ACPICA: Add root node optimization to internal get namespace node function.

Detect a request for the root node (a lone backslash) up front
before invoking a full namespace lookup.

Signed-off-by: Bob Moore <robert.moore@intel.com>
Signed-off-by: Lv Zheng <lv.zheng@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
This commit is contained in:
Bob Moore 2012-12-31 00:05:33 +00:00 committed by Rafael J. Wysocki
parent 04a81dce13
commit f8c9bfe461

View file

@ -671,6 +671,8 @@ acpi_ns_get_node(struct acpi_namespace_node *prefix_node,
ACPI_FUNCTION_TRACE_PTR(ns_get_node, ACPI_CAST_PTR(char, pathname));
/* Simplest case is a null pathname */
if (!pathname) {
*return_node = prefix_node;
if (!prefix_node) {
@ -679,6 +681,13 @@ acpi_ns_get_node(struct acpi_namespace_node *prefix_node,
return_ACPI_STATUS(AE_OK);
}
/* Quick check for a reference to the root */
if (ACPI_IS_ROOT_PREFIX(pathname[0]) && (!pathname[1])) {
*return_node = acpi_gbl_root_node;
return_ACPI_STATUS(AE_OK);
}
/* Convert path to internal representation */
status = acpi_ns_internalize_name(pathname, &internal_path);