From sandiegobiker at gmail.com  Mon Dec  8 18:46:04 2008
From: sandiegobiker at gmail.com (Len Gross)
Date: Mon Dec  8 18:46:10 2008
Subject: Multiple CPU's and interrupt latency / "determinism"
Message-ID: <27cb3ada0812081823t37ef89b1td04eb605795cf3f2@mail.gmail.com>

Is there a way to use multiple CPUs so that the interrupt latency of
the system is bounded and presumably smaller than a single CPU system?
 That is, can I have a process isolated so that for all practical
purposes it is real-time?

My particular issue is needing to be able to transmit network packets
at very precise times.

Thanks in advance.
From alfred at freebsd.org  Sat Dec 27 14:55:37 2008
From: alfred at freebsd.org (Alfred Perlstein)
Date: Sat Dec 27 14:55:43 2008
Subject: (forw) Re: Process stuck in STOP state
Message-ID: <20081227223820.GE18389@elvis.mu.org>

Can someone look at this?  This is pretty weird, it seems
that somehow there's some deadlock with vnode locks, but it
doesn't appear to be due a leaked vnode lock as "show lockednods"
doesn't show any vnodes locks.

The trace should be somewhat easy to figure out but I'm kinda
of stuck..

Any ideas how this could happen?

-Alfred

----- Forwarded message from Lin Jui-Nan Eric <ericlin@tamama.org> -----

From: "Lin Jui-Nan Eric" <ericlin@tamama.org>
To: "Alfred Perlstein" <alfred@freebsd.org>
Cc: stable@freebsd.org
Subject: Re: Process stuck in STOP state
Date: Fri, 26 Dec 2008 12:41:12 +0800
Message-ID: <47713ee10812252041p3b4ba9e8sa92772264bd2ac3b@mail.gmail.com>

Hi,

Full back-trace is located here:
http://aqua.pixnet.tw/~jnlin/textdump/event3/1226/

On Fri, Dec 26, 2008 at 11:34 AM, Lin Jui-Nan Eric <ericlin@tamama.org> wrote:
> Hi,
>
> No, NFS is not working (df hangs, and cd /nfs/vol hangs, too). we have
> run fstat and see some NFS file is opened.
> I will do a full back-trace while this happened again. (It happens
> very frequently....about 10 times/day now)
>
> On Fri, Dec 26, 2008 at 11:26 AM, Alfred Perlstein <alfred@freebsd.org> wrote:
>> * Lin Jui-Nan Eric <ericlin@tamama.org> [081225 02:44] wrote:
>>> Hi,
>>>
>>> We have done a textdump, located here: http://aqua.pixnet.tw/~jnlin/textdump/
>>> Thank you!
>>
>> Is NFS working when this happens?
>>
>> Can you run lsof too?
>>
>> It would be really good to get a backtrace from all processes, there's
>>  a ddb command to do this.
>>
>> -Alfred
>>
>>>
>>> On Wed, Dec 24, 2008 at 11:07 AM, Alfred Perlstein <alfred@freebsd.org> wrote:
>>> > * Lin Jui-Nan Eric <ericlin@tamama.org> [081223 09:17] wrote:
>>> >> > Dear listers,
>>> >> >
>>> >> > Our FreeBSD Server uses NFS to access PHP files on NetApp, then serve
>>> >> > them with apache 2.2 (worker MPM + php fastcgi mode).
>>> >> Sorry. we use -STABLE now.
>>> >>
>>> >> event# uname -a
>>> >> FreeBSD event 7.1-PRERELEASE FreeBSD 7.1-PRERELEASE #1: Thu Dec  4
>>> >> 01:45:42 CST 2008     root@event:/usr/obj/usr/src/sys/KERNEL  amd64
>>> >> _______________________________________________
>>> >> freebsd-stable@freebsd.org mailing list
>>> >> http://lists.freebsd.org/mailman/listinfo/freebsd-stable
>>> >> To unsubscribe, send any mail to "freebsd-stable-unsubscribe@freebsd.org"
>>> >
>>> > It'd be good if you could get to ddb and do a "show all"
>>> > or "threads" and get all threads backtrace to see what's happening.
>>> >
>>> > thank you,
>>> > --
>>> > - Alfred Perlstein
>>> >
>>> _______________________________________________
>>> freebsd-stable@freebsd.org mailing list
>>> http://lists.freebsd.org/mailman/listinfo/freebsd-stable
>>> To unsubscribe, send any mail to "freebsd-stable-unsubscribe@freebsd.org"
>>
>> --
>> - Alfred Perlstein
>>
>

----- End forwarded message -----

-- 
- Alfred Perlstein