+++ /dev/null
-ACPICA Trace Facility
-
-Copyright (C) 2015, Intel Corporation
-Author: Lv Zheng <lv.zheng@intel.com>
-
-
-Abstract:
-
-This document describes the functions and the interfaces of the method
-tracing facility.
-
-1. Functionalities and usage examples:
-
- ACPICA provides method tracing capability. And two functions are
- currently implemented using this capability.
-
- A. Log reducer
- ACPICA subsystem provides debugging outputs when CONFIG_ACPI_DEBUG is
- enabled. The debugging messages which are deployed via
- ACPI_DEBUG_PRINT() macro can be reduced at 2 levels - per-component
- level (known as debug layer, configured via
- /sys/module/acpi/parameters/debug_layer) and per-type level (known as
- debug level, configured via /sys/module/acpi/parameters/debug_level).
-
- But when the particular layer/level is applied to the control method
- evaluations, the quantity of the debugging outputs may still be too
- large to be put into the kernel log buffer. The idea thus is worked out
- to only enable the particular debug layer/level (normally more detailed)
- logs when the control method evaluation is started, and disable the
- detailed logging when the control method evaluation is stopped.
-
- The following command examples illustrate the usage of the "log reducer"
- functionality:
- a. Filter out the debug layer/level matched logs when control methods
- are being evaluated:
- # cd /sys/module/acpi/parameters
- # echo "0xXXXXXXXX" > trace_debug_layer
- # echo "0xYYYYYYYY" > trace_debug_level
- # echo "enable" > trace_state
- b. Filter out the debug layer/level matched logs when the specified
- control method is being evaluated:
- # cd /sys/module/acpi/parameters
- # echo "0xXXXXXXXX" > trace_debug_layer
- # echo "0xYYYYYYYY" > trace_debug_level
- # echo "\PPPP.AAAA.TTTT.HHHH" > trace_method_name
- # echo "method" > /sys/module/acpi/parameters/trace_state
- c. Filter out the debug layer/level matched logs when the specified
- control method is being evaluated for the first time:
- # cd /sys/module/acpi/parameters
- # echo "0xXXXXXXXX" > trace_debug_layer
- # echo "0xYYYYYYYY" > trace_debug_level
- # echo "\PPPP.AAAA.TTTT.HHHH" > trace_method_name
- # echo "method-once" > /sys/module/acpi/parameters/trace_state
- Where:
- 0xXXXXXXXX/0xYYYYYYYY: Refer to Documentation/acpi/debug.txt for
- possible debug layer/level masking values.
- \PPPP.AAAA.TTTT.HHHH: Full path of a control method that can be found
- in the ACPI namespace. It needn't be an entry
- of a control method evaluation.
-
- B. AML tracer
-
- There are special log entries added by the method tracing facility at
- the "trace points" the AML interpreter starts/stops to execute a control
- method, or an AML opcode. Note that the format of the log entries are
- subject to change:
- [ 0.186427] exdebug-0398 ex_trace_point : Method Begin [0xf58394d8:\_SB.PCI0.LPCB.ECOK] execution.
- [ 0.186630] exdebug-0398 ex_trace_point : Opcode Begin [0xf5905c88:If] execution.
- [ 0.186820] exdebug-0398 ex_trace_point : Opcode Begin [0xf5905cc0:LEqual] execution.
- [ 0.187010] exdebug-0398 ex_trace_point : Opcode Begin [0xf5905a20:-NamePath-] execution.
- [ 0.187214] exdebug-0398 ex_trace_point : Opcode End [0xf5905a20:-NamePath-] execution.
- [ 0.187407] exdebug-0398 ex_trace_point : Opcode Begin [0xf5905f60:One] execution.
- [ 0.187594] exdebug-0398 ex_trace_point : Opcode End [0xf5905f60:One] execution.
- [ 0.187789] exdebug-0398 ex_trace_point : Opcode End [0xf5905cc0:LEqual] execution.
