[Info-vax] COD inconsistency

[Volker Halle]

> Worth doing?

It's not much work, please try this:

$ ANALYZE/SYS
SDA> SET PROC OPCOM
SDA> exa 00040910;50  ! offset for V8.3, may also work for V8.4
00000000 00000000 00000000 00000000  ................     00000000.00040910
00000001 00000010 00000080 00000000  ................     00000000.00040920
00000000 00000000 00000000 00000000  ................     00000000.00040930
00040948 00040948 00040940 00040940  @... at ...H...H...     00000000.00040940
00000000 00000000 00040950 00040950  P...P...........     00000000.00040950


The first 2 longwords are COD_ALLOCATED and COD_FREE_COUNT. In an idle OPCOM process, those values should be the same.
The 3 longwords starting at VA 40924 are constants and could be used with SDA> SEARCH to find this data, should the P0 addresses be different in V8.4.

The quadwords at 40940 and 40948 are the queue headers of the COD_FREE_QUEUE and COD_BUSY_QUEUE. If the queues are empty, those longwords contain the address of the queue header (as shown above).

I'm starting to believe, that the values shown in your OPCOM message, are not real counts, but the results of local memory corruption in OPCOM P0 space.

Volker.