Subject: Re: kern/30815: ntpd refclockio broken wrt/ SIGIO
To: None <kern-bug-people@netbsd.org, gnats-admin@netbsd.org,>
From: Frank Kardel <Frank.Kardel@Acrys.COM>
List: netbsd-bugs
Date: 07/25/2005 20:51:02
The following reply was made to PR kern/30815; it has been noted by GNATS.
From: Frank Kardel <Frank.Kardel@Acrys.COM>
To: Christos Zoulas <christos@zoulas.com>
Cc: gnats-bugs@NetBSD.org, kern-bug-people@NetBSD.org,
gnats-admin@NetBSD.org, netbsd-bugs@NetBSD.org
Subject: Re: kern/30815: ntpd refclockio broken wrt/ SIGIO
Date: Mon, 25 Jul 2005 22:34:41 +0200
Christos Zoulas wrote:
>On Jul 23, 1:30pm, kardel@acm.org (kardel@acm.org) wrote:
>-- Subject: kern/30815: ntpd refclockio broken wrt/ SIGIO
>
>| The recent relaxation to allow SIGIO on tty descriptors without
>| requiring TIOCSCTTY is incomplete. Current version 1.9 of
>| usr.sbin/ntp/include/config.h has USE_FSETOWNCTTY commented out.
>| So ntpd doesn't aquire a CTTY. Fact is that currently TTY input
>| does not cause a SIGIO to be delivered in this setup.
>| ntpd pretends to run because of network SIGIOs, but ntpd is
>| unable to actually use a tty refclock as input on a TTY as
>| input is batched in intervals of network caused SIGIOs.
>|
>| So, currently ntpd refclock support is broken.
>
>Does the code set FIOASYNC?
>
>christos
>
>
>
Yep. As you can see in the ktraces in 30815 the only difference id the
TIOCSCTTY call.
The relevant section in libntp/iosignal.c is:
# if defined(TIOCSCTTY) && defined(USE_FSETOWNCTTY)
/*
* there are, however, always exceptions to the rules
* one is, that OSF accepts SETOWN on TTY fd's only, iff
they ar
e
* CTTYs. SunOS and HPUX do not semm to have this
restriction.
* another question is: how can you do multiple SIGIO
from sever
al
* ttys (as they all should be CTTYs), wondering...
*
* kd 95-07-16
*/
if (ioctl(rio->fd, TIOCSCTTY, 0) == -1)
{
msyslog(LOG_ERR, "ioctl(TIOCSCTTY, 0) fails for
clock I/
O: %m");
return 1;
}
# endif /* TIOCSCTTY && USE_FSETOWNCTTY */
if (fcntl(rio->fd, F_SETOWN, getpid()) == -1)
{
msyslog(LOG_ERR, "fcntl(F_SETOWN) fails for
clock I/O: %
m");
return 1;
}
if (fcntl(rio->fd, F_SETFL, FNDELAY|FASYNC) < 0)
{
msyslog(LOG_ERR,
"fcntl(FNDELAY|FASYNC) fails for clock
I/O: %m")
;
return 1;
}
return 0;
}
As you can see the CTTY is a long standing issue (see my comment from
19950716)
and I'd be all too happy if it improves on NetBSD.
I'll give 1.175 a shot - I just saw it coming in.
Frank