CVS commit: syssrc/sys/arch/arm26/arm26

[Ben Harris <bjh21%netbsd.org@localhost>]

Module Name:    syssrc
Committed By:   bjh21
Date:           Sun Nov 18 15:47:37 UTC 2001

Modified Files:
        syssrc/sys/arch/arm26/arm26: pmap.c

Log Message:
Several changes (sorry!):

Refuse to clear the modified bit on a page if it has a writeable kernel
mapping.  I'm not sure this is the right thing to do, but since further
writes to the page won't set the bit again, it's safer than clearing it,
and makes NFS writes work properly.

Add debugging code for modified-bit emulation, which checksums
allegedly-unmodified pages to see if they're _really_ unmodified.
Disabled by default because it's slow.

In the process, fix a bug in pv_release whereby the modified bit for a
page got cleared when its last mapping was removed.  This seems to finish
the NFS write fixes started by the first change above.


To generate a diff of this commit:
cvs rdiff -r1.34 -r1.35 syssrc/sys/arch/arm26/arm26/pmap.c

Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.