imp->free(pool, handle); +} + +int zpool_shrink(struct zpool *pool, size_t size) +{ + return pool->imp->shrink(pool, size); +} + +void *zpool_map_handle(struct zpool *pool, unsigned long handle, + enum zpool_mapmode mapmode) +{ + return pool->imp->map(pool, handle, mapmode); +} + +void zpool_unmap_handle(struct zpool *pool, unsigned long handle) +{ + pool->imp->unmap(pool, handle); +} + +u64 zpool_get_total_size(struct zpool *pool) +{ + return pool->imp->total_size(pool); +} -- 1.8.3.1 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