- [ 0.187980] exdebug-0398 ex_trace_point : Opcode Begin [0xf5905cc0:Return] execution.
- [ 0.188146] exdebug-0398 ex_trace_point : Opcode Begin [0xf5905f60:One] execution.
- [ 0.188334] exdebug-0398 ex_trace_point : Opcode End [0xf5905f60:One] execution.
- [ 0.188524] exdebug-0398 ex_trace_point : Opcode End [0xf5905cc0:Return] execution.
- [ 0.188712] exdebug-0398 ex_trace_point : Opcode End [0xf5905c88:If] execution.
- [ 0.188903] exdebug-0398 ex_trace_point : Method End [0xf58394d8:\_SB.PCI0.LPCB.ECOK] execution.
-
- Developers can utilize these special log entries to track the AML
- interpretion, thus can aid issue debugging and performance tuning. Note
- that, as the "AML tracer" logs are implemented via ACPI_DEBUG_PRINT()
- macro, CONFIG_ACPI_DEBUG is also required to be enabled for enabling
- "AML tracer" logs.
-
- The following command examples illustrate the usage of the "AML tracer"
- functionality:
- a. Filter out the method start/stop "AML tracer" logs when control
- methods are being evaluated:
- # cd /sys/module/acpi/parameters
- # echo "0x80" > trace_debug_layer
- # echo "0x10" > trace_debug_level
- # echo "enable" > trace_state
- b. Filter out the method start/stop "AML tracer" when the specified
- control method is being evaluated:
- # cd /sys/module/acpi/parameters
- # echo "0x80" > trace_debug_layer
- # echo "0x10" > trace_debug_level
- # echo "\PPPP.AAAA.TTTT.HHHH" > trace_method_name
- # echo "method" > trace_state
- c. Filter out the method start/stop "AML tracer" logs when the specified
- control method is being evaluated for the first time:
- # cd /sys/module/acpi/parameters
- # echo "0x80" > trace_debug_layer
- # echo "0x10" > trace_debug_level
- # echo "\PPPP.AAAA.TTTT.HHHH" > trace_method_name
- # echo "method-once" > trace_state
- d. Filter out the method/opcode start/stop "AML tracer" when the
- specified control method is being evaluated:
- # cd /sys/module/acpi/parameters
- # echo "0x80" > trace_debug_layer
- # echo "0x10" > trace_debug_level
- # echo "\PPPP.AAAA.TTTT.HHHH" > trace_method_name
- # echo "opcode" > trace_state
- e. Filter out the method/opcode start/stop "AML tracer" when the
- specified control method is being evaluated for the first time:
- # cd /sys/module/acpi/parameters
- # echo "0x80" > trace_debug_layer
- # echo "0x10" > trace_debug_level
- # echo "\PPPP.AAAA.TTTT.HHHH" > trace_method_name
- # echo "opcode-opcode" > trace_state
-
- Note that all above method tracing facility related module parameters can
- be used as the boot parameters, for example:
- acpi.trace_debug_layer=0x80 acpi.trace_debug_level=0x10 \
- acpi.trace_method_name=\_SB.LID0._LID acpi.trace_state=opcode-once
-
-2. Interface descriptions:
-
- All method tracing functions can be configured via ACPI module
- parameters that are accessible at /sys/module/acpi/parameters/:
-
- trace_method_name
- The full path of the AML method that the user wants to trace.
- Note that the full path shouldn't contain the trailing "_"s in its
- name segments but may contain "\" to form an absolute path.
-
- trace_debug_layer
- The temporary debug_layer used when the tracing feature is enabled.
- Using ACPI_EXECUTER (0x80) by default, which is the debug_layer
- used to match all "AML tracer" logs.
-
- trace_debug_level
- The temporary debug_level used when the tracing feature is enabled.
- Using ACPI_LV_TRACE_POINT (0x10) by default, which is the
- debug_level used to match all "AML tracer" logs.
-
- trace_state
- The status of the tracing feature.
