On Wed, Feb 16, 2000 at 12:23:18PM -0800, Phil Nelson wrote:
> 
> There appears to be some problem with the private mapping.  I'm not
> quite sure what is happening, but I thought I would ask if anyone
> here might have a clue.  The server was running with -mapprivate
> and was shutdown by volutil.  I then wanted to use norton to look
> at it.  So I tried the following.  Note, first -mapprivate use of norton
> couldn't see any volumes.  Then I ran norton with anonymous mapping and
> all volues were listed.  I then reran with -mapprivate and it could then
> see the volumes. 
>
...
> 
> Comments welcome!

What kernel exactly? I am assuming that the initial private mmap fails
to page in the actual underlying data. The anonymous mapping version
reads the data, filling in pages in memory while doing that. When the
file is closed the inode and pages linger around and the second private
mmap finds these pages already there and doesn't need to trigger paging
things in form disk anymore.

It looks to me like a kernel bug.

Jan