Re: [ntp:questions] How do I validate my PPS clocks?
On 2013-02-26, rama...@gmail.com rama...@gmail.com wrote: On Tuesday, February 26, 2013 10:57:22 AM UTC+10, unruh wrote: handling. And I only saw 1-2 us difference. Why are you getting 12us on the ldisc code? The 11us in my case is how long it takes to get from early in the interrupt code in arch/x86/kernel/irq_32.c to where the time stamp is normally taken for the pps. o127.127.22.0.PPS.0 l5 16 3770.0000.000 0.001 127.127.28.0.SHM.0 l4 16 3770.0000.011 0.001 That is from a new kernel I have had running for around an hour. The .PPS. time stamp is unmodified from the ppsapi and the .SHM. time stamp is taken at the beginning of the interrupt code. Using /proc to export my time stamp and the shm driver to feed it to ntp. Getting the same 11us difference I see with my normal kernel. Normally I use the earlier time stamp because it has less jitter and is affected less by cpu load. Bizzare. 11us is a huge amount of time. What are you using for the ppsapi? pps-ldisk module? ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] How do I validate my PPS clocks?
On 2013-02-26, rama...@gmail.com rama...@gmail.com wrote: On Tuesday, February 26, 2013 10:57:22 AM UTC+10, unruh wrote: handling. And I only saw 1-2 us difference. Why are you getting 12us on the ldisc code? The 11us in my case is how long it takes to get from early in the interrupt code in arch/x86/kernel/irq_32.c to where the time stamp is normally taken for the pps. o127.127.22.0.PPS.0 l5 16 3770.0000.000 0.001 127.127.28.0.SHM.0 l4 16 3770.0000.011 0.001 That is from a new kernel I have had running for around an hour. The .PPS. time stamp is unmodified from the ppsapi and the .SHM. time stamp is taken at the beginning of the interrupt code. Using /proc to export my time stamp and the shm driver to feed it to ntp. Getting the same 11us difference I see with my normal kernel. Normally I use the earlier time stamp because it has less jitter and is affected less by cpu load. Is it possible that some other module is getting the interrupt and servicing it, before your module that is feeding pps gets it? 11us sounds a lot like the kind of time a interrupt service would take. This would mean that every time and interrupt came on your line (serial port I assume) something else was in an interrupt service which means that that interrupt was triggering that other routine-- ie it was trying to service the same interrupt. Either that or the pps-ldisk routine is really really really badly written. It would be worth trying to track this down. ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] How do I validate my PPS clocks?
unruh un...@invalid.ca wrote: Is it possible that some other module is getting the interrupt and servicing it, before your module that is feeding pps gets it? 11us sounds a lot like the kind of time a interrupt service would take. This would mean that every time and interrupt came on your line (serial port I assume) something else was in an interrupt service which means that that interrupt was triggering that other routine-- ie it was trying to service the same interrupt. Either that or the pps-ldisk routine is really really really badly written. It would be worth trying to track this down. Shared IRQ perhaps? If Linux then the output of /proc/interrupts might show if it is shared. rick jones -- Don't anthropomorphize computers. They hate that. - Anonymous these opinions are mine, all mine; HP might not want them anyway... :) feel free to post, OR email to rick.jones2 in hp.com but NOT BOTH... ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
[ntp:questions] Jim Hodges, 6StringStu, Six String Stu, James Stuart Hodges 3490
