diff options
Diffstat (limited to 'mm/zpool.c')
| -rw-r--r-- | mm/zpool.c | 71 |
1 files changed, 46 insertions, 25 deletions
diff --git a/mm/zpool.c b/mm/zpool.c index fd3ff719c32c..f8cb83e7699b 100644 --- a/mm/zpool.c +++ b/mm/zpool.c @@ -21,6 +21,7 @@ struct zpool { struct zpool_driver *driver; void *pool; const struct zpool_ops *ops; + bool evictable; struct list_head list; }; @@ -100,7 +101,7 @@ static void zpool_put_driver(struct zpool_driver *driver) /** * zpool_has_pool() - Check if the pool driver is available - * @type The type of the zpool to check (e.g. zbud, zsmalloc) + * @type: The type of the zpool to check (e.g. zbud, zsmalloc) * * This checks if the @type pool driver is available. This will try to load * the requested module, if needed, but there is no guarantee the module will @@ -135,14 +136,14 @@ EXPORT_SYMBOL(zpool_has_pool); /** * zpool_create_pool() - Create a new zpool - * @type The type of the zpool to create (e.g. zbud, zsmalloc) - * @name The name of the zpool (e.g. zram0, zswap) - * @gfp The GFP flags to use when allocating the pool. - * @ops The optional ops callback. + * @type: The type of the zpool to create (e.g. zbud, zsmalloc) + * @name: The name of the zpool (e.g. zram0, zswap) + * @gfp: The GFP flags to use when allocating the pool. + * @ops: The optional ops callback. * * This creates a new zpool of the specified type. The gfp flags will be * used when allocating memory, if the implementation supports it. If the - * ops param is NULL, then the created zpool will not be shrinkable. + * ops param is NULL, then the created zpool will not be evictable. * * Implementations must guarantee this to be thread-safe. * @@ -180,6 +181,7 @@ struct zpool *zpool_create_pool(const char *type, const char *name, gfp_t gfp, zpool->driver = driver; zpool->pool = driver->create(name, gfp, ops, zpool); zpool->ops = ops; + zpool->evictable = driver->shrink && ops && ops->evict; if (!zpool->pool) { pr_err("couldn't create %s pool\n", type); @@ -199,7 +201,7 @@ struct zpool *zpool_create_pool(const char *type, const char *name, gfp_t gfp, /** * zpool_destroy_pool() - Destroy a zpool - * @pool The zpool to destroy. + * @zpool: The zpool to destroy. * * Implementations must guarantee this to be thread-safe, * however only when destroying different pools. The same @@ -222,7 +224,7 @@ void zpool_destroy_pool(struct zpool *zpool) /** * zpool_get_type() - Get the type of the zpool - * @pool The zpool to check + * @zpool: The zpool to check * * This returns the type of the pool. * @@ -237,10 +239,10 @@ const char *zpool_get_type(struct zpool *zpool) /** * zpool_malloc() - Allocate memory - * @pool The zpool to allocate from. - * @size The amount of memory to allocate. - * @gfp The GFP flags to use when allocating memory. - * @handle Pointer to the handle to set + * @zpool: The zpool to allocate from. + * @size: The amount of memory to allocate. + * @gfp: The GFP flags to use when allocating memory. + * @handle: Pointer to the handle to set * * This allocates the requested amount of memory from the pool. * The gfp flags will be used when allocating memory, if the @@ -259,8 +261,8 @@ int zpool_malloc(struct zpool *zpool, size_t size, gfp_t gfp, /** * zpool_free() - Free previously allocated memory - * @pool The zpool that allocated the memory. - * @handle The handle to the memory to free. + * @zpool: 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 @@ -278,9 +280,9 @@ void zpool_free(struct zpool *zpool, unsigned long handle) /** * zpool_shrink() - Shrink the pool size - * @pool The zpool to shrink. - * @pages The number of pages to shrink the pool. - * @reclaimed The number of pages successfully evicted. + * @zpool: The zpool to shrink. + * @pages: The number of pages to shrink the pool. + * @reclaimed: The number of pages successfully evicted. * * This attempts to shrink the actual memory size of the pool * by evicting currently used handle(s). If the pool was @@ -296,16 +298,17 @@ void zpool_free(struct zpool *zpool, unsigned long handle) int zpool_shrink(struct zpool *zpool, unsigned int pages, unsigned int *reclaimed) { - return zpool->driver->shrink(zpool->pool, pages, reclaimed); + return zpool->driver->shrink ? + zpool->driver->shrink(zpool->pool, pages, reclaimed) : -EINVAL; } /** * 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 + * @zpool: The zpool that the handle was allocated from + * @handle: The handle to map + * @mapmode: How the memory should be mapped * - * This maps a previously allocated handle into memory. The @mm + * This maps a previously allocated handle into memory. The @mapmode * param indicates to the implementation 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 @@ -329,8 +332,8 @@ void *zpool_map_handle(struct zpool *zpool, unsigned long handle, /** * zpool_unmap_handle() - Unmap a previously mapped handle - * @pool The zpool that the handle was allocated from - * @handle The handle to unmap + * @zpool: 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 implementation took in zpool_map_handle() @@ -344,7 +347,7 @@ void zpool_unmap_handle(struct zpool *zpool, unsigned long handle) /** * zpool_get_total_size() - The total size of the pool - * @pool The zpool to check + * @zpool: The zpool to check * * This returns the total size in bytes of the pool. * @@ -355,6 +358,24 @@ u64 zpool_get_total_size(struct zpool *zpool) return zpool->driver->total_size(zpool->pool); } +/** + * zpool_evictable() - Test if zpool is potentially evictable + * @pool The zpool to test + * + * Zpool is only potentially evictable when it's created with struct + * zpool_ops.evict and its driver implements struct zpool_driver.shrink. + * + * However, it doesn't necessarily mean driver will use zpool_ops.evict + * in its implementation of zpool_driver.shrink. It could do internal + * defragmentation instead. + * + * Returns: true if potentially evictable; false otherwise. + */ +bool zpool_evictable(struct zpool *zpool) +{ + return zpool->evictable; +} + MODULE_LICENSE("GPL"); MODULE_AUTHOR("Dan Streetman <ddstreet@ieee.org>"); MODULE_DESCRIPTION("Common API for compressed memory storage"); |