bytes-consed-between-gcs is locked to 32-bit regardless of machine word size

[David Holz]

On a 64-bit system, setting bytes-consed-between-gcs to 9GB results in a nursery memory usage pattern with a 1GB range.

The setter & reader for bytes-consed-between-gcs in gc.lisp uses (sb!alien:unsigned 32), while the C code is an unsigned long. This prevents 64-bit systems from using >4GB nursery size, which is sometimes desirable. It seems to silently mask the 64-bit number to 32-bit without any warnings or other bugs.

Changing the accessors to use sb!alien:unsigned-long seemed to fix it on our end. The current git browser on SF shows unsigned 32's.

[Nikodemus Siivola (nikodemus)]

Can't use unsigned-long as apparently that's 32 bits on win64. Feh.

commit 3cd198ea8fb1635057038934730624e68b5da012
Author: Nikodemus Siivola <email address hidden>
Date: Sat Nov 19 14:16:47 2011 +0200

    unsigned long -> os_vm_size_t refactoring

     Replace a number of GC related unsigned longs with os_vm_size_t, make it
     available in on the lisp-side as well, and use where appropriate.

     Makes BYTES-CONSED-BETWEEN-GCS and its SETF-version also support large
     nurseries.