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 #else
  47
  48 struct blkio_group {
  49 };
  50
  51 #endif
  52
  53 #define BLKIO_WEIGHT_MIN        100
  54 #define BLKIO_WEIGHT_MAX        1000
  55 #define BLKIO_WEIGHT_DEFAULT    500
  56
  57 #ifdef CONFIG_DEBUG_BLK_CGROUP
  58 static inline char *blkg_path(struct blkio_group *blkg)
  59 {
  60         return blkg->path;
  61 }
  62 void blkiocg_update_blkio_group_dequeue_stats(struct blkio_group *blkg,
  63                                 unsigned long dequeue);
  64 #else
  65 static inline char *blkg_path(struct blkio_group *blkg) { return NULL; }
  66 static inline void blkiocg_update_blkio_group_dequeue_stats(
  67                         struct blkio_group *blkg, unsigned long dequeue) {}
  68 #endif
  69
  70 #ifdef CONFIG_BLK_CGROUP
  71 extern struct blkio_cgroup blkio_root_cgroup;
  72 extern struct blkio_cgroup *cgroup_to_blkio_cgroup(struct cgroup *cgroup);
  73 extern void blkiocg_add_blkio_group(struct blkio_cgroup *blkcg,
  74                         struct blkio_group *blkg, void *key, dev_t dev);
  75 extern int blkiocg_del_blkio_group(struct blkio_group *blkg);
  76 extern struct blkio_group *blkiocg_lookup_group(struct blkio_cgroup *blkcg,
  77                                                 void *key);
  78 void blkiocg_update_blkio_group_stats(struct blkio_group *blkg,
  79                         unsigned long time, unsigned long sectors);
  80 #else
  81 struct cgroup;
  82 static inline struct blkio_cgroup *
  83 cgroup_to_blkio_cgroup(struct cgroup *cgroup) { return NULL; }
  84
  85 static inline void blkiocg_add_blkio_group(struct blkio_cgroup *blkcg,
  86                         struct blkio_group *blkg, void *key, dev_t dev)
  87 {
  88 }
  89
  90 static inline int
  91 blkiocg_del_blkio_group(struct blkio_group *blkg) { return 0; }
  92
  93 static inline struct blkio_group *
  94 blkiocg_lookup_group(struct blkio_cgroup *blkcg, void *key) { return NULL; }
  95 static inline void blkiocg_update_blkio_group_stats(struct blkio_group *blkg,
  96                         unsigned long time, unsigned long sectors)
  97 {
  98 }
  99 #endif
 100 #endif /* _BLK_CGROUP_H */