Currently test case "Testing reading when memory can't be reclaimed."
assumes that the allocation section used by row cache upon entering
will require more free memory than there is available (inc. evictable).
However, the reserves used by allocation section are adjusted
dynamically and depend solely on previous events. In other words there
is no guarantee that the reserve would be increased so much that the
allocation will fail.
The problem is solved by adding another allocation that is guaranteed
to be bigger than all evictable and free memory.
Signed-off-by: Paweł Dziepak <pdziepak@scylladb.com>
c4e71bac7f