Paul Mackerras 597bc5c00b powerpc: Improve resolution of VDSO clock_gettime
Currently the clock_gettime implementation in the VDSO produces a
result with microsecond resolution for the cases that are handled
without a system call, i.e. CLOCK_REALTIME and CLOCK_MONOTONIC.  The
nanoseconds field of the result is obtained by computing a
microseconds value and multiplying by 1000.

This changes the code in the VDSO to do the computation for
clock_gettime with nanosecond resolution.  That means that the
resolution of the result will ultimately depend on the timebase
frequency.

Because the timestamp in the VDSO datapage (stamp_xsec, the real time
corresponding to the timebase count in tb_orig_stamp) is in units of
2^-20 seconds, it doesn't have sufficient resolution for computing a
result with nanosecond resolution.  Therefore this adds a copy of
xtime to the VDSO datapage and updates it in update_gtod() along with
the other time-related fields.

Signed-off-by: Paul Mackerras <paulus@samba.org>
2008-11-06 09:49:22 +11:00
..
2008-08-04 13:18:17 +10:00
2008-09-24 16:26:43 -05:00
2008-08-18 21:40:03 +02:00
2008-08-04 13:18:17 +10:00
2008-10-31 16:11:47 +11:00
2008-10-21 15:52:04 +11:00
2008-10-15 11:31:54 +11:00
2008-10-22 22:55:20 -07:00
2008-09-06 19:30:15 +01:00