cvs commit: src/sys/vm vm_map.c

Peter Wemm peter at
Tue Jul 20 17:29:21 PDT 2004

peter       2004-07-21 00:29:21 UTC

  FreeBSD src repository

  Modified files:
    sys/vm               vm_map.c 
  Move the initialization and teardown of pmaps to the vmspace zone's
  init and fini handlers.  Our vm system removes all userland mappings at
  exit prior to calling pmap_release.  It just so happens that we might
  as well reuse the pmap for the next process since the userland slate
  has already been wiped clean.
  However.  There is a functional benefit to this as well.  For platforms
  that share userland and kernel context in the same pmap, it means that
  the kernel portion of a pmap remains valid after the vmspace has been
  freed (process exit) and while it is in uma's cache.  This is significant
  for i386 SMP systems with kernel context borrowing because it avoids
  a LOT of IPIs from the pmap_lazyfix() cleanup in the usual case.
  Tested on:  amd64, i386, sparc64, alpha
  Glanced at by:  alc
  Revision  Changes    Path
  1.343     +2 -3      src/sys/vm/vm_map.c

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