drbd: add page pool to be used for meta data IO (4281808f) · Commits · e / devices / android_kernel_teracube_emerald

drivers/block/drbd/drbd_int.h

+22 −1

Original line number	Diff line number	Diff line
		@@ -1496,11 +1496,32 @@ extern struct kmem_cache drbd_al_ext_cache; / activity log extents */
		extern mempool_t *drbd_request_mempool;
		extern mempool_t *drbd_ee_mempool;

		extern struct page drbd_pp_pool; / drbd's page pool */
		/* drbd's page pool, used to buffer data received from the peer,
		* or data requested by the peer.
		*
		* This does not have an emergency reserve.
		*
		* When allocating from this pool, it first takes pages from the pool.
		* Only if the pool is depleted will try to allocate from the system.
		*
		* The assumption is that pages taken from this pool will be processed,
		* and given back, "quickly", and then can be recycled, so we can avoid
		* frequent calls to alloc_page(), and still will be able to make progress even
		* under memory pressure.
		*/
		extern struct page *drbd_pp_pool;
		extern spinlock_t drbd_pp_lock;
		extern int drbd_pp_vacant;
		extern wait_queue_head_t drbd_pp_wait;

		/* We also need a standard (emergency-reserve backed) page pool
		* for meta data IO (activity log, bitmap).
		* We can keep it global, as long as it is used as "N pages at a time".
		* 128 should be plenty, currently we probably can get away with as few as 1.
		*/
		#define DRBD_MIN_POOL_PAGES 128
		extern mempool_t *drbd_md_io_page_pool;

		extern rwlock_t global_state_lock;

		extern struct drbd_conf *drbd_new_device(unsigned int minor);

+9 −0

Original line number	Diff line number	Diff line
		@@ -139,6 +139,7 @@ struct kmem_cache drbd_bm_ext_cache; / bitmap extents */
		struct kmem_cache drbd_al_ext_cache; / activity log extents */
		mempool_t *drbd_request_mempool;
		mempool_t *drbd_ee_mempool;
		mempool_t *drbd_md_io_page_pool;

		/* I do not use a standard mempool, because:
		1) I want to hand out the pre-allocated objects first.
		@@ -3264,6 +3265,8 @@ static void drbd_destroy_mempools(void)

		/* D_ASSERT(atomic_read(&drbd_pp_vacant)==0); */

		if (drbd_md_io_page_pool)
		mempool_destroy(drbd_md_io_page_pool);
		if (drbd_ee_mempool)
		mempool_destroy(drbd_ee_mempool);
		if (drbd_request_mempool)
		@@ -3277,6 +3280,7 @@ static void drbd_destroy_mempools(void)
		if (drbd_al_ext_cache)
		kmem_cache_destroy(drbd_al_ext_cache);

		drbd_md_io_page_pool = NULL;
		drbd_ee_mempool = NULL;
		drbd_request_mempool = NULL;
		drbd_ee_cache = NULL;
		@@ -3300,6 +3304,7 @@ static int drbd_create_mempools(void)
		drbd_bm_ext_cache = NULL;
		drbd_al_ext_cache = NULL;
		drbd_pp_pool = NULL;
		drbd_md_io_page_pool = NULL;

		/* caches */
		drbd_request_cache = kmem_cache_create(
		@@ -3323,6 +3328,10 @@ static int drbd_create_mempools(void)
		goto Enomem;

		/* mempools */
		drbd_md_io_page_pool = mempool_create_page_pool(DRBD_MIN_POOL_PAGES, 0);
		if (drbd_md_io_page_pool == NULL)
		goto Enomem;

		drbd_request_mempool = mempool_create(number,
		mempool_alloc_slab, mempool_free_slab, drbd_request_cache);
		if (drbd_request_mempool == NULL)