git: kernel - Adjust tlb invalidation in the x86-64 pmap code

Matthew Dillon dillon at
Fri Nov 18 08:17:06 PST 2011

commit 52bb73bc908f2d4fb004ad3c5c97f4d25402d2c2
Author: Matthew Dillon <dillon at>
Date:   Fri Nov 18 08:10:41 2011 -0800

    kernel - Adjust tlb invalidation in the x86-64 pmap code
    * Use a locked bus cycle instruction to clear pte's in all cases.
    * Remove unnecessary vm_page_hold() when removing a page table page pv.
      The page is still wired so a hold is not needed.
    * Do not issue invalidation interlocks when populating a user pte, the
      invalidations issued when the user pte is removed are sufficient.
      Kernel pte's still appear to need an interlock.  It is unclear why
      (possibly early PG_PS replacement issues).
    * Revamp pmap_enter() to fix a race case which could allow PG_M to get
      lost.  Any protection or wiring change fully removes the pte before
      loading a revised pte.

Summary of changes:
 sys/platform/pc64/x86_64/pmap.c |  182 +++++++++++++++++----------------------
 1 files changed, 78 insertions(+), 104 deletions(-)

DragonFly BSD source repository

More information about the Commits mailing list