ACPICA: Performance enhancement for namespace search and access

This change enhances the performance of namespace searches and
walks by adding a backpointer to the parent in each namespace
node. On large namespaces, this change can improve overall ACPI
performance by up to 9X.  Adding a pointer to each namespace node
increases the overall size of the internal namespace by about 5%,
since each namespace entry usually consists of both a namespace
node and an ACPI operand object.

Signed-off-by: Alexey Starikovskiy <astarikovskiy@suse.de>
Signed-off-by: Bob Moore <robert.moore@intel.com>
Signed-off-by: Lin Ming <ming.m.lin@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>

1 files changed, 3 insertions, 12 deletions

diff --git a/drivers/acpi/acpica/nswalk.c b/drivers/acpi/acpica/nswalk.c
index 00e79fb26029..2cd5be8fe10f 100644
--- a/drivers/acpi/acpica/nswalk.c
+++ b/drivers/acpi/acpica/nswalk.c
@@ -79,15 +79,6 @@ struct acpi_namespace_node *acpi_ns_get_next_node(struct acpi_namespace_node
                 return parent_node->child;
         }
 
-        /*
-         * Get the next node.
-         *
-         * If we are at the end of this peer list, return NULL
-         */
-        if (child_node->flags & ANOBJ_END_OF_PEER_LIST) {
-                return NULL;
-        }
-
         /* Otherwise just return the next peer */
 
         return child_node->peer;
@@ -146,9 +137,9 @@ struct acpi_namespace_node *acpi_ns_get_next_node_typed(acpi_object_type type,
                         return (next_node);
                 }
 
-                /* Otherwise, move on to the next node */
+                /* Otherwise, move on to the next peer node */
 
-                next_node = acpi_ns_get_next_valid_node(next_node);
+                next_node = next_node->peer;
         }
 
         /* Not found */
@@ -355,7 +346,7 @@ acpi_ns_walk_namespace(acpi_object_type type,
                          */
                         level--;
                         child_node = parent_node;
-                        parent_node = acpi_ns_get_parent_node(parent_node);
+                        parent_node = parent_node->parent;
 
                         node_previously_visited = TRUE;
                 }