mirror of https://gitee.com/openkylin/linux.git
597bc5c00b
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> |
||
|---|---|---|
| .. | ||
| .gitignore | ||
| Makefile | ||
| cacheflush.S | ||
| datapage.S | ||
| gettimeofday.S | ||
| note.S | ||
| sigtramp.S | ||
| vdso64.lds.S | ||
| vdso64_wrapper.S | ||