cvs commit: src/sys/alpha/alpha clock.c src/sys/alpha/include pcpu.h

[John Baldwin]

jhb         2006-03-07 22:12:09 UTC

  FreeBSD src repository

  Modified files:
    sys/alpha/alpha      clock.c 
    sys/alpha/include    pcpu.h 
  Log:
  Use the Alpha PCC as a cpu ticker for process runtime accounting.  This is
  slightly more tricky than on x86 as although the PCC is 64-bits, it is not
  a simple 64-bit counter like the TSC.  Instead, the upper 32-bits have
  PAL-defined behavior and the lower 32-bits run as a free-running 32-bit
  counter.  To handle this, we detect overflows by maintaining a small amount
  of per-cpu state and use this to simulate the upper 32-bits of the counter
  providing a full 64-bit counter to the consumers of cpu_ticks().
  
  Revision  Changes    Path
  1.44      +26 -0     src/sys/alpha/alpha/clock.c
  1.16      +3 -1      src/sys/alpha/include/pcpu.h