Date: Thu, 19 Jan 2012 21:46:24 +0200 From: Alexander Motin <mav@FreeBSD.org> To: Ian Lepore <freebsd@damnhippie.dyndns.org> Cc: freebsd-stable@freebsd.org Subject: Re: Strange 'hangs' with RELENG_9 Message-ID: <4F187310.7020806@FreeBSD.org> In-Reply-To: <1326999941.21604.63.camel@revolution.hippie.lan> References: <4F181FE7.30904@karolyi.hu> <4F182516.3020506@gmail.com> <4F182FB3.7050405@karolyi.hu> <4F183008.9040603@karolyi.hu> <CAFHbX1%2B7N4y1n%2B4mxmyo%2BExDtY4eOdzm7-VJxYb__Q6BRjcgCg@mail.gmail.com> <4F1835ED.3050609@karolyi.hu> <4F1836E1.1080105@karolyi.hu> <4F1848BF.2050900@karolyi.hu> <CAPjTQNGE6nAeiY=0mHr5TLv14Hqb2T_TeWx718bnvCefFwgpQA@mail.gmail.com> <4F184F8F.4040708@FreeBSD.org> <1326999941.21604.63.camel@revolution.hippie.lan>
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On 01/19/12 21:05, Ian Lepore wrote: > On Thu, 2012-01-19 at 19:14 +0200, Alexander Motin wrote: >> On 19.01.2012 18:51, Oliver Pinter wrote: >>> CC: Alexander Motin >>> >>> On 1/19/12, László KÁROLYI<laszlo@karolyi.hu> wrote: >>>> László KÁROLYI wrote: >>>>> Ok, couldn't get it through... So here is it, uploaded: >>>>> >>>>> http://www.freeimagehosting.net/s836i >>>> Another screenshot here: >>>> >>>> http://www.freeimagehosting.net/xv26d >> >> I am not sure how freezes that could be fixed with key press could be >> related to panics around storage. I would try to go two different ways: >> - for panics, if dumping is not possible, I would try to resolve >> address of the "instruction pointer" from both messages with `addr2line >> -e /path/to/kernel address`. >> - for freezes I would try to look on eventtimers(4) subsystem: check >> what timer is used, try to switch to different one, try to switch into >> periodic mode. >> >> Since cause of siis timeouts in SATA2 mode is also unclear, I can't also >> exclude that it may be somehow related. > > The new eventtimers was also the first thing that came to my mind, but I > couldn't quickly find the right way to boot with a different timer. > > I saw in the eventtimers(7) manpage that there's a sysctl to change the > timer, but when I used it the system timing went completely wonky (ntpd > reported it was off by many seconds, a few seconds after I changed it). > When I just tried it again the system locked up and had to be power > cycled. (I'm trying this on old hardware where my only choices are > i8254 and RTC, and changing to RTC apparently doesn't work well.) So I > didn't want to recommend it to someone else. :) That's strange. On all systems I have, I can safely set any event timer in any way. Though for better precision it is better to set them using loader tunable. > For both eventtimers and timecounters, I think it'd be nice if a tunable > or hint could let the user override the quality number. But maybe > there's already some better way of influencing the choices the kernel > makes? kern.eventtimer.timer is both sysctl and loader tunable. You can set it anywhere you want. Also for most enevt timers there are documented tunables to disable them, Also, as I've already said, you may try to switch to old periodic mode by setting kern.eventtimer.periodic. On your old system with just i8254 and RTC it is enabled always automatically. -- Alexander Motin
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