3490 577 SW Dexter Cir, Apt 201 1442 SW Haygood Loop, Apt 101 Lake City, FL 32025 (386) 438-8968 Local PD: (386) 752-4344 From: 6StringStu hawkinn...@nccray.net Newsgroups: alt.social-security-disability Date: Fri, 2 Apr 2010 01:02:30 -0500 Of the three felonies on my record, 1: Violation of the Mann act (federal kidnapping...) 2nd Felony arrest Homicide 3rd felony arrest assault with intent Lots of misdomeanors. fighting hand to hand stuff.. From: SixStringStu hawkinnc45rem...@hotmail.com Newsgroups: alt.social-security-disability,alt.comp.blind-users,free.UseNet,free.spam,free.spirit Date: Mon, 10 Sep 2012 21:39:02 -0400 My criminal record consists of one count of driving under the influance of alchohol From: 6StringStu hawkinn...@nccray.net Newsgroups: alt.social-security-disability Date: Fri, 2 Apr 2010 01:02:30 -0500 I used to own quite a few firearms. When I awoke from my coma they had been liquidated. Nowadys I have..a 357mag revolver (I'd hate to drop a shell casing when doing that close up action. A 30-06 with a good scope that I can hit a fist sized target at 500 yards... From: SixStringStu hawkinn...@hotmailremove.com Newsgroups: alt.social-security-disability Date: Fri, 19 Aug 2011 08:49:53 -0400 Of the five guys that jummped me, three are rotting corpses, one is walking around with a pronounced limp and no orbs in their sockets and one pisses his pants everytime a car backfires. ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
[ntp:questions] ntpd locks-up on FreeBSD 8.3
When ntpd loads via rc.d at system start-up it just locks-up. It doesn't finish loading what is in the rc.conf or give me a login prompt. I have to control c out of it to regain control of the computer, but that terminates ntpd. Any help would be appreciated. Regards, Ed ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] ntpd locks-up on FreeBSD 8.3
On 2013-02-28, Edward T. Mischanko etm1...@hotmail.com wrote: When ntpd loads via rc.d at system start-up it just locks-up. It doesn't finish loading what is in the rc.conf or give me a login prompt. I have to control c out of it to regain control of the computer, but that terminates ntpd. Any help would be appreciated. Regards, Ed What happens if you try to run it after you have regained control of the computer? Any messages in dmesg or other logs? And what happens if you try to compile a more recent version of ntpd and run that? ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] ntpd locks-up on FreeBSD 8.3
What command-line options are you using? ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] ntpd locks-up on FreeBSD 8.3
If you could do some debugging, running it under FreeBSD's equivalent of strace would probably reveal the problem. On Thu, Feb 28, 2013 at 11:50 AM, Edward T. Mischanko etm1...@hotmail.com wrote: When ntpd loads via rc.d at system start-up it just locks-up. It doesn't finish loading what is in the rc.conf or give me a login prompt. I have to control c out of it to regain control of the computer, but that terminates ntpd. Any help would be appreciated. Regards, Ed ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] ntpd locks-up on FreeBSD 8.3
Edward T. Mischanko wrote: When ntpd loads via rc.d at system start-up it just locks-up. It doesn't finish loading what is in the rc.conf or give me a login prompt. I have to control c out of it to regain control of the computer, but that terminates ntpd. Any help would be appreciated. That sounds like you are running it with some sort of no-detach debugging option. I'd be more worried that ^C works, as init should not have a control TTY and daemons should not do anything that would cause it, or them, to gain one (generally the first open for input of a terminal). ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] How do I validate my PPS clocks?
On 28/02/2013 04:59, rama...@gmail.com wrote: [] The times are with respect to the time stamp taken at the beginning of handle_irq(). 2.7us is to the start of serial8250_interrupt(), 4.5us is to the start of serial8250_handle_irq() and so on. arch/x86/kernel/irq_32.c handle_irq() 0us drivers/tty/serial/8250/8250.c serial8250_interrupt() 2.7us drivers/tty/serial/8250/8250.c serial8250_handle_irq() 4.5us drivers/tty/serial/8250/8250.c serial8250_modem_status() 7.4us drivers/tty/serial/serial_core.c uart_handle_dcd_change() 7.8us include/linux/pps_kernel.h inline pps_get_ts() What processor and what speed is this being run on, please? I'm trying to get a handle on whether this is a recent PC, an Intel Atom, or an old mobile phone! (OK, I do see the X86!). -- Cheers, David Web: http://www.satsignal.eu ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
