58c24a6161
On 64 bit builds when CONFIG_BLK_CGROUP=n (the default) this removes 8 bytes of padding from structure io_context and drops its size from 72 to 64 bytes, so needing one fewer cachelines and allowing more objects per slab in it's kmem_cache. Signed-off-by: Richard Kennedy <richard@rsk.demon.co.uk> ---- patch against 2.6.33 compiled & test on x86_64 AMDX2 regards Richard Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
93 lines
2 KiB
C
93 lines
2 KiB
C
#ifndef IOCONTEXT_H
|
|
#define IOCONTEXT_H
|
|
|
|
#include <linux/radix-tree.h>
|
|
#include <linux/rcupdate.h>
|
|
|
|
struct cfq_queue;
|
|
struct cfq_io_context {
|
|
void *key;
|
|
unsigned long dead_key;
|
|
|
|
struct cfq_queue *cfqq[2];
|
|
|
|
struct io_context *ioc;
|
|
|
|
unsigned long last_end_request;
|
|
|
|
unsigned long ttime_total;
|
|
unsigned long ttime_samples;
|
|
unsigned long ttime_mean;
|
|
|
|
struct list_head queue_list;
|
|
struct hlist_node cic_list;
|
|
|
|
void (*dtor)(struct io_context *); /* destructor */
|
|
void (*exit)(struct io_context *); /* called on task exit */
|
|
|
|
struct rcu_head rcu_head;
|
|
};
|
|
|
|
/*
|
|
* I/O subsystem state of the associated processes. It is refcounted
|
|
* and kmalloc'ed. These could be shared between processes.
|
|
*/
|
|
struct io_context {
|
|
atomic_long_t refcount;
|
|
atomic_t nr_tasks;
|
|
|
|
/* all the fields below are protected by this lock */
|
|
spinlock_t lock;
|
|
|
|
unsigned short ioprio;
|
|
unsigned short ioprio_changed;
|
|
|
|
#ifdef CONFIG_BLK_CGROUP
|
|
unsigned short cgroup_changed;
|
|
#endif
|
|
|
|
/*
|
|
* For request batching
|
|
*/
|
|
int nr_batch_requests; /* Number of requests left in the batch */
|
|
unsigned long last_waited; /* Time last woken after wait for request */
|
|
|
|
struct radix_tree_root radix_root;
|
|
struct hlist_head cic_list;
|
|
void *ioc_data;
|
|
};
|
|
|
|
static inline struct io_context *ioc_task_link(struct io_context *ioc)
|
|
{
|
|
/*
|
|
* if ref count is zero, don't allow sharing (ioc is going away, it's
|
|
* a race).
|
|
*/
|
|
if (ioc && atomic_long_inc_not_zero(&ioc->refcount)) {
|
|
atomic_inc(&ioc->nr_tasks);
|
|
return ioc;
|
|
}
|
|
|
|
return NULL;
|
|
}
|
|
|
|
struct task_struct;
|
|
#ifdef CONFIG_BLOCK
|
|
int put_io_context(struct io_context *ioc);
|
|
void exit_io_context(struct task_struct *task);
|
|
struct io_context *get_io_context(gfp_t gfp_flags, int node);
|
|
struct io_context *alloc_io_context(gfp_t gfp_flags, int node);
|
|
void copy_io_context(struct io_context **pdst, struct io_context **psrc);
|
|
#else
|
|
static inline void exit_io_context(struct task_struct *task)
|
|
{
|
|
}
|
|
|
|
struct io_context;
|
|
static inline int put_io_context(struct io_context *ioc)
|
|
{
|
|
return 1;
|
|
}
|
|
#endif
|
|
|
|
#endif
|