1 files changed, 29 insertions, 20 deletions

diff --git a/drivers/md/dm-kcopyd.c b/drivers/md/dm-kcopyd.c
index 505b6f5cd385..24fb42ed7b8e 100644
--- a/drivers/md/dm-kcopyd.c
+++ b/drivers/md/dm-kcopyd.c
@@ -27,6 +27,10 @@
 
 #include "dm.h"
 
+#define SUB_JOB_SIZE    128
+#define SPLIT_COUNT     8
+#define MIN_JOBS        8
+
 /*-----------------------------------------------------------------
  * Each kcopyd client has its own little pool of preallocated
  * pages for kcopyd io.
@@ -216,16 +220,17 @@ struct kcopyd_job {
         struct mutex lock;
         atomic_t sub_jobs;
         sector_t progress;
-};
 
-/* FIXME: this should scale with the number of pages */
-#define MIN_JOBS 512
+        struct kcopyd_job *master_job;
+};
 
 static struct kmem_cache *_job_cache;
 
 int __init dm_kcopyd_init(void)
 {
-        _job_cache = KMEM_CACHE(kcopyd_job, 0);
+        _job_cache = kmem_cache_create("kcopyd_job",
+                                sizeof(struct kcopyd_job) * (SPLIT_COUNT + 1),
+                                __alignof__(struct kcopyd_job), 0, NULL);
         if (!_job_cache)
                 return -ENOMEM;
 
@@ -299,7 +304,12 @@ static int run_complete_job(struct kcopyd_job *job)
 
         if (job->pages)
                 kcopyd_put_pages(kc, job->pages);
-        mempool_free(job, kc->job_pool);
+        /*
+         * If this is the master job, the sub jobs have already
+         * completed so we can free everything.
+         */
+        if (job->master_job == job)
+                mempool_free(job, kc->job_pool);
         fn(read_err, write_err, context);
 
         if (atomic_dec_and_test(&kc->nr_jobs))
@@ -460,14 +470,14 @@ static void dispatch_job(struct kcopyd_job *job)
         wake(kc);
 }
 
-#define SUB_JOB_SIZE 128
 static void segment_complete(int read_err, unsigned long write_err,
                              void *context)
 {
         /* FIXME: tidy this function */
         sector_t progress = 0;
         sector_t count = 0;
-        struct kcopyd_job *job = (struct kcopyd_job *) context;
+        struct kcopyd_job *sub_job = (struct kcopyd_job *) context;
+        struct kcopyd_job *job = sub_job->master_job;
         struct dm_kcopyd_client *kc = job->kc;
 
         mutex_lock(&job->lock);
@@ -498,8 +508,6 @@ static void segment_complete(int read_err, unsigned long write_err,
 
         if (count) {
                 int i;
-                struct kcopyd_job *sub_job = mempool_alloc(kc->job_pool,
-                                                           GFP_NOIO);
 
                 *sub_job = *job;
                 sub_job->source.sector += progress;
@@ -511,7 +519,7 @@ static void segment_complete(int read_err, unsigned long write_err,
                 }
 
                 sub_job->fn = segment_complete;
-                sub_job->context = job;
+                sub_job->context = sub_job;
                 dispatch_job(sub_job);
 
         } else if (atomic_dec_and_test(&job->sub_jobs)) {
@@ -531,19 +539,19 @@ static void segment_complete(int read_err, unsigned long write_err,
 }
 
 /*
- * Create some little jobs that will do the move between
- * them.
+ * Create some sub jobs to share the work between them.
  */
-#define SPLIT_COUNT 8
-static void split_job(struct kcopyd_job *job)
+static void split_job(struct kcopyd_job *master_job)
 {
         int i;
 
-        atomic_inc(&job->kc->nr_jobs);
+        atomic_inc(&master_job->kc->nr_jobs);
 
-        atomic_set(&job->sub_jobs, SPLIT_COUNT);
-        for (i = 0; i < SPLIT_COUNT; i++)
-                segment_complete(0, 0u, job);
+        atomic_set(&master_job->sub_jobs, SPLIT_COUNT);
+        for (i = 0; i < SPLIT_COUNT; i++) {
+                master_job[i + 1].master_job = master_job;
+                segment_complete(0, 0u, &master_job[i + 1]);
+        }
 }
 
 int dm_kcopyd_copy(struct dm_kcopyd_client *kc, struct dm_io_region *from,
@@ -553,7 +561,8 @@ int dm_kcopyd_copy(struct dm_kcopyd_client *kc, struct dm_io_region *from,
         struct kcopyd_job *job;
 
         /*
-         * Allocate a new job.
+         * Allocate an array of jobs consisting of one master job
+         * followed by SPLIT_COUNT sub jobs.
          */
         job = mempool_alloc(kc->job_pool, GFP_NOIO);
 
@@ -577,10 +586,10 @@ int dm_kcopyd_copy(struct dm_kcopyd_client *kc, struct dm_io_region *from,
 
         job->fn = fn;
         job->context = context;
+        job->master_job = job;
 
         if (job->source.count <= SUB_JOB_SIZE)
                 dispatch_job(job);
-
         else {
                 mutex_init(&job->lock);
                 job->progress = 0;