Fixed performance monitoring on x86_64. There was apparently no code review of the conversion to Mackerel's shift driver in commit ae6c49c8db8a.
Fixed performance monitoring on x86_64. There was apparently no code review
of the conversion to Mackerel's shift driver in commit ae6c49c8db8a.

mslovy/barrelfish,mslovy/barrelfish,utsav2601/cmpe295A,utsav2601/cmpe295A,linusyang/barrelfish,BarrelfishOS/barrelfish,BarrelfishOS/barrelfish,kishoredbn/barrelfish,BarrelfishOS/barrelfish,kishoredbn/barrelfish,8l/barrelfish,mslovy/barrelfish,kishoredbn/barrelfish,kishoredbn/barrelfish,utsav2601/cmpe295A,mslovy/barrelfish,BarrelfishOS/barrelfish,BarrelfishOS/barrelfish,linusyang/barrelfish,BarrelfishOS/barrelfish,BarrelfishOS/barrelfish,utsav2601/cmpe295A,linusyang/barrelfish,utsav2601/cmpe295A,8l/barrelfish,BarrelfishOS/barrelfish,kishoredbn/barrelfish,linusyang/barrelfish,linusyang/barrelfish,8l/barrelfish,utsav2601/cmpe295A,8l/barrelfish,8l/barrelfish,kishoredbn/barrelfish,BarrelfishOS/barrelfish,mslovy/barrelfish,mslovy/barrelfish,8l/barrelfish