- Users can enable/disable this debug tracing feature by executing
- the following command:
- # echo string > /sys/module/acpi/parameters/trace_state
- Where "string" should be one of the following:
- "disable"
- Disable the method tracing feature.
- "enable"
- Enable the method tracing feature.
- ACPICA debugging messages matching
- "trace_debug_layer/trace_debug_level" during any method
- execution will be logged.
- "method"
- Enable the method tracing feature.
- ACPICA debugging messages matching
- "trace_debug_layer/trace_debug_level" during method execution
- of "trace_method_name" will be logged.
- "method-once"
- Enable the method tracing feature.
- ACPICA debugging messages matching
- "trace_debug_layer/trace_debug_level" during method execution
- of "trace_method_name" will be logged only once.
- "opcode"
- Enable the method tracing feature.
- ACPICA debugging messages matching
- "trace_debug_layer/trace_debug_level" during method/opcode
- execution of "trace_method_name" will be logged.
- "opcode-once"
- Enable the method tracing feature.
- ACPICA debugging messages matching
- "trace_debug_layer/trace_debug_level" during method/opcode
- execution of "trace_method_name" will be logged only once.
- Note that, the difference between the "enable" and other feature
- enabling options are:
- 1. When "enable" is specified, since
- "trace_debug_layer/trace_debug_level" shall apply to all control
- method evaluations, after configuring "trace_state" to "enable",
- "trace_method_name" will be reset to NULL.
- 2. When "method/opcode" is specified, if
- "trace_method_name" is NULL when "trace_state" is configured to
- these options, the "trace_debug_layer/trace_debug_level" will
- apply to all control method evaluations.
--- /dev/null
+.. SPDX-License-Identifier: GPL-2.0
+.. include:: <isonum.txt>
+
+=====================
+ACPICA Trace Facility
+=====================
+
+:Copyright: |copy| 2015, Intel Corporation
+:Author: Lv Zheng <lv.zheng@intel.com>
+
+
+Abstract
+========
+This document describes the functions and the interfaces of the
+method tracing facility.
+
+Functionalities and usage examples
+==================================
+
+ACPICA provides method tracing capability. And two functions are
+currently implemented using this capability.
+
+Log reducer
+-----------
+
+ACPICA subsystem provides debugging outputs when CONFIG_ACPI_DEBUG is
+enabled. The debugging messages which are deployed via
+ACPI_DEBUG_PRINT() macro can be reduced at 2 levels - per-component
+level (known as debug layer, configured via
+/sys/module/acpi/parameters/debug_layer) and per-type level (known as
+debug level, configured via /sys/module/acpi/parameters/debug_level).
+
+But when the particular layer/level is applied to the control method
+evaluations, the quantity of the debugging outputs may still be too
+large to be put into the kernel log buffer. The idea thus is worked out
+to only enable the particular debug layer/level (normally more detailed)
+logs when the control method evaluation is started, and disable the
+detailed logging when the control method evaluation is stopped.
+
+The following command examples illustrate the usage of the "log reducer"
+functionality:
+
+a. Filter out the debug layer/level matched logs when control methods
+ are being evaluated::
+
+ # cd /sys/module/acpi/parameters
+ # echo "0xXXXXXXXX" > trace_debug_layer
+ # echo "0xYYYYYYYY" > trace_debug_level
+ # echo "enable" > trace_state
+
+b. Filter out the debug layer/level matched logs when the specified
+ control method is being evaluated::
+
+ # cd /sys/module/acpi/parameters
+ # echo "0xXXXXXXXX" > trace_debug_layer
+ # echo "0xYYYYYYYY" > trace_debug_level
+ # echo "\PPPP.AAAA.TTTT.HHHH" > trace_method_name
+ # echo "method" > /sys/module/acpi/parameters/trace_state
+
+c. Filter out the debug layer/level matched logs when the specified
+ control method is being evaluated for the first time::
+
+ # cd /sys/module/acpi/parameters
+ # echo "0xXXXXXXXX" > trace_debug_layer
+ # echo "0xYYYYYYYY" > trace_debug_level
+ # echo "\PPPP.AAAA.TTTT.HHHH" > trace_method_name
+ # echo "method-once" > /sys/module/acpi/parameters/trace_state
+
+Where:
+ 0xXXXXXXXX/0xYYYYYYYY
+ Refer to Documentation/acpi/debug.txt for possible debug layer/level
+ masking values.
