calling procedures is slow and consumes extra much memory against calling function

Hi

I try to use procedures in Orafce package, and I did some easy performance
tests. I found some hard problems:

1. test case

create or replace procedure p1(inout r int, inout v int) as $$
begin v := random() * r; end
$$ language plpgsql;

This command requires

do $$
declare r int default 100; x int;
begin
for i in 1..300000 loop
call p1(r, x);
end loop;
end;
$$;

about 2.2GB RAM and 10 sec.

When I rewrite same to functions then

create or replace function p1func2(inout r int, inout v int) as $$
begin v := random() * r; end
$$ language plpgsql;

do $$
declare r int default 100; x int; re record;
begin
for i in 1..300000 loop
re := p1func2(r, x);
end loop;
end;
$$;

Then execution is about 1 sec, and memory requirements are +/- zero.

Minimally it looks so CALL statements has a memory issue.

Regards

Pavel