get-maximum-allocated-in-generation-2-after-gc returns the maximum bytes used by live objects in generation 2 immediately after any of the preceding GCs of generation 2 since the previous "reset" (a call to
get-maximum-allocated-in-generation-2-after-gc with reset-p non-nil). It also returns the number of GCs of generation 2 since the previous reset.
other-size-in-bytes is the maximum size of live objects in Other segments (that is not Cons, Large or Static) immediately after any of these GCs, and cons-size-in-byte is the maximum size of live conses.
The values of other-size-in-bytes and cons-size-in-byte match the values that would have been reported for generation 2 by room, if it had been called immediately after a GC of generation 2.
The purpose of
get-maximum-allocated-in-generation-2-after-gc is to give useful information for controlling generation 2, for example to decide what values to use in set-expected-allocation-in-generation-2-after-gc. This function is also useful for just counting the number of GCs of generation 2.
LispWorks User Guide and Reference Manual - 20 Sep 2017