block/blk-cgroup.h

   1 #ifndef _BLK_CGROUP_H
   2 #define _BLK_CGROUP_H
   3 /*
   4  * Common Block IO controller cgroup interface
   5  *
   6  * Based on ideas and code from CFQ, CFS and BFQ:
   7  * Copyright (C) 2003 Jens Axboe <axboe@kernel.dk>
   8  *
   9  * Copyright (C) 2008 Fabio Checconi <fabio@gandalf.sssup.it>
  10  *                    Paolo Valente <paolo.valente@unimore.it>
  11  *
  12  * Copyright (C) 2009 Vivek Goyal <vgoyal@redhat.com>
  13  *                    Nauman Rafique <nauman@google.com>
  14  */
  15
  16 #include <linux/cgroup.h>
  17
  18 #ifdef CONFIG_BLK_CGROUP
  19
  20 struct blkio_cgroup {
  21         struct cgroup_subsys_state css;
  22         unsigned int weight;
  23         spinlock_t lock;
  24         struct hlist_head blkg_list;
  25 };
  26
  27 struct blkio_group {
  28         /* An rcu protected unique identifier for the group */
  29         void *key;
  30         struct hlist_node blkcg_node;
  31         unsigned short blkcg_id;
  32 #ifdef CONFIG_DEBUG_BLK_CGROUP
  33         /* Store cgroup path */
  34         char path[128];
  35         /* How many times this group has been removed from service tree */
  36         unsigned long dequeue;
  37 #endif
  38         /* The device MKDEV(major, minor), this group has been created for */
  39         dev_t   dev;
  40
  41         /* total disk time and nr sectors dispatched by this group */
  42         unsigned long time;
  43         unsigned long sectors;
  44 };
  45
  46 extern bool blkiocg_css_tryget(struct blkio_cgroup *blkcg);
  47 extern void blkiocg_css_put(struct blkio_cgroup *blkcg);
  48
  49 #else
  50
  51 struct blkio_group {
  52 };
  53
  54 #endif
  55
  56 #define BLKIO_WEIGHT_MIN        100
  57 #define BLKIO_WEIGHT_MAX        1000
  58 #define BLKIO_WEIGHT_DEFAULT    500
  59
  60 #ifdef CONFIG_DEBUG_BLK_CGROUP
  61 static inline char *blkg_path(struct blkio_group *blkg)
  62 {
  63         return blkg->path;
  64 }
  65 void blkiocg_update_blkio_group_dequeue_stats(struct blkio_group *blkg,
  66                                 unsigned long dequeue);
  67 #else
  68 static inline char *blkg_path(struct blkio_group *blkg) { return NULL; }
  69 static inline void blkiocg_update_blkio_group_dequeue_stats(
  70                         struct blkio_group *blkg, unsigned long dequeue) {}
  71 #endif
  72
  73 #ifdef CONFIG_BLK_CGROUP
  74 extern struct blkio_cgroup blkio_root_cgroup;
  75 extern struct blkio_cgroup *cgroup_to_blkio_cgroup(struct cgroup *cgroup);
  76 extern void blkiocg_add_blkio_group(struct blkio_cgroup *blkcg,
  77                         struct blkio_group *blkg, void *key, dev_t dev);
  78 extern int blkiocg_del_blkio_group(struct blkio_group *blkg);
  79 extern struct blkio_group *blkiocg_lookup_group(struct blkio_cgroup *blkcg,
  80                                                 void *key);
  81 void blkiocg_update_blkio_group_stats(struct blkio_group *blkg,
  82                         unsigned long time, unsigned long sectors);
  83 #else
  84 struct cgroup;
  85 static inline struct blkio_cgroup *
  86 cgroup_to_blkio_cgroup(struct cgroup *cgroup) { return NULL; }
  87
  88 static inline void blkiocg_add_blkio_group(struct blkio_cgroup *blkcg,
  89                         struct blkio_group *blkg, void *key, dev_t dev)
  90 {
  91 }
  92
  93 static inline int
  94 blkiocg_del_blkio_group(struct blkio_group *blkg) { return 0; }
  95
  96 static inline struct blkio_group *
  97 blkiocg_lookup_group(struct blkio_cgroup *blkcg, void *key) { return NULL; }
  98 static inline void blkiocg_update_blkio_group_stats(struct blkio_group *blkg,
  99                         unsigned long time, unsigned long sectors)
 100 {
 101 }
 102 #endif
 103 #endif /* _BLK_CGROUP_H */