litmus-rt.git - The LITMUS^RT kernel.

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author	Gregory Haskins <ghaskins@novell.com>	2008-01-25 15:08:09 -0500
committer	Ingo Molnar <mingo@elte.hu>	2008-01-25 15:08:09 -0500
commit	e7693a362ec84bb5b6fd441d8a8b4b9d568a7a0c (patch)
tree	078940540641a59aaf199695bfc6de3f062a987b /block
parent	697f0a487f294e634a342764472b79375bb3158a (diff)

sched: de-SCHED_OTHER-ize the RT path

The current wake-up code path tries to determine if it can optimize the wake-up to "this_cpu" by computing load calculations. The problem is that these calculations are only relevant to SCHED_OTHER tasks where load is king. For RT tasks, priority is king. So the load calculation is completely wasted bandwidth. Therefore, we create a new sched_class interface to help with pre-wakeup routing decisions and move the load calculation as a function of CFS task's class. Signed-off-by: Gregory Haskins <ghaskins@novell.com> Signed-off-by: Steven Rostedt <srostedt@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>

Diffstat (limited to 'block')

0 files changed, 0 insertions, 0 deletions

/****************************************************************************** * * Module Name: dscontrol - Support for execution control opcodes - * if/else/while/return * *****************************************************************************/ /* * Copyright (C) 2000 - 2016, Intel Corp. * All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions, and the following disclaimer, * without modification. * 2. Redistributions in binary form must reproduce at minimum a disclaimer * substantially similar to the "NO WARRANTY" disclaimer below * ("Disclaimer") and any redistribution must be conditioned upon * including a substantially similar Disclaimer requirement for further * binary redistribution. * 3. Neither the names of the above-listed copyright holders nor the names * of any contributors may be used to endorse or promote products derived * from this software without specific prior written permission. * * Alternatively, this software may be distributed under the terms of the * GNU General Public License ("GPL") version 2 as published by the Free * Software Foundation. * * NO WARRANTY * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT * HOLDERS OR CONTRIBUTORS BE LIABLE FOR SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE * POSSIBILITY OF SUCH DAMAGES. */ #include <acpi/acpi.h> #include "accommon.h" #include "amlcode.h" #include "acdispat.h" #include "acinterp.h" #include "acdebug.h" #define _COMPONENT ACPI_DISPATCHER ACPI_MODULE_NAME("dscontrol") /******************************************************************************* * * FUNCTION: acpi_ds_exec_begin_control_op * * PARAMETERS: walk_list - The list that owns the walk stack * op - The control Op * * RETURN: Status * * DESCRIPTION: Handles all control ops encountered during control method * execution. * ******************************************************************************/ acpi_status acpi_ds_exec_begin_control_op(struct acpi_walk_state *walk_state, union acpi_parse_object *op) { acpi_status status = AE_OK; union acpi_generic_state *control_state; ACPI_FUNCTION_NAME(ds_exec_begin_control_op); ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH, "Op=%p Opcode=%2.2X State=%p\n", op, op->common.aml_opcode, walk_state)); switch (op->common.aml_opcode) { 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 * to handle nesting. */ control_state = acpi_ut_create_control_state(); if (!control_state) { status = AE_NO_MEMORY; break; } /* * Save a pointer to the predicate for multiple executions * of a loop */ control_state->control.aml_predicate_start = walk_state->parser_state.aml - 1; control_state->control.package_end = walk_state->parser_state.pkg_end; control_state->control.opcode = op->common.aml_opcode; /* Push the control state on this walk's control stack */ acpi_ut_push_generic_state(&walk_state->control_state, control_state); break; case AML_ELSE_OP: /* Predicate is in the state object */ /* If predicate is true, the IF was executed, ignore ELSE part */ if (walk_state->last_predicate) { status = AE_CTRL_TRUE; } break; case AML_RETURN_OP: break; default: break; } return (status); } /******************************************************************************* * * FUNCTION: acpi_ds_exec_end_control_op * * PARAMETERS: walk_list - The list that owns the walk stack * op - The control Op * * RETURN: Status * * DESCRIPTION: Handles all control ops encountered during control method * execution. * ******************************************************************************/ acpi_status acpi_ds_exec_end_control_op(struct acpi_walk_state *walk_state, union acpi_parse_object *op) { acpi_status status = AE_OK; union acpi_generic_state *control_state; ACPI_FUNCTION_NAME(ds_exec_end_control_op); switch (op->common.aml_opcode) { case AML_IF_OP: ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH, "[IF_OP] Op=%p\n", op)); /* * Save