Merge branch 'cfq-merge' of git://brick.kernel.dk/data/git/linux-2.6-block

* 'cfq-merge' of git://brick.kernel.dk/data/git/linux-2.6-block:
  [BLOCK] cfq-iosched: seek and async performance fixes
  [PATCH] ll_rw_blk: fix 80-col offender in put_io_context()
  [PATCH] cfq-iosched: small cfq_choose_req() optimization
  [PATCH] [BLOCK] cfq-iosched: change cfq io context linking from list to tree

block/ll_rw_blk.c

@@ -3539,11 +3539,17 @@ void put_io_context(struct io_context *ioc)
 	BUG_ON(atomic_read(&ioc->refcount) == 0);
 
 	if (atomic_dec_and_test(&ioc->refcount)) {
+		struct cfq_io_context *cic;
+
 		rcu_read_lock();
 		if (ioc->aic && ioc->aic->dtor)
 			ioc->aic->dtor(ioc->aic);
-		if (ioc->cic && ioc->cic->dtor)
-			ioc->cic->dtor(ioc->cic);
+		if (ioc->cic_root.rb_node != NULL) {
+			struct rb_node *n = rb_first(&ioc->cic_root);
+
+			cic = rb_entry(n, struct cfq_io_context, rb_node);
+			cic->dtor(ioc);
+		}
 		rcu_read_unlock();
 
 		kmem_cache_free(iocontext_cachep, ioc);
@@ -3556,6 +3562,7 @@ void exit_io_context(void)
 {
 	unsigned long flags;
 	struct io_context *ioc;
+	struct cfq_io_context *cic;
 
 	local_irq_save(flags);
 	task_lock(current);
@@ -3567,8 +3574,10 @@ void exit_io_context(void)
 
 	if (ioc->aic && ioc->aic->exit)
 		ioc->aic->exit(ioc->aic);
-	if (ioc->cic && ioc->cic->exit)
-		ioc->cic->exit(ioc->cic);
+	if (ioc->cic_root.rb_node != NULL) {
+		cic = rb_entry(rb_first(&ioc->cic_root), struct cfq_io_context, rb_node);
+		cic->exit(ioc);
+	}
  
 	put_io_context(ioc);
 }
@@ -3598,7 +3607,7 @@ struct io_context *current_io_context(gfp_t gfp_flags)
 		ret->last_waited = jiffies; /* doesn't matter... */
 		ret->nr_batch_requests = 0; /* because this is 0 */
 		ret->aic = NULL;
-		ret->cic = NULL;
+		ret->cic_root.rb_node = NULL;
 		tsk->io_context = ret;
 	}
 

include/linux/blkdev.h

@@ -55,25 +55,29 @@ struct as_io_context {
 
 struct cfq_queue;
 struct cfq_io_context {
-	/*
-	 * circular list of cfq_io_contexts belonging to a process io context
-	 */
-	struct list_head list;
-	struct cfq_queue *cfqq[2];
+	struct rb_node rb_node;
 	void *key;
 
+	struct cfq_queue *cfqq[2];
+
 	struct io_context *ioc;
 
 	unsigned long last_end_request;
+	sector_t last_request_pos;
  	unsigned long last_queue;
+
 	unsigned long ttime_total;
 	unsigned long ttime_samples;
 	unsigned long ttime_mean;
 
+	unsigned int seek_samples;
+	u64 seek_total;
+	sector_t seek_mean;
+
 	struct list_head queue_list;
 
-	void (*dtor)(struct cfq_io_context *);
-	void (*exit)(struct cfq_io_context *);
+	void (*dtor)(struct io_context *); /* destructor */
+	void (*exit)(struct io_context *); /* called on task exit */
 };
 
 /*
@@ -94,7 +98,7 @@ struct io_context {
 	int nr_batch_requests;     /* Number of requests left in the batch */
 
 	struct as_io_context *aic;
-	struct cfq_io_context *cic;
+	struct rb_root cic_root;
 };
 
 void put_io_context(struct io_context *ioc);