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 struct blkio_cgroup {
  19         struct cgroup_subsys_state css;
  20         unsigned int weight;
  21         spinlock_t lock;
  22         struct hlist_head blkg_list;
  23 };
  24
  25 struct blkio_group {
  26         /* An rcu protected unique identifier for the group */
  27         void *key;
  28         struct hlist_node blkcg_node;
  29         unsigned short blkcg_id;
  30 #ifdef CONFIG_DEBUG_BLK_CGROUP
  31         /* Store cgroup path */
  32         char path[128];
  33         /* How many times this group has been removed from service tree */
  34         unsigned long dequeue;
  35 #endif
  36         /* The device MKDEV(major, minor), this group has been created for */
  37         dev_t   dev;
  38
  39         /* total disk time and nr sectors dispatched by this group */
  40         unsigned long time;
  41         unsigned long sectors;
  42 };
  43
  44 #define BLKIO_WEIGHT_MIN        100
  45 #define BLKIO_WEIGHT_MAX        1000
  46 #define BLKIO_WEIGHT_DEFAULT    500
  47
  48 #ifdef CONFIG_DEBUG_BLK_CGROUP
  49 static inline char *blkg_path(struct blkio_group *blkg)
  50 {
  51         return blkg->path;
  52 }
  53 void blkiocg_update_blkio_group_dequeue_stats(struct blkio_group *blkg,
  54                                 unsigned long dequeue);
  55 #else
  56 static inline char *blkg_path(struct blkio_group *blkg) { return NULL; }
  57 static inline void blkiocg_update_blkio_group_dequeue_stats(
  58                         struct blkio_group *blkg, unsigned long dequeue) {}
  59 #endif
  60
  61 #ifdef CONFIG_BLK_CGROUP
  62 extern struct blkio_cgroup blkio_root_cgroup;
  63 extern struct blkio_cgroup *cgroup_to_blkio_cgroup(struct cgroup *cgroup);
  64 extern void blkiocg_add_blkio_group(struct blkio_cgroup *blkcg,
  65                         struct blkio_group *blkg, void *key, dev_t dev);
  66 extern int blkiocg_del_blkio_group(struct blkio_group *blkg);
  67 extern struct blkio_group *blkiocg_lookup_group(struct blkio_cgroup *blkcg,
  68                                                 void *key);
  69 void blkiocg_update_blkio_group_stats(struct blkio_group *blkg,
  70                         unsigned long time, unsigned long sectors);
  71 #else
  72 static inline struct blkio_cgroup *
  73 cgroup_to_blkio_cgroup(struct cgroup *cgroup) { return NULL; }
  74
  75 static inline void blkiocg_add_blkio_group(struct blkio_cgroup *blkcg,
  76                         struct blkio_group *blkg, void *key, dev_t dev)
  77 {
  78 }
  79
  80 static inline int
  81 blkiocg_del_blkio_group(struct blkio_group *blkg) { return 0; }
  82
  83 static inline struct blkio_group *
  84 blkiocg_lookup_group(struct blkio_cgroup *blkcg, void *key) { return NULL; }
  85 static inline void blkiocg_update_blkio_group_stats(struct blkio_group *blkg,
  86                         unsigned long time, unsigned long sectors)
  87 {
  88 }
  89 #endif
  90 #endif /* _BLK_CGROUP_H */