From 9069a3817d82b01b3a55da382c774e3575946130 Mon Sep 17 00:00:00 2001 From: Jiri Pirko Date: Thu, 7 Feb 2019 11:22:46 +0000 Subject: lib: objagg: implement optimization hints assembly and use hints for object creation Implement simple greedy algo to find more optimized root-delta tree for a given objagg instance. This "hints" can be used by a driver to: 1) check if the hints are better (driver's choice) than the original objagg tree. Driver does comparison of objagg stats and hints stats. 2) use the hints to create a new objagg instance which will construct the root-delta tree according to the passed hints. Currently, only a simple greedy algorithm is implemented. Basically it finds the roots according to the maximal possible user count including deltas. Signed-off-by: Jiri Pirko Signed-off-by: Ido Schimmel Signed-off-by: David S. Miller --- lib/objagg.c | 573 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++-- 1 file changed, 560 insertions(+), 13 deletions(-) (limited to 'lib/objagg.c') diff --git a/lib/objagg.c b/lib/objagg.c index dae390bcef1a..befe8a47d080 100644 --- a/lib/objagg.c +++ b/lib/objagg.c @@ -4,6 +4,7 @@ #include #include #include +#include #include #include #include @@ -11,6 +12,34 @@ #define CREATE_TRACE_POINTS #include +struct objagg_hints { + struct rhashtable node_ht; + struct rhashtable_params ht_params; + struct list_head node_list; + unsigned int node_count; + unsigned int root_count; + unsigned int refcount; + const struct objagg_ops *ops; +}; + +struct objagg_hints_node { + struct rhash_head ht_node; /* member of objagg_hints->node_ht */ + struct list_head list; /* member of objagg_hints->node_list */ + struct objagg_hints_node *parent; + unsigned int root_id; + struct objagg_obj_stats_info stats_info; + unsigned long obj[0]; +}; + +static struct objagg_hints_node * +objagg_hints_lookup(struct objagg_hints *objagg_hints, void *obj) +{ + if (!objagg_hints) + return NULL; + return rhashtable_lookup_fast(&objagg_hints->node_ht, obj, + objagg_hints->ht_params); +} + struct objagg { const struct objagg_ops *ops; void *priv; @@ -18,6 +47,8 @@ struct objagg { struct rhashtable_params ht_params; struct list_head obj_list; unsigned int obj_count; + struct ida root_ida; + struct objagg_hints *hints; }; struct objagg_obj { @@ -30,6 +61,7 @@ struct objagg_obj { void *delta_priv; /* user delta private */ void *root_priv; /* user root private */ }; + unsigned int root_id; unsigned int refcount; /* counts number of users of this object * including nested objects */ @@ -130,7 +162,8 @@ static struct objagg_obj *objagg_obj_lookup(struct objagg *objagg, void *obj) static int objagg_obj_parent_assign(struct objagg *objagg, struct objagg_obj *objagg_obj, - struct objagg_obj *parent) + struct objagg_obj *parent, + bool take_parent_ref) { void *delta_priv; @@ -144,7 +177,8 @@ static int objagg_obj_parent_assign(struct objagg *objagg, */ objagg_obj->parent = parent; objagg_obj->delta_priv = delta_priv; - objagg_obj_ref_inc(objagg_obj->parent); + if (take_parent_ref) + objagg_obj_ref_inc(objagg_obj->parent); trace_objagg_obj_parent_assign(objagg, objagg_obj, parent, parent->refcount); @@ -164,7 +198,7 @@ static int objagg_obj_parent_lookup_assign(struct objagg *objagg, if (!objagg_obj_is_root(objagg_obj_cur)) continue; err = objagg_obj_parent_assign(objagg, objagg_obj, - objagg_obj_cur); + objagg_obj_cur, true); if (!err) return 0; } @@ -184,16 +218,68 @@ static void objagg_obj_parent_unassign(struct objagg *objagg, __objagg_obj_put(objagg, objagg_obj->parent); } +static int objagg_obj_root_id_alloc(struct objagg *objagg, + struct objagg_obj *objagg_obj, + struct objagg_hints_node *hnode) +{ + unsigned int min, max; + int root_id; + + /* In case there are no hints available, the root id is invalid. */ + if (!objagg->hints) { + objagg_obj->root_id = OBJAGG_OBJ_ROOT_ID_INVALID; + return 0; + } + + if (hnode) { + min = hnode->root_id; + max = hnode->root_id; + } else { + /* For objects with no hint, start after the last + * hinted root_id. + */ + min = objagg->hints->root_count; + max = ~0; + } + + root_id = ida_alloc_range(&objagg->root_ida, min, max, GFP_KERNEL); + + if (root_id < 0) + return root_id; + objagg_obj->root_id = root_id; + return 0; +} + +static void objagg_obj_root_id_free(struct objagg *objagg, + struct objagg_obj *objagg_obj) +{ + if (!objagg->hints) + return; + ida_free(&objagg->root_ida, objagg_obj->root_id); +} + static int objagg_obj_root_create(struct objagg *objagg, - struct objagg_obj *objagg_obj) + struct objagg_obj *objagg_obj, + struct objagg_hints_node *hnode) { - objagg_obj->root_priv = objagg->ops->root_create(objagg->priv, - objagg_obj->obj); - if (IS_ERR(objagg_obj->root_priv)) - return PTR_ERR(objagg_obj->root_priv); + int err; + err = objagg_obj_root_id_alloc(objagg, objagg_obj, hnode); + if (err) + return err; + objagg_obj->root_priv = objagg->ops->root_create(objagg->priv, + objagg_obj->obj, + objagg_obj->root_id); + if (IS_ERR(objagg_obj->root_priv)) { + err = PTR_ERR(objagg_obj->root_priv); + goto err_root_create; + } trace_objagg_obj_root_create(objagg, objagg_obj); return 0; + +err_root_create: + objagg_obj_root_id_free(objagg, objagg_obj); + return err; } static void objagg_obj_root_destroy(struct objagg *objagg, @@ -201,19 +287,69 @@ static void objagg_obj_root_destroy(struct objagg *objagg, { trace_objagg_obj_root_destroy(objagg, objagg_obj); objagg->ops->root_destroy(objagg->priv, objagg_obj->root_priv); + objagg_obj_root_id_free(objagg, objagg_obj); +} + +static struct objagg_obj *__objagg_obj_get(struct objagg *objagg, void *obj); + +static int objagg_obj_init_with_hints(struct objagg *objagg, + struct objagg_obj *objagg_obj, + bool *hint_found) +{ + struct objagg_hints_node *hnode; + struct objagg_obj *parent; + int err; + + hnode = objagg_hints_lookup(objagg->hints, objagg_obj->obj); + if (!hnode) { + *hint_found = false; + return 0; + } + *hint_found = true; + + if (!hnode->parent) + return objagg_obj_root_create(objagg, objagg_obj, hnode); + + parent = __objagg_obj_get(objagg, hnode->parent->obj); + if (IS_ERR(parent)) + return PTR_ERR(parent); + + err = objagg_obj_parent_assign(objagg, objagg_obj, parent, false); + if (err) { + *hint_found = false; + err = 0; + goto err_parent_assign; + } + + return 0; + +err_parent_assign: + objagg_obj_put(objagg, parent); + return err; } static int objagg_obj_init(struct objagg *objagg, struct objagg_obj *objagg_obj) { + bool hint_found; int err; + /* First, try to use hints if they are available and + * if they provide result. + */ + err = objagg_obj_init_with_hints(objagg, objagg_obj, &hint_found); + if (err) + return err; + + if (hint_found) + return 0; + /* Try to find if the object can be aggregated under an existing one. */ err = objagg_obj_parent_lookup_assign(objagg, objagg_obj); if (!err) return 0; /* If aggregation is not possible, make the object a root. */ - return objagg_obj_root_create(objagg, objagg_obj); + return objagg_obj_root_create(objagg, objagg_obj, NULL); } static void objagg_obj_fini(struct objagg *objagg, @@ -349,8 +485,9 @@ EXPORT_SYMBOL(objagg_obj_put); /** * objagg_create - creates a new objagg instance - * @ops: user-specific callbacks - * @priv: pointer to a private data passed to the ops + * @ops: user-specific callbacks + * @objagg_hints: hints, can be NULL + * @priv: pointer to a private data passed to the ops * * Note: all locking must be provided by the caller. * @@ -374,18 +511,25 @@ EXPORT_SYMBOL(objagg_obj_put); * Returns a pointer to newly created objagg instance in case of success, * otherwise it returns pointer error using ERR_PTR macro. */ -struct objagg *objagg_create(const struct objagg_ops *ops, void *priv) +struct objagg *objagg_create(const struct objagg_ops *ops, + struct objagg_hints *objagg_hints, void *priv) { struct objagg *objagg; int err; if (WARN_ON(!ops || !ops->root_create || !ops->root_destroy || - !ops->delta_create || !ops->delta_destroy)) + !ops->delta_check || !ops->delta_create || + !ops->delta_destroy)) return ERR_PTR(-EINVAL); + objagg = kzalloc(sizeof(*objagg), GFP_KERNEL); if (!objagg) return ERR_PTR(-ENOMEM); objagg->ops = ops; + if (objagg_hints) { + objagg->hints = objagg_hints; + objagg_hints->refcount++; + } objagg->priv = priv; INIT_LIST_HEAD(&objagg->obj_list); @@ -397,6 +541,8 @@ struct objagg *objagg_create(const struct objagg_ops *ops, void *priv) if (err) goto err_rhashtable_init; + ida_init(&objagg->root_ida); + trace_objagg_create(objagg); return objagg; @@ -415,8 +561,11 @@ EXPORT_SYMBOL(objagg_create); void objagg_destroy(struct objagg *objagg) { trace_objagg_destroy(objagg); + ida_destroy(&objagg->root_ida); WARN_ON(!list_empty(&objagg->obj_list)); rhashtable_destroy(&objagg->obj_ht); + if (objagg->hints) + objagg_hints_put(objagg->hints); kfree(objagg); } EXPORT_SYMBOL(objagg_destroy); @@ -496,6 +645,404 @@ void objagg_stats_put(const struct objagg_stats *objagg_stats) } EXPORT_SYMBOL(objagg_stats_put); +static struct objagg_hints_node * +objagg_hints_node_create(struct objagg_hints *objagg_hints, + struct objagg_obj *objagg_obj, size_t obj_size, + struct objagg_hints_node *parent_hnode) +{ + unsigned int user_count = objagg_obj->stats.user_count; + struct objagg_hints_node *hnode; + int err; + + hnode = kzalloc(sizeof(*hnode) + obj_size, GFP_KERNEL); + if (!hnode) + return ERR_PTR(-ENOMEM); + memcpy(hnode->obj, &objagg_obj->obj, obj_size); + hnode->stats_info.stats.user_count = user_count; + hnode->stats_info.stats.delta_user_count = user_count; + if (parent_hnode) { + parent_hnode->stats_info.stats.delta_user_count += user_count; + } else { + hnode->root_id = objagg_hints->root_count++; + hnode->stats_info.is_root = true; + } + hnode->stats_info.objagg_obj = objagg_obj; + + err = rhashtable_insert_fast(&objagg_hints->node_ht, &hnode->ht_node, + objagg_hints->ht_params); + if (err) + goto err_ht_insert; + + list_add(&hnode->list, &objagg_hints->node_list); + hnode->parent = parent_hnode; + objagg_hints->node_count++; + + return hnode; + +err_ht_insert: + kfree(hnode); + return ERR_PTR(err); +} + +static void objagg_hints_flush(struct objagg_hints *objagg_hints) +{ + struct objagg_hints_node *hnode, *tmp; + + list_for_each_entry_safe(hnode, tmp, &objagg_hints->node_list, list) { + list_del(&hnode->list); + rhashtable_remove_fast(&objagg_hints->node_ht, &hnode->ht_node, + objagg_hints->ht_params); + kfree(hnode); + } +} + +struct objagg_tmp_node { + struct objagg_obj *objagg_obj; + bool crossed_out; +}; + +struct objagg_tmp_graph { + struct objagg_tmp_node *nodes; + unsigned long nodes_count; + unsigned long *edges; +}; + +static int objagg_tmp_graph_edge_index(struct objagg_tmp_graph *graph, + int parent_index, int index) +{ + return index * graph->nodes_count + parent_index; +} + +static void objagg_tmp_graph_edge_set(struct objagg_tmp_graph *graph, + int parent_index, int index) +{ + int edge_index = objagg_tmp_graph_edge_index(graph, index, + parent_index); + + __set_bit(edge_index, graph->edges); +} + +static bool objagg_tmp_graph_is_edge(struct objagg_tmp_graph *graph, + int parent_index, int index) +{ + int edge_index = objagg_tmp_graph_edge_index(graph, index, + parent_index); + + return test_bit(edge_index, graph->edges); +} + +static unsigned int objagg_tmp_graph_node_weight(struct objagg_tmp_graph *graph, + unsigned int index) +{ + struct objagg_tmp_node *node = &graph->nodes[index]; + unsigned int weight = node->objagg_obj->stats.user_count; + int j; + + /* Node weight is sum of node users and all other nodes users + * that this node can represent with delta. + */ + + if (node->crossed_out) + return 0; + for (j = 0; j < graph->nodes_count; j++) { + if (!objagg_tmp_graph_is_edge(graph, index, j)) + continue; + node = &graph->nodes[j]; + if (node->crossed_out) + continue; + weight += node->objagg_obj->stats.user_count; + } + return