+ \PPPP.AAAA.TTTT.HHHH
+ Full path of a control method that can be found in the ACPI namespace.
+ It needn't be an entry of a control method evaluation.
+
+AML tracer
+----------
+
+There are special log entries added by the method tracing facility at
+the "trace points" the AML interpreter starts/stops to execute a control
+method, or an AML opcode. Note that the format of the log entries are
+subject to change::
+
+ [ 0.186427] exdebug-0398 ex_trace_point : Method Begin [0xf58394d8:\_SB.PCI0.LPCB.ECOK] execution.
+ [ 0.186630] exdebug-0398 ex_trace_point : Opcode Begin [0xf5905c88:If] execution.
+ [ 0.186820] exdebug-0398 ex_trace_point : Opcode Begin [0xf5905cc0:LEqual] execution.
+ [ 0.187010] exdebug-0398 ex_trace_point : Opcode Begin [0xf5905a20:-NamePath-] execution.
+ [ 0.187214] exdebug-0398 ex_trace_point : Opcode End [0xf5905a20:-NamePath-] execution.
+ [ 0.187407] exdebug-0398 ex_trace_point : Opcode Begin [0xf5905f60:One] execution.
+ [ 0.187594] exdebug-0398 ex_trace_point : Opcode End [0xf5905f60:One] execution.
+ [ 0.187789] exdebug-0398 ex_trace_point : Opcode End [0xf5905cc0:LEqual] execution.
+ [ 0.187980] exdebug-0398 ex_trace_point : Opcode Begin [0xf5905cc0:Return] execution.
+ [ 0.188146] exdebug-0398 ex_trace_point : Opcode Begin [0xf5905f60:One] execution.
+ [ 0.188334] exdebug-0398 ex_trace_point : Opcode End [0xf5905f60:One] execution.
+ [ 0.188524] exdebug-0398 ex_trace_point : Opcode End [0xf5905cc0:Return] execution.
+ [ 0.188712] exdebug-0398 ex_trace_point : Opcode End [0xf5905c88:If] execution.
+ [ 0.188903] exdebug-0398 ex_trace_point : Method End [0xf58394d8:\_SB.PCI0.LPCB.ECOK] execution.
+
+Developers can utilize these special log entries to track the AML
+interpretion, thus can aid issue debugging and performance tuning. Note
+that, as the "AML tracer" logs are implemented via ACPI_DEBUG_PRINT()
+macro, CONFIG_ACPI_DEBUG is also required to be enabled for enabling
+"AML tracer" logs.
