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, 5 insertions, 5 deletions

diff --git a/drivers/acpi/acpica/evrgnini.c b/drivers/acpi/acpica/evrgnini.c
index 2e3b0334072f..f40d271bf568 100644
--- a/drivers/acpi/acpica/evrgnini.c
+++ b/drivers/acpi/acpica/evrgnini.c
@@ -199,7 +199,7 @@ acpi_ev_pci_config_region_setup(acpi_handle handle,
                 return_ACPI_STATUS(status);
         }
 
-        parent_node = acpi_ns_get_parent_node(region_obj->region.node);
+        parent_node = region_obj->region.node->parent;
 
         /*
          * Get the _SEG and _BBN values from the device upon which the handler
@@ -248,7 +248,7 @@ acpi_ev_pci_config_region_setup(acpi_handle handle,
                                 break;
                         }
 
-                        pci_root_node = acpi_ns_get_parent_node(pci_root_node);
+                        pci_root_node = pci_root_node->parent;
                 }
 
                 /* PCI root bridge not found, use namespace root node */
@@ -280,7 +280,7 @@ acpi_ev_pci_config_region_setup(acpi_handle handle,
          */
         pci_device_node = region_obj->region.node;
         while (pci_device_node && (pci_device_node->type != ACPI_TYPE_DEVICE)) {
-                pci_device_node = acpi_ns_get_parent_node(pci_device_node);
+                pci_device_node = pci_device_node->parent;
         }
 
         if (!pci_device_node) {
@@ -521,7 +521,7 @@ acpi_ev_initialize_region(union acpi_operand_object *region_obj,
                 return_ACPI_STATUS(AE_NOT_EXIST);
         }
 
-        node = acpi_ns_get_parent_node(region_obj->region.node);
+        node = region_obj->region.node->parent;
         space_id = region_obj->region.space_id;
 
         /* Setup defaults */
@@ -654,7 +654,7 @@ acpi_ev_initialize_region(union acpi_operand_object *region_obj,
 
                 /* This node does not have the handler we need; Pop up one level */
 
-                node = acpi_ns_get_parent_node(node);
+                node = node->parent;
         }
 
         /* If we get here, there is no handler for this region */