Use this command to change or display the system trace options.
Requirements and Restrictions
You can only enter this command from the basic subsystem (BSS).
Format
Notes:
- You can also separate the parameters with a comma (,).
- Alter
- changes the system trace options.
- NO
- turns off the system trace options.
- BLKCHK
- starts block check mode. Block check mode is used to flag certain
coding errors, such as writing beyond the end of a block, passing blocks
chained to other blocks, and using storage that has already been
released. Performance is decreased while running block check
mode.
- BRANCH
- starts tracing the BALR, BASR, BAKR, and BASSM branch instructions.
The target of the branch instructions is displayed in the branch trace table,
not the address of the branch instruction.
- CDEBUG
- enables the C function trace for ISO-C programs compiled using the TEST
option of one of the IBM C/370 family of compilers supported by the TPF
4.1 system.
NOCDEBUG disables the C function trace for ISO-C programs compiled using
the TEST option.
- ENTER
- starts the enter/back trace, which includes ENTxC and BACKC program
statements in the macro trace.
- Note:
- When you start the enter/back trace, the macro trace also starts.
- IDLETMR
- turns on the idle timer. When the TPF systems are idle and running
under the IBM Virtual Machine (VM) system or shared PR/SM, the idle timer
option causes idle TPF systems to use fewer central processing unit (CPU)
cycles than they normally would while idle. By reducing the amount of
CPU cycles consumed by idle TPF systems, the IBM VM system and shared
PR/SM can support additional TPF systems or better service other work
being performed by the IBM VM system or shared PR/SM.
The idle timer option causes TPF systems to use fewer CPU cycles by
decreasing the frequency of CPU timer interrupts on idle I-streams. It
decreases the frequency of CPU timer interupts for a given I-stream only when
that I-stream is idle. When an I-stream is performing work or when the
idle timer option is turned off, CPU timer interrupts occur at their regular
frequency.
When the TPF system is running native or under dedicated PR/SM, the idle
timer option is ignored and CPU timer interrupts occur at their regular
frequency.
- IO
- starts the I/O trace, which traces I/O interrupts and CIO macros
associated with an I/O device.
- MACRO
- starts the macro trace, which traces all the SVC macros associated with an
ECB. Fast-linked macros are not traced.
- Note:
- When you stop the macro trace (NOMACRO), the enter/back trace also
stops.
- REGS
- includes registers in the macro trace. Therefore, you must also
start the macro trace (MACRO).
- Note:
- This change does not take effect until the next initial program load (IPL) is
performed. Enter ZSTRC DISPLAY to display the value of the
REGS parameter for this IPL and for the next IPL.
- STACK
- places up to 68 bytes of the C function stack data in the trace table when
the CDEBUG parameter is active. The information is displayed in the
dump.
If you specify NOSTACK, only the address of the stack area is placed in the
trace table when the CDEBUG parameter is active.
If the CDEBUG parameter is not active, STACK or NOSTACK will not trace any
information.
- STATIC
- places up to 68 bytes of the C function static data in the trace table
when the CDEBUG parameter is active. The information is displayed in
the dump.
If you specify NOSTATIC, only the address of the static area is placed in
the trace table when the CDEBUG parameter is active.
If the CDEBUG parameter is not active, STATIC or NOSTATIC will not trace
any information.
- SYSLOG
- starts tracing the events previously included in macro or I/O traces that
are not associated with an ECB or an I/O device. Therefore, you must
also start the macro trace (MACRO) or the I/O trace (IO) as
appropriate.
- VRLOG
- activates VEQR mode migration aid logging. This generates a SNAPC
dump whenever an ECB-controlled program attempts to access another ECB, or a
block owned by another ECB, in VEQR mode.
- XHOOKS
- enables the C function trace of breakpoints other than program entry
breakpoints and program exit breakpoints for ISO-C programs
compiled using the sub-options of the TEST option of one of the IBM C/370
family of compilers supported by the TPF 4.1 system.
NOXHOOKS disables the C function trace of breakpoints other than
program entry breakpoints and program exit breakpoints
for ISO-C programs compiled using the sub-options of the TEST option of one of
the IBM C/370 family of compilers supported by the TPF 4.1
system.
If the CDEBUG parameter is not active, XHOOKS will not trace any
information.
- Display
- displays the system trace options.
Additional Information
- Online help information is available for this command. To display
the help information, enter one of the following:
ZSTRC HELP
ZSTRC ?
- The system trace options are initially set as follows:
- NOBLKCHK
- BRANCH
- NOCDEBUG
- ENTER
- NOIDLETMR
- IO
- MACRO
- NOREGS
- NOSTACK
- NOSTATIC
- SYSLOG
- VRLOG
- NOXHOOK.
- The enter/back trace traces a subset of the macro trace. Therefore,
the macro trace is turned on when the enter/back trace is turned on.
Also, the enter/back trace is turned off when the macro trace is turned
off.
- All system trace options are processor unique. As a result, each
option can be turned on or off on each processor without affecting the options
specified on other processors. All system trace option settings are
preserved across an initial program load (IPL).
Examples
In the following example, the displayed information shows that the macro,
enter/back, I/O, branch, and C function trace are turned on, and the block
check trace, C function trace STACK trace, C function trace STATIC trace, and
C function trace XHOOKS trace, and the idle timer option are turned
off.
+--------------------------------------------------------------------------------+
|User: ZSTRC DISPLAY |
| |
|System: STRC0007I 08.13.39 SYSTEM TRACE OPTIONS |
| MACRO TRACE ON |
| ENTER/BACK TRACE ON |
| IO TRACE ON |
| SYSTEM LOG ON |
| BRANCH TRACE ON |
| REGS THIS IPL OFF |
| REGS NEXT IPL OFF |
| BLOCK CHECK OFF |
| VEQR MODE LOGGING ON |
| CDEBUG TRACE ON |
| STACK TRACE OFF |
| STATIC TRACE OFF |
| XHOOKS TRACE OFF |
| IDLE TIMER OFF |
+--------------------------------------------------------------------------------+
In the following example, the enter/back, block check, C function trace, C
function trace STACK trace, and C function trace XHOOKS trace, and idle timer
option are turned on; the I/O and C function trace STATIC trace are
turned off.
+--------------------------------------------------------------------------------+
|User: ZSTRC ALTER ENTER NOIO BLKCHK CDEBUG STACK NOSTATIC XHOOKS IDELTMR |
| |
|System: STRC0007I 15.08.41 SYSTEM TRACE OPTIONS |
| MACRO TRACE ON |
| ENTER/BACK TRACE ON |
| IO TRACE OFF |
| SYSTEM LOG OFF |
| BRANCH TRACE OFF |
| REGS THIS IPL OFF |
| REGS NEXT IPL OFF |
| BLOCK CHECK ON |
| VEQR MODE LOGGING OFF |
| CDEBUG TRACE ON |
| STACK TRACE ON |
| STATIC TRACE OFF |
| XHOOKS TRACE ON |
| IDLE TIMER ON |
+--------------------------------------------------------------------------------+
Related Information