weight; +} + +static int objagg_tmp_graph_node_max_weight(struct objagg_tmp_graph *graph) +{ + unsigned int max_weight = 0; + unsigned int weight; + int max_index = -1; + int i; + + for (i = 0; i < graph->nodes_count; i++) { + weight = objagg_tmp_graph_node_weight(graph, i); + if (weight > max_weight) { + max_weight = weight; + max_index = i; + } + } + return max_index; +} + +static struct objagg_tmp_graph *objagg_tmp_graph_create(struct objagg *objagg) +{ + unsigned int nodes_count = objagg->obj_count; + struct objagg_tmp_graph *graph; + struct objagg_tmp_node *node; + struct objagg_tmp_node *pnode; + struct objagg_obj *objagg_obj; + size_t alloc_size; + int i, j; + + graph = kzalloc(sizeof(*graph), GFP_KERNEL); + if (!graph) + return NULL; + + graph->nodes = kcalloc(nodes_count, sizeof(*graph->nodes), GFP_KERNEL); + if (!graph->nodes) + goto err_nodes_alloc; + graph->nodes_count = nodes_count; + + alloc_size = BITS_TO_LONGS(nodes_count * nodes_count) * + sizeof(unsigned long); + graph->edges = kzalloc(alloc_size, GFP_KERNEL); + if (!graph->edges) + goto err_edges_alloc; + + i = 0; + list_for_each_entry(objagg_obj, &objagg->obj_list, list) { + node = &graph->nodes[i++]; + node->objagg_obj = objagg_obj; + } + + /* Assemble a temporary graph. Insert edge X->Y in case Y can be + * in delta of X. + */ + for (i = 0; i < nodes_count; i++) { + for (j = 0; j < nodes_count; j++) { + if (i == j) + continue; + pnode = &graph->nodes[i]; + node = &graph->nodes[j]; + if (objagg->ops->delta_check(objagg->priv, + pnode->objagg_obj->obj, + node->objagg_obj->obj)) { + objagg_tmp_graph_edge_set(graph, i, j); + + } + } + } + return graph; + +err_edges_alloc: + kfree(graph->nodes); +err_nodes_alloc: + kfree(graph); + return NULL; +} + +static void objagg_tmp_graph_destroy(struct objagg_tmp_graph *graph) +{ + kfree(graph->edges); + kfree(graph->nodes); + kfree(graph); +} + +static int +objagg_opt_simple_greedy_fillup_hints(struct objagg_hints *objagg_hints, + struct objagg *objagg) +{ + struct objagg_hints_node *hnode, *parent_hnode; + struct objagg_tmp_graph *graph; + struct objagg_tmp_node *node; + int index; + int j; + int err; + + graph = objagg_tmp_graph_create(objagg); + if (!graph) + return -ENOMEM; + + /* Find the nodes from the ones that can accommodate most users + * and cross them out of the graph. Save them to the hint list. + */ + while ((index = objagg_tmp_graph_node_max_weight(graph)) != -1) { + node = &graph->nodes[index]; + node->crossed_out = true; + hnode = objagg_hints_node_create(objagg_hints, + node->objagg_obj, + objagg->ops->obj_size, + NULL); + if (IS_ERR(hnode)) { + err = PTR_ERR(hnode); + goto out; + } + parent_hnode = hnode; + for (j = 0; j < graph->nodes_count; j++) { + if (!objagg_tmp_graph_is_edge(graph, index, j)) + continue; + node = &graph->nodes[j]; + if (node->crossed_out) + continue; + node->crossed_out = true; + hnode = objagg_hints_node_create(objagg_hints, + node->objagg_obj, + objagg->ops->obj_size, + parent_hnode); + if (IS_ERR(hnode)) { + err = PTR_ERR(hnode); + goto out; + } + } + } + + err = 0; +out: + objagg_tmp_graph_destroy(graph); + return err; +} + +struct objagg_opt_algo { + int (*fillup_hints)(struct objagg_hints *objagg_hints, + struct objagg *objagg); +}; + +static const struct objagg_opt_algo objagg_opt_simple_greedy = { + .fillup_hints = objagg_opt_simple_greedy_fillup_hints, +}; + + +static const struct objagg_opt_algo *objagg_opt_algos[] = { + [OBJAGG_OPT_ALGO_SIMPLE_GREEDY] = &objagg_opt_simple_greedy, +}; + +static int objagg_hints_obj_cmp(struct rhashtable_compare_arg *arg, + const void *obj) +{ + struct rhashtable *ht = arg->ht; + struct objagg_hints *objagg_hints = + container_of(ht, struct objagg_hints, node_ht); + const struct objagg_ops *ops = objagg_hints->ops; + const char *ptr = obj; + + ptr += ht->p.key_offset; + return ops->hints_obj_cmp ? ops->hints_obj_cmp(ptr, arg->key) : + memcmp(ptr, arg->key, ht->p.key_len); +} + +/** + * objagg_hints_get - obtains hints instance + * @objagg: objagg instance + * @opt_algo_type: type of hints finding algorithm + * + * Note: all locking must be provided by the caller. + * + * According to the algo type, the existing objects of objagg instance + * are going to be went-through to assemble an optimal tree. We call this + * tree hints. These hints can be later on used for creation of + * a new objagg instance. There, the future object creations are going + * to be consulted with these hints in order to find out, where exactly + * the new object should be put as a root or delta. + * + * Returns a pointer to hints instance in case of success, + * otherwise it returns pointer error using ERR_PTR macro. + */ +struct objagg_hints *objagg_hints_get(struct objagg *objagg, + enum objagg_opt_algo_type opt_algo_type) +{ + const struct objagg_opt_algo *algo = objagg_opt_algos[opt_algo_type]; + struct objagg_hints *objagg_hints; + int err; + + objagg_hints = kzalloc(sizeof(*objagg_hints), GFP_KERNEL); + if (!objagg_hints) + return ERR_PTR(-ENOMEM); + + objagg_hints->ops = objagg->ops; + objagg_hints->refcount = 1; + + INIT_LIST_HEAD(&objagg_hints->node_list); + + objagg_hints->ht_params.key_len = objagg->ops->obj_size; + objagg_hints->ht_params.key_offset = + offsetof(struct objagg_hints_node, obj); + objagg_hints->ht_params.head_offset = + offsetof(struct objagg_hints_node, ht_node); + objagg_hints->ht_params.obj_cmpfn = objagg_hints_obj_cmp; + + err = rhashtable_init(&objagg_hints->node_ht, &objagg_hints->ht_params); + if (err) + goto err_rhashtable_init; + + err = algo->fillup_hints(objagg_hints, objagg); + if (err) + goto err_fillup_hints; + + if (WARN_ON(objagg_hints->node_count != objagg->obj_count)) + goto err_node_count_check; + + return objagg_hints; + +err_node_count_check: +err_fillup_hints: + objagg_hints_flush(objagg_hints); + rhashtable_destroy(&objagg_hints->node_ht); +err_rhashtable_init: + kfree(objagg_hints); + return ERR_PTR(err); +} +EXPORT_SYMBOL(objagg_hints_get); + +/** + * objagg_hints_put - puts hints instance + * @objagg_hints: objagg hints instance + * + * Note: all locking must be provided by the caller. + */ +void objagg_hints_put(struct objagg_hints *objagg_hints) +{ + if (--objagg_hints->refcount) + return; + objagg_hints_flush(objagg_hints); + rhashtable_destroy(&objagg_hints->node_ht); + kfree(objagg_hints); +} +EXPORT_SYMBOL(objagg_hints_put); + +/** + * objagg_hints_stats_get - obtains stats of the hints instance + * @objagg_hints: hints instance + * + * Note: all locking must be provided by the caller. + * + * The returned structure contains statistics of all objects + * currently in use, ordered by following rules: + * 1) Root objects are always on lower indexes than the rest. + * 2) Objects with higher delta user count are always on lower + * indexes. + * 3) In case multiple objects have the same delta user count, + * the objects are ordered by user count. + * + * Returns a pointer to stats instance in case of success, + * otherwise it returns pointer error using ERR_PTR macro. + */ +const struct objagg_stats * +objagg_hints_stats_get(struct objagg_hints *objagg_hints) +{ + struct objagg_stats *objagg_stats; + struct objagg_hints_node *hnode; + int i; + + objagg_stats = kzalloc(struct_size(objagg_stats, stats_info, + objagg_hints->node_count), + GFP_KERNEL); + if (!objagg_stats) + return ERR_PTR(-ENOMEM); + + i = 0; + list_for_each_entry(hnode, &objagg_hints->node_list, list) { + memcpy(&objagg_stats->stats_info[i], &hnode->stats_info, + sizeof(objagg_stats->stats_info[0])); + i++; + } + objagg_stats->stats_info_count = i; + + sort(objagg_stats->stats_info, objagg_stats->stats_info_count, + sizeof(struct objagg_obj_stats_info), + objagg_stats_info_sort_cmp_func, NULL); + + return objagg_stats; +} +EXPORT_SYMBOL(objagg_hints_stats_get); + MODULE_LICENSE("Dual BSD/GPL"); MODULE_AUTHOR("Jiri Pirko "); MODULE_DESCRIPTION("Object aggregation manager"); -- cgit