From e694c94bf7221d94232743eb162c227975cd91e8 Mon Sep 17 00:00:00 2001 From: Joel Sherrill Date: Thu, 14 Sep 2006 15:06:38 +0000 Subject: 2006-09-14 Joel Sherrill * new_chapters/Makefile.am, new_chapters/gen_section, new_chapters/new_chapters.texi, user/Makefile.am, user/c_user.texi, user/dirstat.texi: Promote CPU Usage to first class citizen. Rename to start with rtems_ and include documentation in user guide. * user/cpuuse.t: New file. * new_chapters/cpuuse.t: Removed. --- doc/new_chapters/cpuuse.t | 142 ---------------------------------------------- 1 file changed, 142 deletions(-) delete mode 100644 doc/new_chapters/cpuuse.t (limited to 'doc/new_chapters/cpuuse.t') diff --git a/doc/new_chapters/cpuuse.t b/doc/new_chapters/cpuuse.t deleted file mode 100644 index a83ead2be9..0000000000 --- a/doc/new_chapters/cpuuse.t +++ /dev/null @@ -1,142 +0,0 @@ -@c -@c COPYRIGHT (c) 1988-2002. -@c On-Line Applications Research Corporation (OAR). -@c All rights reserved. -@c -@c $Id$ -@c - -@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{CPU_usage_Dump} - Report CPU Usage Statistics -@item @code{CPU_usage_Reset} - Reset CPU Usage Statistics -@end itemize - -@section Background - -@section Operations - -@section Report CPU Usage Statistics - -@subsection Reporting Period Statistics - -The application may dynamically report the CPU usage for every -task in the system by calling the @code{CPU_usage_Dump} 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: - -@example -@group -CPU Usage by thread - ID NAME TICKS PERCENT -0x04010001 IDLE 0 0.000 -0x08010002 TA1 1203 0.748 -0x08010003 TA2 203 0.126 -0x08010004 TA3 202 0.126 - -Ticks since last reset = 1600 - -Total Units = 1608 -@end group -@end example - -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. - -@section Reset CPU Usage Statistics - -Invoking the @code{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_Dump - Report CPU Usage Statistics - -@subheading CALLING SEQUENCE: - -@ifset is-C -@example -void CPU_usage_Dump( void ); -@end example -@end ifset - -@ifset is-Ada -@example -An Ada interface is not currently available. -@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: - -NONE - -@page -@subsection CPU_usage_Reset - Reset CPU Usage Statistics - -@subheading CALLING SEQUENCE: - -@ifset is-C -@example -void CPU_usage_Reset( void ); -@end example -@end ifset - -@ifset is-Ada -@example -An Ada interface is not currently available. -@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