From e5227865e1f4a428e1e168dc141254a84c219226 Mon Sep 17 00:00:00 2001 From: Mathieu Desnoyers Date: Thu, 8 Mar 2012 22:23:33 -0500 Subject: [PATCH] rcuja: Increase granularity Signed-off-by: Mathieu Desnoyers --- rcuja/design.txt | 12 ++++---- rcuja/rcuja.c | 74 ++++++++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 80 insertions(+), 6 deletions(-) diff --git a/rcuja/design.txt b/rcuja/design.txt index 775ec97..947f61a 100644 --- a/rcuja/design.txt +++ b/rcuja/design.txt @@ -223,16 +223,16 @@ least-significant bits. Types of children: enum child_type { - LINEAR = 0, /* Type A */ - /* 32-bit: 1 to 12 children, 32 to 64 bytes */ - /* 64-bit: 1 to 14 children, 32 to 128 bytes */ - BITMAP = 1, /* Type B */ + RCU_JA_LINEAR = 0, /* Type A */ + /* 32-bit: 1 to 12 children, 8 to 64 bytes */ + /* 64-bit: 1 to 14 children, 16 to 128 bytes */ + RCU_JA_BITMAP = 1, /* Type B */ /* 32-bit: 13 to 120 children, 128 to 512 bytes */ /* 64-bit: 15 to 124 children, 256 to 1024 bytes */ - PIGEON = 2, /* Type C */ + RCU_JA_PIGEON = 2, /* Type C */ /* 32-bit: 121 to 256 children, 1024 bytes */ /* 64-bit: 125 to 256 children, 2048 bytes */ - LEAF = 3, /* Leaf node */ + /* Leaf nodes are implicit from their height in the tree */ }; If entire pointer is NULL, children is empty. diff --git a/rcuja/rcuja.c b/rcuja/rcuja.c index 6dcd9c6..012b874 100644 --- a/rcuja/rcuja.c +++ b/rcuja/rcuja.c @@ -20,6 +20,80 @@ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA */ +#include #include #include "rcuja-internal.h" +enum rcu_ja_child_type { + RCU_JA_LINEAR = 0, /* Type A */ + /* 32-bit: 1 to 12 children, 8 to 64 bytes */ + /* 64-bit: 1 to 14 children, 16 to 128 bytes */ + RCU_JA_BITMAP = 1, /* Type B */ + /* 32-bit: 13 to 120 children, 128 to 512 bytes */ + /* 64-bit: 15 to 124 children, 256 to 1024 bytes */ + RCU_JA_PIGEON = 2, /* Type C */ + /* 32-bit: 121 to 256 children, 1024 bytes */ + /* 64-bit: 125 to 256 children, 2048 bytes */ + /* Leaf nodes are implicit from their height in the tree */ +}; + +struct rcu_ja_type_select { + enum rcu_ja_child_type type; + uint16_t max_nr_child; /* 1 to 256 */ + uint16_t node_order; /* node size is (1 << node_order), in bytes */ +}; + +/* + * Iteration on the array to find the right node size for the number of + * children stops when it reaches max_nr_child == 0 (this is the largest + * possible node size, which contains 256 children). + */ +const struct rcu_ja_type_select ja_select_u32[] = { + { .type = RCU_JA_LINEAR, .max_nr_child = 1, .node_order = 3, }, + { .type = RCU_JA_LINEAR, .max_nr_child = 3, .node_order = 4, }, + { .type = RCU_JA_LINEAR, .max_nr_child = 6, .node_order = 5, }, + { .type = RCU_JA_LINEAR, .max_nr_child = 12, .node_order = 6, }, + + { .type = RCU_JA_BITMAP, .max_nr_child = 24, .node_order = 7, }, + { .type = RCU_JA_BITMAP, .max_nr_child = 56, .node_order = 8, }, + { .type = RCU_JA_BITMAP, .max_nr_child = 120, .node_order = 9, }, + + { .type = RCU_JA_PIGEON, .max_nr_child = 256, .node_order = 10, }, +}; + +const struct rcu_ja_type_select ja_select_u64[] = { + { .type = RCU_JA_LINEAR, .max_nr_child = 1, .node_order = 4, }, + { .type = RCU_JA_LINEAR, .max_nr_child = 3, .node_order = 5, }, + { .type = RCU_JA_LINEAR, .max_nr_child = 7, .node_order = 6, }, + { .type = RCU_JA_LINEAR, .max_nr_child = 14, .node_order = 7, }, + + { .type = RCU_JA_BITMAP, .max_nr_child = 28, .node_order = 8, }, + { .type = RCU_JA_BITMAP, .max_nr_child = 60, .node_order = 9, }, + { .type = RCU_JA_BITMAP, .max_nr_child = 124, .node_order = 10, }, + + { .type = RCU_JA_PIGEON, .max_nr_child = 256, .node_order = 11, }, +}; + +/* + * The rcu_ja_node starts with a byte counting the number of children in + * the node. Then, the node-specific data is placed. + * TODO: where should we put the mutex for the node ? + * -> mutex could be a 0-value node count. + * TODO: where do we keep nr children for pigeon ? + */ +struct rcu_ja_node { + char data[]; +}; + +struct rcu_ja_node *create_rcu_ja_node(struct rcu_ja_type_select *sel) +{ + return zmalloc(1 << sel->node_order); +} + +void free_rcu_ja_node(struct rcu_ja_node *node) +{ + free(node); +} + + + -- 2.34.1