Table Of Contents - Red Hat ENTERPRISE LINUX 5.4 - SYSTEMTAP LANGUAGE Reference Manual

1. SystemTap overview
1.1. About this guide ........................................................................................................... 1
1.2. Reasons to use SystemTap .......................................................................................... 1
1.3. Event-action language .................................................................................................. 1
1.4. Sample SystemTap scripts ........................................................................................... 1
1.4.1. Basic SystemTap syntax and control structures ................................................... 1
1.4.2. Primes between 0 and 49 .................................................................................. 2
1.4.3. Recursive functions ........................................................................................... 3
1.5. The stap command ...................................................................................................... 3
1.6. Safety and security ...................................................................................................... 4
2. Types of SystemTap scripts
2.1. Probe scripts ................................................................................................................ 7
2.2. Tapset scripts .............................................................................................................. 7
3. Components of a SystemTap script
3.1. Probe definitions .......................................................................................................... 9
3.2. Probe aliases ............................................................................................................... 9
3.2.1. Prologue-style aliases (=) ................................................................................. 10
3.2.2. Epilogue-style aliases (+=) ............................................................................... 10
3.2.3. Probe alias usage ............................................................................................ 11
3.2.4. Unused alias variables ..................................................................................... 11
3.3. Variables .................................................................................................................... 11
3.4. Auxiliary functions ...................................................................................................... 11
3.5. Embedded C .............................................................................................................. 12
3.6. Embedded C functions ............................................................................................... 12
4. Probe points
4.1. General syntax ........................................................................................................... 15
4.1.1. Prefixes ........................................................................................................... 15
4.1.2. Suffixes ........................................................................................................... 15
4.1.3. Wildcarded file names, function names ............................................................. 15
4.1.4. Optional probe points ....................................................................................... 15
4.2. Built-in probe point types (DWARF probes) .................................................................. 16
4.2.1. kernel.function, module().function ...................................................................... 17
4.2.2. kernel.statement, module().statement ................................................................ 18
4.3. DWARF-less probing .................................................................................................. 18
4.4. Marker probes ............................................................................................................ 19
4.5. Timer probes .............................................................................................................. 19
4.6. Return probes ............................................................................................................ 20
4.7. Special probe points ................................................................................................... 21
4.7.1. begin ............................................................................................................... 21
4.7.2. end ................................................................................................................. 21
4.7.3. begin and end probe sequence ........................................................................ 21
4.7.4. never .............................................................................................................. 21
4.8. Probes to monitor performance ................................................................................... 21
4.8.1. $counter .......................................................................................................... 22
4.8.2. read_counter ................................................................................................... 22
5. Language elements
5.1. Identifiers ................................................................................................................... 23
5.2. Data types ................................................................................................................. 23
5.2.1. Literals ............................................................................................................ 23
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