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FreeBSD 4.6R (HZ=250) おけるチューニング結果

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# ./xps2k -s -w 10
/*
 * usleep() accuracy
 *   I expect usleep(1000) sleeps about less than 8msec...
 *   you may add "HZ=250" in kernel configration
 */
 64.876098sec  usleep( 0*1000)
 64.876128sec  usleep( 1*1000) ---> usleep( 0*1000) sleeps 0.0msec
 64.881791sec  usleep( 2*1000) ---> usleep( 1*1000) sleeps 5.6msec  <===ここ
 64.889792sec  usleep( 3*1000) ---> usleep( 2*1000) sleeps 8.0msec
 64.897791sec  usleep( 4*1000) ---> usleep( 3*1000) sleeps 7.9msec
 64.905792sec  usleep( 5*1000) ---> usleep( 4*1000) sleeps 8.0msec
 64.917794sec  usleep( 6*1000) ---> usleep( 5*1000) sleeps 12.0msec
 64.929795sec  usleep( 7*1000) ---> usleep( 6*1000) sleeps 12.0msec
 64.941794sec  usleep(10*1000) ---> usleep( 7*1000) sleeps 11.9msec
 64.957796sec  usleep(15*1000) ---> usleep(10*1000) sleeps 16.0msec
 64.977796sec  usleep(20*1000) ---> usleep(15*1000) sleeps 20.0msec
 65.001799sec  usleep(30*1000) ---> usleep(20*1000) sleeps 24.1msec
 65.037800sec  usleep(40*1000) ---> usleep(30*1000) sleeps 36.0msec
 65.081802sec                  ---> usleep(40*1000) sleeps 44.0msec

/*
 * wait_half() accuracy
 *   wait_loop is 10
 *   30usec < wait_half()+wait_half() < 50usec, but ...
 */
 65.082125sec
 65.082156sec  --> waits 31usec
 65.082178sec  --> waits 22usec  ===> 53usec  <===ここ と
 65.082201sec  --> waits 23usec  ===> 45usec  <===ここ
 65.082223sec  --> waits 22usec  ===> 45usec
 65.082246sec  --> waits 23usec  ===> 45usec

/*
 * current tty statue
 */
  Line Enable
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