John Stultz <john.stultz@xxxxxxxxxx> writes: > On Wed, Jan 4, 2017 at 9:24 AM, Vitaly Kuznetsov <vkuznets@xxxxxxxxxx> wrote: >> While do_adjtimex() is available to userspace via adjtimex syscall it is >> not available to modules which may want to implement in-kernel 'NTP >> clients'. Hyper-V hv_utils is going to be the first one. >> >> Signed-off-by: Vitaly Kuznetsov <vkuznets@xxxxxxxxxx> >> --- >> kernel/time/timekeeping.c | 1 + >> 1 file changed, 1 insertion(+) >> >> diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c >> index da233cd..ae4f24f 100644 >> --- a/kernel/time/timekeeping.c >> +++ b/kernel/time/timekeeping.c >> @@ -2312,6 +2312,7 @@ int do_adjtimex(struct timex *txc) >> >> return ret; >> } >> +EXPORT_SYMBOL_GPL(do_adjtimex); > > No real objections to this, although I do want to better understand > the benefits (and drawbacks) of doing the adjtimex in the kernel > driver rather then via userspace, to make sure the need is sane. > Thank you for your comments John, An alternative approach would be to make this module export an interface for userspace and implement a daemon which would do adjtimex syscalls. In theory this could be a part of an NTP client though I don't think that NTP clients will want to accept such 'alternative' way of getting time. -- Vitaly _______________________________________________ devel mailing list devel@xxxxxxxxxxxxxxxxxxxxxx http://driverdev.linuxdriverproject.org/mailman/listinfo/driverdev-devel
