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author | Ilya Dryomov <idryomov@gmail.com> | 2017-01-31 15:55:06 +0100 |
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committer | Ilya Dryomov <idryomov@gmail.com> | 2017-02-20 12:16:11 +0100 |
commit | 66a0e2d579dbec5c676cfe446234ffebb267c564 (patch) | |
tree | 6a2d4307be3e39e4955697a49ed5daf6ea97d927 /net/ceph/crush/mapper.c | |
parent | 1b6a78b5b91cdc07cc0b940b458e90c86835cf73 (diff) | |
download | linux-66a0e2d579dbec5c676cfe446234ffebb267c564.tar.bz2 |
crush: remove mutable part of CRUSH map
Then add it to the working state. It would be very nice if we didn't
have to take a lock to calculate a crush placement. By moving the
permutation array into the working data, we can treat the CRUSH map as
immutable.
Reflects ceph.git commit cbcd039651c0569551cb90d26ce27e1432671f2a.
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
Diffstat (limited to 'net/ceph/crush/mapper.c')
-rw-r--r-- | net/ceph/crush/mapper.c | 206 |
1 files changed, 138 insertions, 68 deletions
diff --git a/net/ceph/crush/mapper.c b/net/ceph/crush/mapper.c index 130ab407c5ec..9e75be5ec716 100644 --- a/net/ceph/crush/mapper.c +++ b/net/ceph/crush/mapper.c @@ -54,7 +54,6 @@ int crush_find_rule(const struct crush_map *map, int ruleset, int type, int size return -1; } - /* * bucket choose methods * @@ -72,59 +71,60 @@ int crush_find_rule(const struct crush_map *map, int ruleset, int type, int size * Since this is expensive, we optimize for the r=0 case, which * captures the vast majority of calls. */ -static int bucket_perm_choose(struct crush_bucket *bucket, +static int bucket_perm_choose(const struct crush_bucket *bucket, + struct crush_work_bucket *work, int x, int r) { unsigned int pr = r % bucket->size; unsigned int i, s; /* start a new permutation if @x has changed */ - if (bucket->perm_x != (__u32)x || bucket->perm_n == 0) { + if (work->perm_x != (__u32)x || work->perm_n == 0) { dprintk("bucket %d new x=%d\n", bucket->id, x); - bucket->perm_x = x; + work->perm_x = x; /* optimize common r=0 case */ if (pr == 0) { s = crush_hash32_3(bucket->hash, x, bucket->id, 0) % bucket->size; - bucket->perm[0] = s; - bucket->perm_n = 0xffff; /* magic value, see below */ + work->perm[0] = s; + work->perm_n = 0xffff; /* magic value, see below */ goto out; } for (i = 0; i < bucket->size; i++) - bucket->perm[i] = i; - bucket->perm_n = 0; - } else if (bucket->perm_n == 0xffff) { + work->perm[i] = i; + work->perm_n = 0; + } else if (work->perm_n == 0xffff) { /* clean up after the r=0 case above */ for (i = 1; i < bucket->size; i++) - bucket->perm[i] = i; - bucket->perm[bucket->perm[0]] = 0; - bucket->perm_n = 1; + work->perm[i] = i; + work->perm[work->perm[0]] = 0; + work->perm_n = 1; } /* calculate permutation up to pr */ - for (i = 0; i < bucket->perm_n; i++) + for (i = 0; i < work->perm_n; i++) dprintk(" perm_choose have %d: %d\n", i, bucket->perm[i]); - while (bucket->perm_n <= pr) { - unsigned int p = bucket->perm_n; + while (work->perm_n <= pr) { + unsigned int p = work->perm_n; /* no point in swapping the final entry */ if (p < bucket->size - 1) { i = crush_hash32_3(bucket->hash, x, bucket->id, p) % (bucket->size - p); if (i) { - unsigned int t = bucket->perm[p + i]; - bucket->perm[p + i] = bucket->perm[p]; - bucket->perm[p] = t; + unsigned int t = work->perm[p + i]; + work->perm[p + i] = work->perm[p]; + work->perm[p] = t; } dprintk(" perm_choose swap %d with %d\n", p, p+i); } - bucket->perm_n++; + work->perm_n++; } for (i = 0; i < bucket->size; i++) dprintk(" perm_choose %d: %d\n", i, bucket->perm[i]); - s = bucket->perm[pr]; + s = work->perm[pr]; out: dprintk(" perm_choose %d sz=%d x=%d r=%d (%d) s=%d\n", bucket->id, bucket->size, x, r, pr, s); @@ -132,14 +132,14 @@ out: } /* uniform */ -static int bucket_uniform_choose(struct crush_bucket_uniform *bucket, - int x, int r) +static int bucket_uniform_choose(const struct crush_bucket_uniform *bucket, + struct crush_work_bucket *work, int x, int r) { - return bucket_perm_choose(&bucket->h, x, r); + return bucket_perm_choose(&bucket->h, work, x, r); } /* list */ -static int bucket_list_choose(struct crush_bucket_list *bucket, +static int bucket_list_choose(const struct crush_bucket_list *bucket, int x, int r) { int i; @@ -155,8 +155,9 @@ static int bucket_list_choose(struct crush_bucket_list *bucket, w *= bucket->sum_weights[i]; w = w >> 16; /*dprintk(" scaled %llx\n", w);*/ - if (w < bucket->item_weights[i]) + if (w < bucket->item_weights[i]) { return bucket->h.items[i]; + } } dprintk("bad list sums for bucket %d\n", bucket->h.id); @@ -192,7 +193,7 @@ static int terminal(int x) return x & 1; } -static int bucket_tree_choose(struct crush_bucket_tree *bucket, +static int bucket_tree_choose(const struct crush_bucket_tree *bucket, int x, int r) { int n; @@ -224,7 +225,7 @@ static int bucket_tree_choose(struct crush_bucket_tree *bucket, /* straw */ -static int bucket_straw_choose(struct crush_bucket_straw *bucket, +static int bucket_straw_choose(const struct crush_bucket_straw *bucket, int x, int r) { __u32 i; @@ -301,7 +302,7 @@ static __u64 crush_ln(unsigned int xin) * */ -static int bucket_straw2_choose(struct crush_bucket_straw2 *bucket, +static int bucket_straw2_choose(const struct crush_bucket_straw2 *bucket, int x, int r) { unsigned int i, high = 0; @@ -344,37 +345,42 @@ static int bucket_straw2_choose(struct crush_bucket_straw2 *bucket, high_draw = draw; } } + return bucket->h.items[high]; } -static int crush_bucket_choose(struct crush_bucket *in, int x, int r) +static int crush_bucket_choose(const struct crush_bucket *in, + struct crush_work_bucket *work, + int x, int r) { dprintk(" crush_bucket_choose %d x=%d r=%d\n", in->id, x, r); BUG_ON(in->size == 0); switch (in->alg) { case CRUSH_BUCKET_UNIFORM: - return bucket_uniform_choose((struct crush_bucket_uniform *)in, - x, r); + return bucket_uniform_choose( + (const struct crush_bucket_uniform *)in, + work, x, r); case CRUSH_BUCKET_LIST: - return bucket_list_choose((struct crush_bucket_list *)in, + return bucket_list_choose((const struct crush_bucket_list *)in, x, r); case CRUSH_BUCKET_TREE: - return bucket_tree_choose((struct crush_bucket_tree *)in, + return bucket_tree_choose((const struct crush_bucket_tree *)in, x, r); case CRUSH_BUCKET_STRAW: - return bucket_straw_choose((struct crush_bucket_straw *)in, - x, r); + return bucket_straw_choose( + (const struct crush_bucket_straw *)in, + x, r); case CRUSH_BUCKET_STRAW2: - return bucket_straw2_choose((struct crush_bucket_straw2 *)in, - x, r); + return bucket_straw2_choose( + (const struct crush_bucket_straw2 *)in, + x, r); default: dprintk("unknown bucket %d alg %d\n", in->id, in->alg); return in->items[0]; } } - /* * true if device is marked "out" (failed, fully offloaded) * of the cluster @@ -416,7 +422,8 @@ static int is_out(const struct crush_map *map, * @parent_r: r value passed from the parent */ static int crush_choose_firstn(const struct crush_map *map, - struct crush_bucket *bucket, + struct crush_work *work, + const struct crush_bucket *bucket, const __u32 *weight, int weight_max, int x, int numrep, int type, int *out, int outpos, @@ -434,7 +441,7 @@ static int crush_choose_firstn(const struct crush_map *map, int rep; unsigned int ftotal, flocal; int retry_descent, retry_bucket, skip_rep; - struct crush_bucket *in = bucket; + const struct crush_bucket *in = bucket; int r; int i; int item = 0; @@ -473,9 +480,13 @@ static int crush_choose_firstn(const struct crush_map *map, if (local_fallback_retries > 0 && flocal >= (in->size>>1) && flocal > local_fallback_retries) - item = bucket_perm_choose(in, x, r); + item = bucket_perm_choose( + in, work->work[-1-in->id], + x, r); else - item = crush_bucket_choose(in, x, r); + item = crush_bucket_choose( + in, work->work[-1-in->id], + x, r); if (item >= map->max_devices) { dprintk(" bad item %d\n", item); skip_rep = 1; @@ -518,19 +529,21 @@ static int crush_choose_firstn(const struct crush_map *map, sub_r = r >> (vary_r-1); else sub_r = 0; - if (crush_choose_firstn(map, - map->buckets[-1-item], - weight, weight_max, - x, stable ? 1 : outpos+1, 0, - out2, outpos, count, - recurse_tries, 0, - local_retries, - local_fallback_retries, - 0, - vary_r, - stable, - NULL, - sub_r) <= outpos) + if (crush_choose_firstn( + map, + work, + map->buckets[-1-item], + weight, weight_max, + x, stable ? 