StorageTek 6 manual SCP GTRACE Emulation

SCP GTRACE Emulation

The SCP emulates the following MVS GTRACE features:

1.The MVS GTRACE macro is supported, without alteration.

2.A Monitor Call (MC) program interrupt occurs when the GTRACE function is invoked. The SCP program check handler recognizes and handles the Monitor Call as a GTRACE event.

3.Up to 256 bytes of user data may be traced.

4.With most interrupts, the SCP dispatcher does not return to the interrupted task immediately, but dispatches the next task in the priority queue. However, after a monitor call program interrupt the interrupted task IS returned to immediately. If this were not done, program flow would be artificially altered by the act of tracing.

5.The Format Id (FID) parameter is supported. It describes the internal format of the trace record. The valid (decimal) FID ranges are:

1 <= user FID <= 80

81 <= system FID <= 255

Actual FIDs used by the SCP are:

Table 21. FIDs Used by SCP

Decimal	Hex	Char	Meaning
195	x’C3’	c’C’	IUCV event
196	x’C4’	c’D’	Dispatcher event
197	x’C5’	c’E’	External interrupt
201	x’C9’	c’T’	I/O interrupt
212	x’D4’	c’M’	Machine check interrupt
215	x’D7’	c’P’	Program interrupt
217	x’D9’	c’R’	Restart interrupt
226	x’E2’	c’S’	Start I/O
229	x’E5’	c’V’	Supervicor call interrupt
230	x’E6’	c’W’	Return from SVC

The actual FID used by the HSC is passed to the HSC initialization routine (SLSBINIT), and is recorded in the ACS SYSPROF file. The default FID is 23.

6.The Event ID (EID) parameter is supported. It describes the event as a subtype of the Format ID.

It is specified as a 4-digit hexadecimal number, of which the left-most digit is the monitor call class.

372VM/HSC 6.0 System Programmer’s Guide

1st ed., 6/30/04 - 312579601