Subject: Re: CVS commit: syssrc/sys/uvm
To: Chuck Silvers <>
From: Jason R Thorpe <>
List: tech-kern
Date: 12/31/2001 14:54:26
On Tue, Jan 01, 2002 at 12:34:41AM +0200, Chuck Silvers wrote:

 > this change has the effect of causing MAP_PRIVATE mappings to be
 > copied to anonymous memory when they are mlock()d, so that uvm_fault()
 > doesn't need to copy these pages later when called from ptrace(), thus
 > avoiding the call to pmap_page_protect() and the panic that results
 > from this when the mlock()d region is unlocked or freed.  note that
 > this change doesn't help the case where the wired mapping is MAP_SHARED.

This is Bad.  Running ntpd is now going to cause the entire libc to
be wired down into anonymous memory without any hope of sharing it
with other libc-using processes.  This is a real screw for low-memory

        -- Jason R. Thorpe <>