67523c48aa
Modify the Block I/O cgroup subsystem to be able to be built as a module. As the CFQ disk scheduler optionally depends on blk-cgroup, config options in block/Kconfig, block/Kconfig.iosched, and block/blk-cgroup.h are enhanced to support the new module dependency. Signed-off-by: Ben Blum <bblum@andrew.cmu.edu> Cc: Li Zefan <lizf@cn.fujitsu.com> Cc: Paul Menage <menage@google.com> Cc: "David S. Miller" <davem@davemloft.net> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Lai Jiangshan <laijs@cn.fujitsu.com> Cc: Vivek Goyal <vgoyal@redhat.com> Cc: Jens Axboe <jens.axboe@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
93 lines
2 KiB
C
93 lines
2 KiB
C
#ifndef IOCONTEXT_H
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#define IOCONTEXT_H
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#include <linux/radix-tree.h>
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#include <linux/rcupdate.h>
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struct cfq_queue;
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struct cfq_io_context {
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void *key;
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unsigned long dead_key;
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struct cfq_queue *cfqq[2];
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struct io_context *ioc;
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unsigned long last_end_request;
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unsigned long ttime_total;
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unsigned long ttime_samples;
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unsigned long ttime_mean;
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struct list_head queue_list;
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struct hlist_node cic_list;
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void (*dtor)(struct io_context *); /* destructor */
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void (*exit)(struct io_context *); /* called on task exit */
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struct rcu_head rcu_head;
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};
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/*
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* I/O subsystem state of the associated processes. It is refcounted
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* and kmalloc'ed. These could be shared between processes.
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*/
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struct io_context {
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atomic_long_t refcount;
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atomic_t nr_tasks;
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/* all the fields below are protected by this lock */
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spinlock_t lock;
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unsigned short ioprio;
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unsigned short ioprio_changed;
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#if defined(CONFIG_BLK_CGROUP) || defined(CONFIG_BLK_CGROUP_MODULE)
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unsigned short cgroup_changed;
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#endif
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/*
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* For request batching
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*/
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int nr_batch_requests; /* Number of requests left in the batch */
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unsigned long last_waited; /* Time last woken after wait for request */
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struct radix_tree_root radix_root;
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struct hlist_head cic_list;
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void *ioc_data;
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};
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static inline struct io_context *ioc_task_link(struct io_context *ioc)
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{
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/*
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* if ref count is zero, don't allow sharing (ioc is going away, it's
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* a race).
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*/
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if (ioc && atomic_long_inc_not_zero(&ioc->refcount)) {
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atomic_inc(&ioc->nr_tasks);
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return ioc;
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}
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return NULL;
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}
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struct task_struct;
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#ifdef CONFIG_BLOCK
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int put_io_context(struct io_context *ioc);
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void exit_io_context(struct task_struct *task);
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struct io_context *get_io_context(gfp_t gfp_flags, int node);
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struct io_context *alloc_io_context(gfp_t gfp_flags, int node);
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void copy_io_context(struct io_context **pdst, struct io_context **psrc);
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#else
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static inline void exit_io_context(struct task_struct *task)
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{
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}
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struct io_context;
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static inline int put_io_context(struct io_context *ioc)
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{
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return 1;
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}
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#endif
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#endif
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