cvs commit: src/sys/amd64/amd64 prof_machdep.c src/sys/i386/isa prof_machdep.c

[Bruce Evans]

bde         2006-10-29 09:48:44 UTC

  FreeBSD src repository

  Modified files:
    sys/amd64/amd64      prof_machdep.c 
    sys/i386/isa         prof_machdep.c 
  Log:
  Removed some SMP ifdefs so that using the TSC as a cputime clock is
  not completely decided at config time.  Just don't default to using
  the TSC if there are multiple active CPUs.  Also, don't default to
  using the TSC if it is broken.  SMP ifdefs are still used to disallow
  using perfmon since perfmon is always broken if SMP is just configured.
  
  This only helps much for SMP kernels running on 1 CPU.  The overheads
  for using the i8254 cputime clock were a bit too high on 486/33's, and
  now on multi-GHz CPUs they are usually in the 99-99.9% range.  Switching
  from the old default of an i8254 clock to the TSC works poorly because
  the overheads are not recalibrated.
  
  Use the same condition for declaring perfmon stuff as for using it.
  
  Revision  Changes    Path
  1.28      +5 -10     src/sys/amd64/amd64/prof_machdep.c
  1.29      +10 -9     src/sys/i386/isa/prof_machdep.c