};
+/** @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 {
+ 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 */
*
*/
+static __u32 *get_choose_arg_weights(const struct crush_bucket_straw2 *bucket,
+ const struct crush_choose_arg *arg,
+ int position)
+{
+ if (!arg || !arg->weight_set || arg->weight_set_size == 0)
+ return bucket->item_weights;
+
+ if (position >= arg->weight_set_size)
+ position = arg->weight_set_size - 1;
+ return arg->weight_set[position].weights;
+}
+
+static __s32 *get_choose_arg_ids(const struct crush_bucket_straw2 *bucket,
+ const struct crush_choose_arg *arg)
+{
+ if (!arg || !arg->ids)
+ return bucket->h.items;
+
+ return arg->ids;
+}
+
static int bucket_straw2_choose(const struct crush_bucket_straw2 *bucket,
- int x, int r)
+ int x, int r,
+ const struct crush_choose_arg *arg,
+ int position)
{
unsigned int i, high = 0;
unsigned int u;
- unsigned int w;
__s64 ln, draw, high_draw = 0;
+ __u32 *weights = get_choose_arg_weights(bucket, arg, position);
+ __s32 *ids = get_choose_arg_ids(bucket, arg);
for (i = 0; i < bucket->h.size; i++) {
- w = bucket->item_weights[i];
- if (w) {
- u = crush_hash32_3(bucket->h.hash, x,
- bucket->h.items[i], r);
+ dprintk("weight 0x%x item %d\n", weights[i], ids[i]);
+ if (weights[i]) {
+ u = crush_hash32_3(bucket->h.hash, x, ids[i], r);
u &= 0xffff;
/*
* weight means a larger (less negative) value
* for draw.
*/
- draw = div64_s64(ln, w);
+ draw = div64_s64(ln, weights[i]);
} else {
draw = S64_MIN;
}
static int crush_bucket_choose(const struct crush_bucket *in,
struct crush_work_bucket *work,
- int x, int r)
+ int x, int r,
+ const struct crush_choose_arg *arg,
+ int position)
{
dprintk(" crush_bucket_choose %d x=%d r=%d\n", in->id, x, r);
BUG_ON(in->size == 0);
case CRUSH_BUCKET_STRAW2:
return bucket_straw2_choose(
(const struct crush_bucket_straw2 *)in,
- x, r);
+ x, r, arg, position);
default:
dprintk("unknown bucket %d alg %d\n", in->id, in->alg);
return in->items[0];
unsigned int vary_r,
unsigned int stable,
int *out2,
- int parent_r)
+ int parent_r,
+ const struct crush_choose_arg *choose_args)
{
int rep;
unsigned int ftotal, flocal;
else
item = crush_bucket_choose(
in, work->work[-1-in->id],
- x, r);
+ x, r,
+ (choose_args ?
+ &choose_args[-1-in->id] : 0),
+ outpos);
if (item >= map->max_devices) {
dprintk(" bad item %d\n", item);
skip_rep = 1;
vary_r,
stable,
NULL,
- sub_r) <= outpos)
+ sub_r,
+ choose_args) <= outpos)
/* didn't get leaf */
reject = 1;
} else {
unsigned int recurse_tries,
int recurse_to_leaf,
int *out2,
- int parent_r)
+ int parent_r,
+ const struct crush_choose_arg *choose_args)
{
const struct crush_bucket *in = bucket;
int endpos = outpos + left;
item = crush_bucket_choose(
in, work->work[-1-in->id],
- x, r);
+ x, r,
+ (choose_args ?
+ &choose_args[-1-in->id] : 0),
+ outpos);
if (item >= map->max_devices) {
dprintk(" bad item %d\n", item);
out[rep] = CRUSH_ITEM_NONE;
x, 1, numrep, 0,
out2, rep,
recurse_tries, 0,
- 0, NULL, r);
+ 0, NULL, r,
+ choose_args);
if (out2[rep] == CRUSH_ITEM_NONE) {
/* placed nothing; no leaf */
break;
* @weight: weight vector (for map leaves)
* @weight_max: size of weight vector
* @cwin: pointer to at least crush_work_size() bytes of memory
+ * @choose_args: weights and ids for each known bucket
*/
int crush_do_rule(const struct crush_map *map,
int ruleno, int x, int *result, int result_max,
const __u32 *weight, int weight_max,
- void *cwin)
+ void *cwin, const struct crush_choose_arg *choose_args)
{
int result_len;
struct crush_work *cw = cwin;
vary_r,
stable,
c+osize,
- 0);
+ 0,
+ choose_args);
} else {
out_size = ((numrep < (result_max-osize)) ?
numrep : (result_max-osize));
choose_leaf_tries : 1,
recurse_to_leaf,
c+osize,
- 0);
+ 0,
+ choose_args);
osize += out_size;
}
}
projects / platform / kernel / linux-rpi.git / commitdiff