dm: adjust structure members to improve alignment
authorMike Snitzer <snitzer@redhat.com>
Tue, 22 May 2018 22:26:20 +0000 (18:26 -0400)
committerMike Snitzer <snitzer@redhat.com>
Fri, 8 Jun 2018 15:53:14 +0000 (11:53 -0400)
Eliminate most holes in DM data structures that were modified by
commit 6f1c819c21 ("dm: convert to bioset_init()/mempool_init()").
Also prevent structure members from unnecessarily spanning cache
lines.

Signed-off-by: Mike Snitzer <snitzer@redhat.com>
drivers/md/dm-bio-prison-v1.c
drivers/md/dm-bio-prison-v2.c
drivers/md/dm-cache-target.c
drivers/md/dm-core.h
drivers/md/dm-crypt.c
drivers/md/dm-kcopyd.c
drivers/md/dm-region-hash.c
drivers/md/dm-thin.c
drivers/md/dm-zoned-target.c

index e794e36..b538989 100644 (file)
@@ -19,8 +19,8 @@
 
 struct dm_bio_prison {
        spinlock_t lock;
-       mempool_t cell_pool;
        struct rb_root cells;
+       mempool_t cell_pool;
 };
 
 static struct kmem_cache *_cell_cache;
index f866bc9..b092cdc 100644 (file)
@@ -21,8 +21,8 @@ struct dm_bio_prison_v2 {
        struct workqueue_struct *wq;
 
        spinlock_t lock;
-       mempool_t cell_pool;
        struct rb_root cells;
+       mempool_t cell_pool;
 };
 
 static struct kmem_cache *_cell_cache;
index 001c712..ce14a3d 100644 (file)
@@ -371,7 +371,13 @@ struct cache_stats {
 
 struct cache {
        struct dm_target *ti;
-       struct dm_target_callbacks callbacks;
+       spinlock_t lock;
+
+       /*
+        * Fields for converting from sectors to blocks.
+        */
+       int sectors_per_block_shift;
+       sector_t sectors_per_block;
 
        struct dm_cache_metadata *cmd;
 
@@ -402,13 +408,11 @@ struct cache {
        dm_cblock_t cache_size;
 
        /*
-        * Fields for converting from sectors to blocks.
+        * Invalidation fields.
         */
-       sector_t sectors_per_block;
-       int sectors_per_block_shift;
+       spinlock_t invalidation_lock;
+       struct list_head invalidation_requests;
 
-       spinlock_t lock;
-       struct bio_list deferred_bios;
        sector_t migration_threshold;
        wait_queue_head_t migration_wait;
        atomic_t nr_allocated_migrations;
@@ -419,13 +423,11 @@ struct cache {
         */
        atomic_t nr_io_migrations;
 
+       struct bio_list deferred_bios;
+
        struct rw_semaphore quiesce_lock;
 
-       /*
-        * cache_size entries, dirty if set
-        */
-       atomic_t nr_dirty;
-       unsigned long *dirty_bitset;
+       struct dm_target_callbacks callbacks;
 
        /*
         * origin_blocks entries, discarded if set.
@@ -442,17 +444,27 @@ struct cache {
        const char **ctr_args;
 
        struct dm_kcopyd_client *copier;
-       struct workqueue_struct *wq;
        struct work_struct deferred_bio_worker;
        struct work_struct migration_worker;
+       struct workqueue_struct *wq;
        struct delayed_work waker;
        struct dm_bio_prison_v2 *prison;
-       struct bio_set bs;
 
-       mempool_t migration_pool;
+       /*
+        * cache_size entries, dirty if set
+        */
+       unsigned long *dirty_bitset;
+       atomic_t nr_dirty;
 
-       struct dm_cache_policy *policy;
        unsigned policy_nr_args;
+       struct dm_cache_policy *policy;
+
+       /*
+        * Cache features such as write-through.
+        */
+       struct cache_features features;
+
+       struct cache_stats stats;
 
        bool need_tick_bio:1;
        bool sized:1;
@@ -461,25 +473,16 @@ struct cache {
        bool loaded_mappings:1;
        bool loaded_discards:1;
 
