Patch to previous changeset. An RSS shrinkage of 1024th of total RSS isn't good enough.  When there is a lot of memory available, this can well be more than the amount by which RSS shrinks, so that our cleanup never triggers.  Instead, trigger on a shrinkage of a limited number of pages.
Patch to previous changeset.
An RSS shrinkage of 1024th of total RSS isn't good enough.  When there
is a lot of memory available, this can well be more than the amount by
which RSS shrinks, so that our cleanup never triggers.  Instead,
trigger on a shrinkage of a limited number of pages.

zyzyis/monetdb,zyzyis/monetdb,zyzyis/monetdb,zyzyis/monetdb,zyzyis/monetdb,zyzyis/monetdb,zyzyis/monetdb,zyzyis/monetdb,zyzyis/monetdb,zyzyis/monetdb