In article <[email protected]>, Paul Goyette <[email protected]> wrote: >According to the clockctl(4) man page, operations on system time should >first try the /dev/clockctl device, and only fall-back to the syscall() >if the device is not available: > > ... The system call stubs in C library will use the ioctl(2) on > /dev/clockctl if the special file is present and accessible, or > will revert to the plain super-user-restricted system call if > the special file is not accessible. > >However, looking at the source file for lib/libc/sys/settimeofday.c we >have the following comment which says that we first try the syscall() >and only use the /dev/clockctl mechanism if the syscall() fails: > >int >settimeofday(const struct timeval *tv, const void *tzp) >{ > struct clockctl_settimeofday args; > int rv; > > /* > * try syscal first and attempt to switch to clockctl > * if that fails with EPERM > */ > >Which of these is correct? And which needs to be updated?
Using the syscall is simpler and cheaper, so I think the man page should be updated. christos