1 : outpos+1, 0, + out2, outpos, count, + recurse_tries, 0, + local_retries, + local_fallback_retries, + 0, + vary_r, + stable, + NULL, + sub_r) <= outpos) /* didn't get leaf */ reject = 1; } else { @@ -600,7 +613,8 @@ reject: * */ static void crush_choose_indep(const struct crush_map *map, - struct crush_bucket *bucket, + struct crush_work *work, + const struct crush_bucket *bucket, const __u32 *weight, int weight_max, int x, int left, int numrep, int type, int *out, int outpos, @@ -610,7 +624,7 @@ static void crush_choose_indep(const struct crush_map *map, int *out2, int parent_r) { - struct crush_bucket *in = bucket; + const struct crush_bucket *in = bucket; int endpos = outpos + left; int rep; unsigned int ftotal; @@ -678,7 +692,9 @@ static void crush_choose_indep(const struct crush_map *map, break; } - item = crush_bucket_choose(in, x, r); + item = crush_bucket_choose( + in, work->work[-1-in->id], + x, r); if (item >= map->max_devices) { dprintk(" bad item %d\n", item); out[rep] = CRUSH_ITEM_NONE; @@ -724,13 +740,15 @@ static void crush_choose_indep(const struct crush_map *map, if (recurse_to_leaf) { if (item < 0) { - crush_choose_indep(map, - map->buckets[-1-item], - weight, weight_max, - x, 1, numrep, 0, - out2, rep, - recurse_tries, 0, - 0, NULL, r); + crush_choose_indep( + map, + work, + map->buckets[-1-item], + weight, weight_max, + x, 1, numrep, 0, + out2, rep, + recurse_tries, 0, + 0, NULL, r); if (out2[rep] == CRUSH_ITEM_NONE) { /* placed nothing; no leaf */ break; @@ -781,6 +799,53 @@ static void crush_choose_indep(const struct crush_map *map, #endif } + +/* + * This takes a chunk of memory and sets it up to be a shiny new + * working area for a CRUSH placement computation. It must be called + * on any newly allocated memory before passing it in to + * crush_do_rule. It may be used repeatedly after that, so long as the + * map has not changed. If the map /has/ changed, you must make sure + * the working size is no smaller than what was allocated and re-run + * crush_init_workspace. + * + * If you do retain the working space between calls to crush, make it + * thread-local. + */ +void crush_init_workspace(const struct crush_map *map, void *v) +{ + struct crush_work *w = v; + __s32 b; + + /* + * We work by moving through the available space and setting + * values and pointers as we go. + * + * It's a bit like Forth's use of the 'allot' word since we + * set the pointer first and then reserve the space for it to + * point to by incrementing the point. + */ + v += sizeof(struct crush_work *); + w->work = v; + v += map->max_buckets * sizeof(struct crush_work_bucket *); + for (b = 0; b < map->max_buckets; ++b) { + if (!map->buckets[b]) + continue; + + w->work[b] = v; + switch (map->buckets[b]->alg) { + default: + v += sizeof(struct crush_work_bucket); + break; + } + w->work[b]->perm_x = 0; + w->work[b]->perm_n = 0; + w->work[b]->perm = v; + v += map->buckets[b]->size * sizeof(__u32); + } + BUG_ON(v - (void *)w != map->working_size); +} + /** * crush_do_rule - calculate a mapping with the given input and rule * @map: the crush_map @@ -790,14 +855,16 @@ static void crush_choose_indep(const struct crush_map *map, * @result_max: maximum result size * @weight: weight vector (for map leaves) * @weight_max: size of weight vector + * @cwin: pointer to at least map->working_size bytes of memory * @scratch: scratch vector for private use; must be >= 3 * result_max */ int crush_do_rule(const struct crush_map *map, int ruleno, int x, int *result, int result_max, const __u32 *weight, int weight_max, - int *scratch) + void *cwin, int *scratch) { int result_len; + struct crush_work *cw = cwin; int *a = scratch; int *b = scratch + result_max; int *c = scratch + result_max*2; @@ -807,7 +874,7 @@ int crush_do_rule(const struct crush_map *map, int *o; int osize; int *tmp; - struct crush_rule *rule; + const struct crush_rule *rule; __u32 step; int i, j; int numrep; @@ -840,7 +907,7 @@ int crush_do_rule(const struct crush_map *map, for (step = 0; step < rule->len; step++) { int firstn = 0; - struct crush_rule_step *curstep = &rule->steps[step]; + const struct crush_rule_step *curstep = &rule->steps[step]; switch (curstep->op) { case CRUSH_RULE_TAKE: @@ -936,6 +1003,7 @@ int crush_do_rule(const struct crush_map *map, recurse_tries = choose_tries; osize += crush_choose_firstn( map, + cw, map->buckets[bno], weight, weight_max, x, numrep, @@ -956,6 +1024,7 @@ int crush_do_rule(const struct crush_map *map, numrep : (result_max-osize)); crush_choose_indep( map, + cw, map->buckets[bno], weight, weight_max, x, out_size, numrep, @@ -997,5 +1066,6 @@ int crush_do_rule(const struct crush_map *map, break; } } + return result_len; } |