From 96411a630412f057d365aa1e9de7d23c069d627a Mon Sep 17 00:00:00 2001 From: Bob Moore Date: Wed, 12 Nov 2008 15:02:00 +0800 Subject: [PATCH] ACPICA: Optimize execution of AML While loops Previously, a control state object was allocated and freed for each execution of the loop. The optimization is to simply reuse the control state for each iteration. This speeds up the raw loop execution time by about 5%. Signed-off-by: Bob Moore Signed-off-by: Lin Ming Signed-off-by: Len Brown --- drivers/acpi/dispatcher/dsopcode.c | 29 +++++++++++++++++++++++++---- 1 file changed, 25 insertions(+), 4 deletions(-) diff --git a/drivers/acpi/dispatcher/dsopcode.c b/drivers/acpi/dispatcher/dsopcode.c index 69fae5905bb8..5cd406676c2c 100644 --- a/drivers/acpi/dispatcher/dsopcode.c +++ b/drivers/acpi/dispatcher/dsopcode.c @@ -1140,9 +1140,28 @@ acpi_ds_exec_begin_control_op(struct acpi_walk_state *walk_state, op->common.aml_opcode, walk_state)); switch (op->common.aml_opcode) { - case AML_IF_OP: case AML_WHILE_OP: + /* + * If this is an additional iteration of a while loop, continue. + * There is no need to allocate a new control state. + */ + if (walk_state->control_state) { + if (walk_state->control_state->control.aml_predicate_start + == (walk_state->parser_state.aml - 1)) { + + /* Reset the state to start-of-loop */ + + walk_state->control_state->common.state = + ACPI_CONTROL_CONDITIONAL_EXECUTING; + break; + } + } + + /*lint -fallthrough */ + + case AML_IF_OP: + /* * IF/WHILE: Create a new control state to manage these * constructs. We need to manage these as a stack, in order @@ -1248,8 +1267,13 @@ acpi_ds_exec_end_control_op(struct acpi_walk_state * walk_state, /* Predicate was true, go back and evaluate it again! */ status = AE_CTRL_PENDING; + walk_state->aml_last_while = + walk_state->control_state->control.aml_predicate_start; + break; } + /* Predicate was false, terminate this while loop */ + ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH, "[WHILE_OP] termination! Op=%p\n", op)); @@ -1257,9 +1281,6 @@ acpi_ds_exec_end_control_op(struct acpi_walk_state * walk_state, control_state = acpi_ut_pop_generic_state(&walk_state->control_state); - - walk_state->aml_last_while = - control_state->control.aml_predicate_start; acpi_ut_delete_generic_state(control_state); break;