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author | Joel Sherrill <joel.sherrill@OARcorp.com> | 2004-09-29 20:34:01 +0000 |
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committer | Joel Sherrill <joel.sherrill@OARcorp.com> | 2004-09-29 20:34:01 +0000 |
commit | ac200c1ba1ed071354d578bdc2e7feec81b10baf (patch) | |
tree | b78e6484cb446bdfacc8f5e36e51579e75059067 /cpukit/libmisc/cpuuse/README | |
parent | 2004-09-29 Joel Sherrill <joel@OARcorp.com> (diff) | |
download | rtems-ac200c1ba1ed071354d578bdc2e7feec81b10baf.tar.bz2 |
2004-09-29 Joel Sherrill <joel@OARcorp.com>
* configure.ac, libmisc/cpuuse/README, libmisc/stackchk/README,
librpc/src/xdr/xdr_float.c, score/cpu/Makefile.am,
score/include/rtems/score/mppkt.h: i960 obsoleted and all references
removed.
Diffstat (limited to '')
-rw-r--r-- | cpukit/libmisc/cpuuse/README | 33 |
1 files changed, 3 insertions, 30 deletions
diff --git a/cpukit/libmisc/cpuuse/README b/cpukit/libmisc/cpuuse/README index 20e76f07bc..bd3cc55e34 100644 --- a/cpukit/libmisc/cpuuse/README +++ b/cpukit/libmisc/cpuuse/README @@ -2,40 +2,13 @@ # $Id$ # -This directory contains a stack bounds checker. It provides two +This directory contains a CPU usage reported. It provides two primary features: - + check for stack overflow at each context switch - + provides an educated guess at each task's stack usage - -The stack overflow check at context switch works by looking for -a 16 byte pattern at the logical end of the stack to be corrupted. -The "guesser" assumes that the entire stack was prefilled with a known -pattern and assumes that the pattern is still in place if the memory -has not been used as a stack. - -Both of these can be fooled by pushing large holes onto the stack -and not writing to them... or (much more unlikely) writing the -magic patterns into memory. - -This code has not been extensively tested. It is provided as a tool -for RTEMS users to catch the most common mistake in multitasking -systems ... too little stack space. Suggestions and comments are appreciated. + + provides an educated guess at each task's CPU usage NOTES: -1. Stack usage information is questionable on CPUs which push - large holes on stack. - -2. The stack checker has a tendency to generate a fault when - trying to print the helpful diagnostic message. If it comes - out, congratulations. If not, then the variable Stack_check_Blown_task - contains a pointer to the TCB of the offending task. This - is usually enough to go on. - -FUTURE: +1. CPU usage is "docked" by a clock tick at each context switch. -1. Determine how/if gcc will generate stack probe calls and support that. -2. Get accurate stack usage numbers on i960.. it pushes very large - holes on the stack. |