+
+The following command examples illustrate the usage of the "AML tracer"
+functionality:
+
+a. Filter out the method start/stop "AML tracer" logs when control
+ methods are being evaluated::
+
+ # cd /sys/module/acpi/parameters
+ # echo "0x80" > trace_debug_layer
+ # echo "0x10" > trace_debug_level
+ # echo "enable" > trace_state
+
+b. Filter out the method start/stop "AML tracer" when the specified
+ control method is being evaluated::
+
+ # cd /sys/module/acpi/parameters
+ # echo "0x80" > trace_debug_layer
+ # echo "0x10" > trace_debug_level
+ # echo "\PPPP.AAAA.TTTT.HHHH" > trace_method_name
+ # echo "method" > trace_state
+
+c. Filter out the method start/stop "AML tracer" logs when the specified
+ control method is being evaluated for the first time::
+
+ # cd /sys/module/acpi/parameters
+ # echo "0x80" > trace_debug_layer
+ # echo "0x10" > trace_debug_level
+ # echo "\PPPP.AAAA.TTTT.HHHH" > trace_method_name
+ # echo "method-once" > trace_state
+
+d. Filter out the method/opcode start/stop "AML tracer" when the
+ specified control method is being evaluated::
+
+ # cd /sys/module/acpi/parameters
+ # echo "0x80" > trace_debug_layer
+ # echo "0x10" > trace_debug_level
+ # echo "\PPPP.AAAA.TTTT.HHHH" > trace_method_name
+ # echo "opcode" > trace_state
+
+e. Filter out the method/opcode start/stop "AML tracer" when the
+ specified control method is being evaluated for the first time::
+
+ # cd /sys/module/acpi/parameters
+ # echo "0x80" > trace_debug_layer
+ # echo "0x10" > trace_debug_level
+ # echo "\PPPP.AAAA.TTTT.HHHH" > trace_method_name
+ # echo "opcode-opcode" > trace_state
+
+Note that all above method tracing facility related module parameters can
+be used as the boot parameters, for example::
+
+ acpi.trace_debug_layer=0x80 acpi.trace_debug_level=0x10 \
+ acpi.trace_method_name=\_SB.LID0._LID acpi.trace_state=opcode-once
+
+
+Interface descriptions
+======================
+
+All method tracing functions can be configured via ACPI module
+parameters that are accessible at /sys/module/acpi/parameters/:
+
+trace_method_name
+ The full path of the AML method that the user wants to trace.
+
+ Note that the full path shouldn't contain the trailing "_"s in its
+ name segments but may contain "\" to form an absolute path.
+
+trace_debug_layer
+ The temporary debug_layer used when the tracing feature is enabled.
+
+ Using ACPI_EXECUTER (0x80) by default, which is the debug_layer
+ used to match all "AML tracer" logs.
+
+trace_debug_level
+ The temporary debug_level used when the tracing feature is enabled.
+
+ Using ACPI_LV_TRACE_POINT (0x10) by default, which is the
+ debug_level used to match all "AML tracer" logs.
+
+trace_state
+ The status of the tracing feature.
+
+ Users can enable/disable this debug tracing feature by executing
+ the following command::
+
+ # echo string > /sys/module/acpi/parameters/trace_state
+
+Where "string" should be one of the following:
+
+"disable"
+ Disable the method tracing feature.
+
+"enable"
+ Enable the method tracing feature.
+
+ ACPICA debugging messages matching "trace_debug_layer/trace_debug_level"
+ during any method execution will be logged.
+
+"method"
+ Enable the method tracing feature.
+
+ ACPICA debugging messages matching "trace_debug_layer/trace_debug_level"
+ during method execution of "trace_method_name" will be logged.
+
+"method-once"
+ Enable the method tracing feature.
+
+ ACPICA debugging messages matching "trace_debug_layer/trace_debug_level"
+ during method execution of "trace_method_name" will be logged only once.
+
+"opcode"
+ Enable the method tracing feature.
+
+ ACPICA debugging messages matching "trace_debug_layer/trace_debug_level"
+ during method/opcode execution of "trace_method_name" will be logged.
+
+"opcode-once"
+ Enable the method tracing feature.
+
+ ACPICA debugging messages matching "trace_debug_layer/trace_debug_level"
+ during method/opcode execution of "trace_method_name" will be logged only
+ once.
+
+Note that, the difference between the "enable" and other feature
+enabling options are:
+
+1. When "enable" is specified, since
+ "trace_debug_layer/trace_debug_level" shall apply to all control
+ method evaluations, after configuring "trace_state" to "enable",
+ "trace_method_name" will be reset to NULL.
+2. When "method/opcode" is specified, if
+ "trace_method_name" is NULL when "trace_state" is configured to
+ these options, the "trace_debug_layer/trace_debug_level" will
+ apply to all control method evaluations.
projects / linux-2.6-block.git / commitdiff