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From: Colin Percival <cperciva@FreeBSD.org>
Date: Sat, 11 Dec 2010 22:33:33 +0000 (UTC)
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Subject: cvs commit: src/sys/i386/xen clock.c
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cperciva    2010-12-11 22:33:33 UTC

  FreeBSD src repository

  Modified files:
    sys/i386/xen         clock.c 
  Log:
  SVN rev 216385 on 2010-12-11 22:33:33Z by cperciva
  
  Reduce the Xen timecounter from 1GHz to 2^-9 GHz, thereby increasing the
  timecounter period from 2^32 ns (~4.3s) to 2^41 ns (~36m39s).  Some time
  sharing systems can skip clock interrupts for a few seconds when under
  load (e.g., if we've recently used more than our fair share of CPU and
  someone else wants a burst of CPU) and we were losing time in quanta of
  2^32 ns due to timecounter wrapping.
  
  Increasing the timecounter period up to 2^41 ns is definitely overkill,
  but we still have microsecond timecounter precision, and anyone using
  paravirtualized hardware when they need submicrosecond timing is crazy.
  
  Revision  Changes    Path
  1.15      +3 -2      src/sys/i386/xen/clock.c