cvs commit: src/sys/kern vfs_subr.c

[Alan Cox]

On Mon, Aug 02, 2004 at 07:11:03PM -0600, Scott Long wrote:
> David E. O'Brien wrote:
> 
> >obrien      2004-08-02 21:52:43 UTC
> >
> >  FreeBSD src repository
> >
> >  Modified files:
> >    sys/kern             vfs_subr.c 
> >  Log:
> >  Put a cap on the auto-tuning of kern.maxvnodes.
> >  
> >  Cap value chosen by:    scottl
> >  
> >  Revision  Changes    Path
> >  1.518     +8 -0      src/sys/kern/vfs_subr.c
> 
> Well, the number that I gave was really only a suggestion and is
> far too low to be useful on in a production environment like
> squid or a mail/imap server.  What we should really be doing is
> scaling based on the size of the kmem_map.  We should also be
> scaling kmem_map based on the size of physical RAM and not capping
> it to such relatively low values like we do right now.  I'm also
> quite afraid of what might happen to something like squid that
> will be exerting both vnode and mbug pressure at the same time.
> 

It does scale with the amount of physical memory.  There is, however,
an architecture-specific cap to account for the KVA size.  This cap
is now too low, particularly, on i386.

In short, VM_KMEM_SIZE_MAX needs to increase on i386.  I just don't
know how large of an increase is safe.  Do you have access to an i386
with 4+ GB of RAM?

Alan