-       /*
-        * Cache features such as write-through.
-        */
-       struct cache_features features;
-
-       struct cache_stats stats;
+       struct rw_semaphore background_work_lock;
 
-       /*
-        * Invalidation fields.
-        */
-       spinlock_t invalidation_lock;
-       struct list_head invalidation_requests;
+       struct batcher committer;
+       struct work_struct commit_ws;
 
        struct io_tracker tracker;
 
-       struct work_struct commit_ws;
-       struct batcher committer;
+       mempool_t migration_pool;
 
-       struct rw_semaphore background_work_lock;
+       struct bio_set bs;
 };
 
 struct per_bio_data {
index f21c5d2..7d480c9 100644 (file)
@@ -31,6 +31,9 @@ struct dm_kobject_holder {
 struct mapped_device {
        struct mutex suspend_lock;
 
+       struct mutex table_devices_lock;
+       struct list_head table_devices;
+
        /*
         * The current mapping (struct dm_table *).
         * Use dm_get_live_table{_fast} or take suspend_lock for
@@ -38,17 +41,14 @@ struct mapped_device {
         */
        void __rcu *map;
 
-       struct list_head table_devices;
-       struct mutex table_devices_lock;
-
        unsigned long flags;
 
-       struct request_queue *queue;
-       int numa_node_id;
-
-       enum dm_queue_mode type;
        /* Protect queue and type against concurrent access. */
        struct mutex type_lock;
+       enum dm_queue_mode type;
+
+       int numa_node_id;
+       struct request_queue *queue;
 
        atomic_t holders;
        atomic_t open_count;
@@ -56,21 +56,21 @@ struct mapped_device {
        struct dm_target *immutable_target;
        struct target_type *immutable_target_type;
 
+       char name[16];
        struct gendisk *disk;
        struct dax_device *dax_dev;
-       char name[16];
-
-       void *interface_ptr;
 
        /*
         * A list of ios that arrived while we were suspended.
         */
-       atomic_t pending[2];
-       wait_queue_head_t wait;
        struct work_struct work;
+       wait_queue_head_t wait;
+       atomic_t pending[2];
        spinlock_t deferred_lock;
        struct bio_list deferred;
 
+       void *interface_ptr;
+
        /*
         * Event handling.
         */
@@ -84,17 +84,17 @@ struct mapped_device {
        unsigned internal_suspend_count;
 
        /*
-        * Processing queue (flush)
-        */
-       struct workqueue_struct *wq;
-
-       /*
         * io objects are allocated from here.
         */
        struct bio_set io_bs;
        struct bio_set bs;
 
        /*
+        * Processing queue (flush)
+        */
+       struct workqueue_struct *wq;
+
+       /*
         * freeze/thaw support require holding onto a super block
         */
        struct super_block *frozen_sb;
@@ -102,11 +102,11 @@ struct mapped_device {
        /* forced geometry settings */
        struct hd_geometry geometry;
 
-       struct block_device *bdev;
-
        /* kobject and completion */
        struct dm_kobject_holder kobj_holder;
 
+       struct block_device *bdev;
+
        /* zero-length flush that will be cloned and submitted to targets */
        struct bio flush_bio;
 
index da02f4d..4939fbc 100644 (file)
@@ -139,25 +139,13 @@ struct crypt_config {
        struct dm_dev *dev;
        sector_t start;
 
-       /*
-        * pool for per bio private data, crypto requests,
-        * encryption requeusts/buffer pages and integrity tags
-        */
-       mempool_t req_pool;
-       mempool_t page_pool;
-       mempool_t tag_pool;
-       unsigned tag_pool_max_sectors;
-
        struct percpu_counter n_allocated_pages;
 
