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Diffstat (limited to 'Documentation/acpi/method-tracing.txt')
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diff --git a/Documentation/acpi/method-tracing.txt b/Documentation/acpi/method-tracing.txt deleted file mode 100644 index 0aba14c8f459..000000000000 --- a/Documentation/acpi/method-tracing.txt +++ /dev/null @@ -1,192 +0,0 @@ -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. |