cvs commit: src/sys/i386/i386 pmap.c

[Jacques Vidrine]

nectar      2003/10/07 05:34:37 PDT

  FreeBSD src repository

  Modified files:        (Branch: RELENG_4)
    sys/i386/i386        pmap.c 
  Log:
  Disable PSE at boot time for Pentium 4 processors.  On many such CPUs,
  data corruption will result otherwise.  It seems that the bug is
  aggravated by recent work related to PAE.
  
  This change was originally based on rev 1.386, but now the test for
  CPU type is correct and the display of the warning is postponed until
  we have initialized the kernel message buffer (e.g. for dmesg).
  
  peter@ believes that only certain revisions of the Pentium 4 processor
  are affected.  However, we are unsure which so we choose to be safe by
  disabling PSE on all Pentium 4s.
  
  The test can be disabled entirely with NO_PSE_HACK.
  
  Approved by:    re
  
  Revision    Changes    Path
  1.250.2.22  +34 -0     src/sys/i386/i386/pmap.c