Does your new VM deal with the unification of the buffer cache?
-Brian

On Nov 13,  9:32am, Chuck Cranor wrote:
} Subject: Re:  vm_fault in pmap_changebit()
} >Thanks for the explanation :) Ah well... I don't know enough to debug this
} >problem... Might it be somehow related to the "lockmgr: locking against
} >myself" panics? I haven't been getting those anymore, but I'm now getting
} >these vm_faults.
} 
} it isn't directly related to that, but there could be an indirect
} relationship.  i think it might be a bit harder to debug this because 
} the user's page table pages are part of user VM and are added by 
} faulting them in using the general VM code.  one thing you might do
} is keep a list of all active pmaps on the system and then when you
} get the error see if the pmap that is in the bad pv entry is on
} that list or not.   then you would better know if the problem was a 
} stale pv_entry or a missing page table page.
} 
} 
} >Cool... are there are there any plans to replace the current VM system
} >with yours?
} 
} it is being looked at.  basically, i have made the code available
} and structured the code in such a way that both the old VM system 
} and my VM system can live in a kernel source tree at the at the 
} same time (thus making the choice of VM system a compile time option
} since i can't see just replacing the old VM without transition period).
} given my current workload (and my need to graduate) that's about all 
} i have time to do right now.
} 
} 
} the status of my current code is that does everything the -current code 
} does with the exception of:
}  [1] async pageout to swap -- it does sync pageout, the async code
}         is written but has not been debugged.
}  [2] SYSV shared memory
}  [3] swapping (i.e. making the u-area pageout to swap)
}  [4] libkvm programs don't work (since i've changed all the internal
}         VM data structures)
} 
} [2] and [3] require a new pager for vm_objects backed by anonymous
} memory to be written (something i have a draft design for but am
} not working on now).   currently anonymous memory is only handled
} through "anon" structures (sort of as described in the SunOS VM 
} paper).  note that there are no vm_object shadow/copy chains in my 
} code (and thus no "object collapse" code to cause headaches like 
} the lockmgr panic problem).
} 
} the code runs on sparc and i386 (use it all the time on my home
} i386 workstation).   the only thing preventing it from running on 
} other ports is that i rewrote MACHINE_NONCONTIG support (yielding
} MACHINE_NEW_NONCONTIG -- a.k.a. MNN) and the other ports haven't 
} been converted to MNN yet (MNN run with either VM system, but my 
} VM system currently requires it).
} 
} chuck
>-- End of excerpt from Chuck Cranor