From 48a7fa31f918a6fc88719b3c9393a9ba2829f42a Mon Sep 17 00:00:00 2001 From: Joel Sherrill Date: Tue, 15 Nov 2016 10:37:59 -0600 Subject: Remove texinfo format documentation. Replaced by Sphinx formatted documentation. closes #2812. --- doc/user/cpuuse.t | 160 ------------------------------------------------------ 1 file changed, 160 deletions(-) delete mode 100644 doc/user/cpuuse.t (limited to 'doc/user/cpuuse.t') diff --git a/doc/user/cpuuse.t b/doc/user/cpuuse.t deleted file mode 100644 index f3035d1daf..0000000000 --- a/doc/user/cpuuse.t +++ /dev/null @@ -1,160 +0,0 @@ -@c -@c COPYRIGHT (c) 1988-2007. -@c On-Line Applications Research Corporation (OAR). -@c All rights reserved. - -@chapter CPU Usage Statistics - -@section Introduction - -The CPU usage statistics manager is an RTEMS support -component that provides a convenient way to manipulate -the CPU usage information associated with each task -The routines provided by the CPU usage statistics manager are: - -@itemize @bullet -@item @code{@value{DIRPREFIX}cpu_usage_report} - Report CPU Usage Statistics -@item @code{@value{DIRPREFIX}cpu_usage_reset} - Reset CPU Usage Statistics -@end itemize - -@section Background - -When analyzing and debugging real-time applications, it is important -to be able to know how much CPU time each task in the system consumes. -This support component provides a mechanism to easily obtain this -information with little burden placed on the target. - -The raw data is gathered as part of performing a context switch. RTEMS -keeps track of how many clock ticks have occurred which the task being -switched out has been executing. If the task has been running less than -1 clock tick, then for the purposes of the statistics, it is assumed to -have executed 1 clock tick. This results in some inaccuracy but the -alternative is for the task to have appeared to execute 0 clock ticks. - -RTEMS versions newer than the 4.7 release series, support the ability -to obtain timestamps with nanosecond granularity if the BSP provides -support. It is a desirable enhancement to change the way the usage -data is gathered to take advantage of this recently added capability. -Please consider sponsoring the core RTEMS development team to add -this capability. - -@section Operations - -@subsection Report CPU Usage Statistics - -The application may dynamically report the CPU usage for every -task in the system by calling the -@code{@value{DIRPREFIX}cpu_usage_report} routine. -This routine prints a table with the following information per task: - -@itemize @bullet -@item task id -@item task name -@item number of clock ticks executed -@item percentage of time consumed by this task -@end itemize - -The following is an example of the report generated: - -@smallexample -@group -------------------------------------------------------------------------------- - CPU USAGE BY THREAD -------------+----------------------------------------+---------------+--------- - ID | NAME | SECONDS | PERCENT -------------+----------------------------------------+---------------+--------- - 0x04010001 | IDLE | 0 | 0.000 - 0x08010002 | TA1 | 1203 | 0.748 - 0x08010003 | TA2 | 203 | 0.126 - 0x08010004 | TA3 | 202 | 0.126 -------------+----------------------------------------+---------------+--------- - TICKS SINCE LAST SYSTEM RESET: 1600 - TOTAL UNITS: 1608 -------------------------------------------------------------------------------- -@end group -@end smallexample - -Notice that the "TOTAL UNITS" is greater than the ticks per reset. -This is an artifact of the way in which RTEMS keeps track of CPU -usage. When a task is context switched into the CPU, the number -of clock ticks it has executed is incremented. While the task -is executing, this number is incremented on each clock tick. -Otherwise, if a task begins and completes execution between -successive clock ticks, there would be no way to tell that it -executed at all. - -Another thing to keep in mind when looking at idle time, is that -many systems -- especially during debug -- have a task providing -some type of debug interface. It is usually fine to think of the -total idle time as being the sum of the IDLE task and a debug -task that will not be included in a production build of an application. - -@subsection Reset CPU Usage Statistics - -Invoking the @code{@value{DIRPREFIX}cpu_usage_reset} routine resets -the CPU usage statistics for all tasks in the system. - -@section Directives - -This section details the CPU usage statistics manager's directives. -A subsection is dedicated to each of this manager's directives -and describes the calling sequence, related constants, usage, -and status codes. - -@page -@subsection cpu_usage_report - Report CPU Usage Statistics - -@subheading CALLING SEQUENCE: - -@ifset is-C -@example -void rtems_cpu_usage_report( void ); -@end example -@end ifset - -@ifset is-Ada -@example -procedure CPU_Usage_Report; -@end example -@end ifset - -@subheading STATUS CODES: NONE - -@subheading DESCRIPTION: - -This routine prints out a table detailing the CPU usage statistics for -all tasks in the system. - -@subheading NOTES: - -The table is printed using the @code{printk} routine. - -@page -@subsection cpu_usage_reset - Reset CPU Usage Statistics - -@subheading CALLING SEQUENCE: - -@ifset is-C -@example -void rtems_cpu_usage_reset( void ); -@end example -@end ifset - -@ifset is-Ada -@example -procedure CPU_Usage_Reset; -@end example -@end ifset - -@subheading STATUS CODES: NONE - -@subheading DESCRIPTION: - -This routine re-initializes the CPU usage statistics for all tasks -in the system to their initial state. The initial state is that -a task has not executed and thus has consumed no CPU time. -default state which is when zero period executions have occurred. - -@subheading NOTES: - -NONE -- cgit v1.2.3