-       struct bio_set bs;
-       struct mutex bio_alloc_lock;
-
        struct workqueue_struct *io_queue;
        struct workqueue_struct *crypt_queue;
 
-       struct task_struct *write_thread;
        wait_queue_head_t write_thread_wait;
+       struct task_struct *write_thread;
        struct rb_root write_tree;
 
        char *cipher;
@@ -213,6 +201,18 @@ struct crypt_config {
        unsigned int integrity_iv_size;
        unsigned int on_disk_tag_size;
 
+       /*
+        * pool for per bio private data, crypto requests,
+        * encryption requeusts/buffer pages and integrity tags
+        */
+       unsigned tag_pool_max_sectors;
+       mempool_t tag_pool;
+       mempool_t req_pool;
+       mempool_t page_pool;
+
+       struct bio_set bs;
+       struct mutex bio_alloc_lock;
+
        u8 *authenc_key; /* space for keys in authenc() format (if used) */
        u8 key[0];
 };
index ce7efc7..3c7547a 100644 (file)
@@ -45,7 +45,6 @@ struct dm_kcopyd_client {
        struct dm_io_client *io_client;
 
        wait_queue_head_t destroyq;
-       atomic_t nr_jobs;
 
        mempool_t job_pool;
 
@@ -54,6 +53,8 @@ struct dm_kcopyd_client {
 
        struct dm_kcopyd_throttle *throttle;
 
+       atomic_t nr_jobs;
+
 /*
  * We maintain three lists of jobs:
  *
index abf3521..c832ec3 100644 (file)
@@ -63,27 +63,28 @@ struct dm_region_hash {
 
        /* hash table */
        rwlock_t hash_lock;
-       mempool_t region_pool;
        unsigned mask;
        unsigned nr_buckets;
        unsigned prime;
        unsigned shift;
        struct list_head *buckets;
 
+       /*
+        * If there was a flush failure no regions can be marked clean.
+        */
+       int flush_failure;
+
        unsigned max_recovery; /* Max # of regions to recover in parallel */
 
        spinlock_t region_lock;
        atomic_t recovery_in_flight;
-       struct semaphore recovery_count;
        struct list_head clean_regions;
        struct list_head quiesced_regions;
        struct list_head recovered_regions;
        struct list_head failed_recovered_regions;
+       struct semaphore recovery_count;
 
-       /*
-        * If there was a flush failure no regions can be marked clean.
-        */
-       int flush_failure;
+       mempool_t region_pool;
 
        void *context;
        sector_t target_begin;
index 5772756..6cf9c93 100644 (file)
@@ -240,9 +240,9 @@ struct pool {
        struct dm_bio_prison *prison;
        struct dm_kcopyd_client *copier;
 
+       struct work_struct worker;
        struct workqueue_struct *wq;
        struct throttle throttle;
-       struct work_struct worker;
        struct delayed_work waker;
        struct delayed_work no_space_timeout;
 
@@ -260,7 +260,6 @@ struct pool {
        struct dm_deferred_set *all_io_ds;
 
        struct dm_thin_new_mapping *next_mapping;
-       mempool_t mapping_pool;
 
        process_bio_fn process_bio;
        process_bio_fn process_discard;
@@ -273,6 +272,8 @@ struct pool {
        process_mapping_fn process_prepared_discard_pt2;
 
        struct dm_bio_prison_cell **cell_sort_array;
+
+       mempool_t mapping_pool;
 };
 
 static enum pool_mode get_pool_mode(struct pool *pool);
index 30602d1..3c0e45f 100644 (file)
@@ -52,9 +52,9 @@ struct dmz_target {
        struct dmz_reclaim      *reclaim;
 
        /* For chunk work */
-       struct mutex            chunk_lock;
        struct radix_tree_root  chunk_rxtree;
        struct workqueue_struct *chunk_wq;
+       struct mutex            chunk_lock;
 
        /* For cloned BIOs to zones */
        struct bio_set          bio_set;