Date: Wed, 29 Jun 2005 14:21:07 -0400 From: John Baldwin <jhb@FreeBSD.org> To: freebsd-current@freebsd.org Cc: Jens Schweikhardt <schweikh@schweikhardt.net> Subject: Re: Timekeeping hosed by factor 3, high lapic[01] interrupt rates Message-ID: <200506291421.09040.jhb@FreeBSD.org> In-Reply-To: <20050629174243.GA762@schweikhardt.net> References: <20050516113420.GA786@schweikhardt.net> <200506281729.22302.jhb@FreeBSD.org> <20050629174243.GA762@schweikhardt.net>
next in thread | previous in thread | raw e-mail | index | archive | help
On Wednesday 29 June 2005 01:42 pm, Jens Schweikhardt wrote: > John et al, > > # Can you get the same ntpdate output for the kernel without the patch? > > Sure; boot with kern.smp.disabled=1. > > Script started on Wed Jun 29 19:33:39 2005 > # /etc/rc.d/ntpd stop > Stopping ntpd. > # ntpdate 192.53.103.103; sleep 10; ntpdate 192.53.103.103 > 29 Jun 19:34:10 ntpdate[602]: adjust time server 192.53.103.103 offset > -0.393914 sec 29 Jun 19:34:21 ntpdate[604]: adjust time server > 192.53.103.103 offset -0.391510 sec # sysctl > kern.timecounter.hardware=i8254 > kern.timecounter.hardware: TSC -> i8254 > # ntpdate 192.53.103.103; sleep 10; ntpdate 192.53.103.103 > 29 Jun 19:35:09 ntpdate[616]: step time server 192.53.103.103 offset > 7.003573 sec 29 Jun 19:36:02 ntpdate[618]: step time server 192.53.103.103 > offset 42.615163 sec # sysctl kern.timecounter.hardware=TSC > kern.timecounter.hardware: i8254 -> TSC > # ntpdate 192.53.103.103; sleep 10; ntpdate 192.53.103.103 > 29 Jun 19:36:21 ntpdate[620]: step time server 192.53.103.103 offset > 9.605683 sec 29 Jun 19:36:31 ntpdate[622]: adjust time server > 192.53.103.103 offset 0.002316 sec Script done on Wed Jun 29 19:36:53 2005 > > Regards, > > Jens Well, that's certainly weird. I got those types of numbers (~40 secs) when I was using the broken patch. Without any patches at all, my adjustments were -100 seconds, not +40. There probably should be at least some difference between unpatched and patched. For the sake of my sanity, can you please build a GENERIC kernel from scratch without any patches and capture the above output and then apply http://www.FreeBSD.org/~jhb/patches/i8254_lapic.patch and rebuild and capture the same output again? -- John Baldwin <jhb@FreeBSD.org> <>< http://www.FreeBSD.org/~jhb/ "Power Users Use the Power to Serve" = http://www.FreeBSD.org
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?200506291421.09040.jhb>