What does it mean when a process is HELD but not LOCKED?

Question

pget(9) documents the PGET_HOLD flag to mean

PGET_HOLD If set, the found process will be held and unlocked.

and

For the PGET_HOLD case, it is returned unlocked (but held).

What does it mean for a process to be held but unlocked?

Answer 1

The sys/proc.h describes "holding" a process as holding its U-area in memory. See definition for PHOLD() and PRELE() macros, at http://fxr.watson.org/fxr/source/sys/proc.h#L755.