$WW,1$One jiffy is one time slice.  $LK,"cnts.jiffies",A="MN:CCntsGlbls"$ returns time slices since boot.

$LK,"SysTimerRead",A="MN:SysTimerRead"$ reads the timer ticks since boot.  It's not as fast as $LK,"GetTSC",A="MN:GetTSC"$.

Use $LK,"JIFFY_FREQ",A="MN:JIFFY_FREQ"$ to convert $LK,"cnts.jiffies",A="MN:CCntsGlbls"$.

Use $LK,"SYS_TIMER_FREQ",A="MN:SYS_TIMER_FREQ"$ to convert $LK,"SysTimerRead",A="MN:SysTimerRead"$.