4 #include <linux/radix-tree.h>
5 #include <linux/rcupdate.h>
9 unsigned long last_end_request;
11 unsigned long ttime_total;
12 unsigned long ttime_samples;
13 unsigned long ttime_mean;
16 struct cfq_io_context {
18 struct request_queue *q;
20 struct cfq_queue *cfqq[2];
22 struct io_context *ioc;
24 struct cfq_ttime ttime;
26 struct list_head queue_list;
27 struct hlist_node cic_list;
29 void (*dtor)(struct io_context *); /* destructor */
30 void (*exit)(struct io_context *); /* called on task exit */
32 struct rcu_head rcu_head;
36 * I/O subsystem state of the associated processes. It is refcounted
37 * and kmalloc'ed. These could be shared between processes.
40 atomic_long_t refcount;
43 /* all the fields below are protected by this lock */
46 unsigned short ioprio;
47 unsigned short ioprio_changed;
49 #if defined(CONFIG_BLK_CGROUP) || defined(CONFIG_BLK_CGROUP_MODULE)
50 unsigned short cgroup_changed;
54 * For request batching
56 int nr_batch_requests; /* Number of requests left in the batch */
57 unsigned long last_waited; /* Time last woken after wait for request */
59 struct radix_tree_root radix_root;
60 struct hlist_head cic_list;
64 static inline struct io_context *ioc_task_link(struct io_context *ioc)
67 * if ref count is zero, don't allow sharing (ioc is going away, it's
70 if (ioc && atomic_long_inc_not_zero(&ioc->refcount)) {
71 atomic_inc(&ioc->nr_tasks);
80 void put_io_context(struct io_context *ioc);
81 void exit_io_context(struct task_struct *task);
82 struct io_context *get_task_io_context(struct task_struct *task,
83 gfp_t gfp_flags, int node);
86 static inline void put_io_context(struct io_context *ioc) { }
87 static inline void exit_io_context(struct task_struct *task) { }