the result of the predicate in case there is an * ELSE to come */ walk_state->last_predicate = (u8)walk_state->control_state->common.value; /* * Pop the control state that was created at the start * of the IF and free it */ control_state = acpi_ut_pop_generic_state(&walk_state->control_state); acpi_ut_delete_generic_state(control_state); break; case AML_ELSE_OP: break; case AML_WHILE_OP: ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH, "[WHILE_OP] Op=%p\n", op)); control_state = walk_state->control_state; if (control_state->common.value) { /* Predicate was true, the body of the loop was just executed */ /* * This loop counter mechanism allows the interpreter to escape * possibly infinite loops. This can occur in poorly written AML * when the hardware does not respond within a while loop and the * loop does not implement a timeout. */ control_state->control.loop_count++; if (control_state->control.loop_count > acpi_gbl_max_loop_iterations) { status = AE_AML_INFINITE_LOOP; break; } /* * Go back and evaluate the predicate and maybe execute the loop * another time */ status = AE_CTRL_PENDING; walk_state->aml_last_while = 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)); /* Pop this control state and free it */ control_state = acpi_ut_pop_generic_state(&walk_state->control_state); acpi_ut_delete_generic_state(control_state); break; case AML_RETURN_OP: ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH, "[RETURN_OP] Op=%p Arg=%p\n", op, op->common.value.arg)); /* * One optional operand -- the return value * It can be either an immediate operand or a result that * has been bubbled up the tree */ if (op->common.value.arg) { /* Since we have a real Return(), delete any implicit return */ acpi_ds_clear_implicit_return(walk_state); /* Return statement has an immediate operand */ status = acpi_ds_create_operands(walk_state, op->common.value.arg); if (ACPI_FAILURE(status)) { return (status); } /* * If value being returned is a Reference (such as * an arg or local), resolve it now because it may * cease to exist at the end of the method. */ status = acpi_ex_resolve_to_value(&walk_state->operands[0], walk_state); if (ACPI_FAILURE(status)) { return (status); } /* * Get the return value and save as the last result * value. This is the only place where walk_state->return_desc * is set to anything other than zero! */ walk_state->return_desc = walk_state->operands[0]; } else if (walk_state->result_count) { /* Since we have a real Return(), delete any implicit return */ acpi_ds_clear_implicit_return(walk_state); /* * The return value has come from a previous calculation. * * If value being returned is a Reference (such as * an arg or local), resolve it now because it may * cease to exist at the end of the method. * * Allow references created by the Index operator to return * unchanged. */ if ((ACPI_GET_DESCRIPTOR_TYPE (walk_state->results->results.obj_desc[0]) == ACPI_DESC_TYPE_OPERAND) && ((walk_state->results->results.obj_desc[0])-> common.type == ACPI_TYPE_LOCAL_REFERENCE) && ((walk_state->results->results.obj_desc[0])-> reference.class != ACPI_REFCLASS_INDEX)) { status = acpi_ex_resolve_to_value(&walk_state-> results->results. obj_desc[0], walk_state); if (ACPI_FAILURE(status)) { return (status); } } walk_state->return_desc = walk_state->results->results.obj_desc[0]; } else { /* No return operand */ if (walk_state->num_operands) { acpi_ut_remove_reference(walk_state-> operands[0]); } walk_state->operands[0] = NULL; walk_state->num_operands = 0; walk_state->return_desc = NULL; } ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH, "Completed RETURN_OP State=%p, RetVal=%p\n", walk_state, walk_state->return_desc)); /* End the control method execution right now */ status = AE_CTRL_TERMINATE; break; case AML_NOOP_OP: /* Just do nothing! */ break; case AML_BREAK_POINT_OP: acpi_db_signal_break_point(walk_state); /* Call to the OSL in case OS wants a piece of the action */ status = acpi_os_signal(ACPI_SIGNAL_BREAKPOINT, "Executed AML Breakpoint opcode"); break; case AML_BREAK_OP: case AML_CONTINUE_OP: /* ACPI 2.0 */ /* Pop and delete control states until we find a while */ while (walk_state->control_state && (walk_state->control_state->control.opcode != AML_WHILE_OP)) { control_state = acpi_ut_pop_generic_state(&walk_state-> control_state); acpi_ut_delete_generic_state(control_state); } /* No while found? */ if (!walk_state->control_state) { return (AE_AML_NO_WHILE); } /* Was: walk_state->aml_last_while = walk_state->control_state->Control.aml_predicate_start; */ walk_state->aml_last_while = walk_state->control_state->control.package_end; /* Return status depending on opcode */ if (op->common.aml_opcode == AML_BREAK_OP) { status = AE_CTRL_BREAK; } else { status = AE_CTRL_CONTINUE; } break; default: ACPI_ERROR((AE_INFO, "Unknown control opcode=0x%X Op=%p", op->common.aml_opcode, op)); status = AE_AML_BAD_OPCODE; break; } return (status); }


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