port-amd64/43438: x86 module map size is limited

[mrg%eterna.com.au@localhost]

>Number:         43438
>Category:       port-amd64
>Synopsis:       x86 module map size is limited
>Confidential:   no
>Severity:       serious
>Priority:       high
>Responsible:    port-amd64-maintainer
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Wed Jun 09 02:55:00 +0000 2010
>Originator:     matthew green
>Release:        NetBSD 5.99.30
>Organization:
people's front against (bozotic) www (softwar foundation)
>Environment:
>Description:

        trying to load the "solaris" and "zfs" kmodules into an amd64
        GENERIC kernel results in ENOMEM being returned by the zfs load
        attempt.  i tracked this down to the x86 module_map being 
        sized at 20MB - size of kernel + rodata.  in my case, the module
        map was only left about 3MB or space, and it could not satisfy
        the modload attempts.

>How-To-Repeat:

        boot large amd64 kernel (GENERIC + debugging seems sufficient,
        plus *VERBOSE too) and try to modload zfs.

>Fix:

        i assume that there is some x86 specific setup that limits this
        size to 20MB but i'm not sure what the fix is.

        i worked around the issue by removing about 100 drivers i wasn't
        using from my kernel and freeing up enough space in the module map.