diff options
Diffstat (limited to 'include/linux/crush/crush.h')
| -rw-r--r-- | include/linux/crush/crush.h | 66 |
1 files changed, 66 insertions, 0 deletions
diff --git a/include/linux/crush/crush.h b/include/linux/crush/crush.h index fbecbd089d75..92e165d417a6 100644 --- a/include/linux/crush/crush.h +++ b/include/linux/crush/crush.h @@ -2,6 +2,7 @@ #define CEPH_CRUSH_CRUSH_H #ifdef __KERNEL__ +# include <linux/rbtree.h> # include <linux/types.h> #else # include "crush_compat.h" @@ -137,6 +138,68 @@ struct crush_bucket { }; +/** @ingroup API + * + * Replacement weights for each item in a bucket. The size of the + * array must be exactly the size of the straw2 bucket, just as the + * item_weights array. + * + */ +struct crush_weight_set { + __u32 *weights; /*!< 16.16 fixed point weights + in the same order as items */ + __u32 size; /*!< size of the __weights__ array */ +}; + +/** @ingroup API + * + * Replacement weights and ids for a given straw2 bucket, for + * placement purposes. + * + * When crush_do_rule() chooses the Nth item from a straw2 bucket, the + * replacement weights found at __weight_set[N]__ are used instead of + * the weights from __item_weights__. If __N__ is greater than + * __weight_set_size__, the weights found at __weight_set_size-1__ are + * used instead. For instance if __weight_set__ is: + * + * [ [ 0x10000, 0x20000 ], // position 0 + * [ 0x20000, 0x40000 ] ] // position 1 + * + * choosing the 0th item will use position 0 weights [ 0x10000, 0x20000 ] + * choosing the 1th item will use position 1 weights [ 0x20000, 0x40000 ] + * choosing the 2th item will use position 1 weights [ 0x20000, 0x40000 ] + * etc. + * + */ +struct crush_choose_arg { + __s32 *ids; /*!< values to use instead of items */ + __u32 ids_size; /*!< size of the __ids__ array */ + struct crush_weight_set *weight_set; /*!< weight replacements for + a given position */ + __u32 weight_set_size; /*!< size of the __weight_set__ array */ +}; + +/** @ingroup API + * + * Replacement weights and ids for each bucket in the crushmap. The + * __size__ of the __args__ array must be exactly the same as the + * __map->max_buckets__. + * + * The __crush_choose_arg__ at index N will be used when choosing + * an item from the bucket __map->buckets[N]__ bucket, provided it + * is a straw2 bucket. + * + */ +struct crush_choose_arg_map { +#ifdef __KERNEL__ + struct rb_node node; + u64 choose_args_index; +#endif + struct crush_choose_arg *args; /*!< replacement for each bucket + in the crushmap */ + __u32 size; /*!< size of the __args__ array */ +}; + struct crush_bucket_uniform { struct crush_bucket h; __u32 item_weight; /* 16-bit fixed point; all items equally weighted */ @@ -236,6 +299,9 @@ struct crush_map { __u32 allowed_bucket_algs; __u32 *choose_tries; +#else + /* CrushWrapper::choose_args */ + struct rb_root choose_args; #endif }; |