[SCSI] libsas: trim sas_task of slow path infrastructure

The timer and the completion are only used for slow path tasks (smp, and
lldd tmfs), yet we incur the allocation space and cpu setup time for
every fast path task.

Cc: Xiangliang Yu <yuxiangl@marvell.com>
Acked-by: Jack Wang <jack_wang@usish.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>

1 files changed, 21 insertions, 2 deletions

diff --git a/drivers/scsi/libsas/sas_init.c b/drivers/scsi/libsas/sas_init.c
index 1bbab3d94a20..014297c05880 100644
--- a/drivers/scsi/libsas/sas_init.c
+++ b/drivers/scsi/libsas/sas_init.c
@@ -48,18 +48,37 @@ struct sas_task *sas_alloc_task(gfp_t flags)
 		INIT_LIST_HEAD(&task->list);
 		spin_lock_init(&task->task_state_lock);
 		task->task_state_flags = SAS_TASK_STATE_PENDING;
-		init_timer(&task->timer);
-		init_completion(&task->completion);
 	}
 
 	return task;
 }
 EXPORT_SYMBOL_GPL(sas_alloc_task);
 
+struct sas_task *sas_alloc_slow_task(gfp_t flags)
+{
+	struct sas_task *task = sas_alloc_task(flags);
+	struct sas_task_slow *slow = kmalloc(sizeof(*slow), flags);
+
+	if (!task || !slow) {
+		if (task)
+			kmem_cache_free(sas_task_cache, task);
+		kfree(slow);
+		return NULL;
+	}
+
+	task->slow_task = slow;
+	init_timer(&slow->timer);
+	init_completion(&slow->completion);
+
+	return task;
+}
+EXPORT_SYMBOL_GPL(sas_alloc_slow_task);
+
 void sas_free_task(struct sas_task *task)
 {
 	if (task) {
 		BUG_ON(!list_empty(&task->list));
+		kfree(task->slow_task);
 		kmem_cache_free(sas_task_cache, task);
 	}
 }