Date: Mon, 5 Mar 2012 13:39:18 -0500 From: Arnaud Lacombe <lacombar@gmail.com> To: Attilio Rao <attilio@freebsd.org> Cc: freebsd-stable <freebsd-stable@freebsd.org> Subject: Re: Complete hang on 9.0-RELEASE Message-ID: <CACqU3MXCf4U9OHShR1BwvPOsiP9=5=A4oTZR02qC8weKhU6p6g@mail.gmail.com> In-Reply-To: <CACqU3MVBzkg%2BjzkBNjcXRqTfxZEX0rXs3HwjQN=hLSfSZWGn7g@mail.gmail.com> References: <CACqU3MUefo4mG3GdZnj6kxxFx4H_M3-NLys8pCKptqNU4r_ywA@mail.gmail.com> <CACqU3MVs1mpiQpjE9xC8aFAKxhzbjUgC_6GKWdAkyr8OGJhycw@mail.gmail.com> <CAJ-FndDz6eRamnf7v6kZwwZQp-JaLYUKX6Gx7MYuZGEFNagmfQ@mail.gmail.com> <CACqU3MV-mDHzmnXY3Mzc%2BBnimJSnUTAPk66fh%2Bzzdfgz4OyPFg@mail.gmail.com> <CACqU3MVL14TxJ81rbM-Oq2P8GZCE0hPKzQpb5eJqZ32YdowSjQ@mail.gmail.com> <CACqU3MVko6jKjs98JeS1NqBp%2BFR0YtMqPq570J3dN7BPyFvdkA@mail.gmail.com> <CAJ-FndCtA6F=XzTbYsDD1y3-aXuOSMDobtSuOgdNVwaNU4kY_A@mail.gmail.com> <CACqU3MWdJAp2XqWESUTtvX7CeESm=WEcqcRa0T105Kx95jMXzA@mail.gmail.com> <CAJ-FndBW2=78cEWfvYFDjZ3z_VOs-Gj836eo7pgwmy0UmuaCeA@mail.gmail.com> <CACqU3MVBzkg%2BjzkBNjcXRqTfxZEX0rXs3HwjQN=hLSfSZWGn7g@mail.gmail.com>
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Hi, On Wed, Feb 29, 2012 at 2:31 PM, Arnaud Lacombe <lacombar@gmail.com> wrote: > Hi, > > On Wed, Feb 29, 2012 at 2:22 PM, Attilio Rao <attilio@freebsd.org> wrote: >> 2012/2/29, Arnaud Lacombe <lacombar@gmail.com>: >>> Hi, >>> >>> On Wed, Feb 29, 2012 at 1:44 PM, Attilio Rao <attilio@freebsd.org> wrot= e: >>>> 2012/2/29, Arnaud Lacombe <lacombar@gmail.com>: >>>>> Hi, >>>>> >>>>> On Wed, Feb 29, 2012 at 12:59 PM, Arnaud Lacombe <lacombar@gmail.com> >>>>> wrote: >>>>>> Hi, >>>>>> >>>>>> On Mon, Feb 27, 2012 at 12:48 PM, Arnaud Lacombe <lacombar@gmail.com= > >>>>>> wrote: >>>>>>> Hi, >>>>>>> >>>>>>> On Mon, Feb 27, 2012 at 10:36 AM, Attilio Rao <attilio@freebsd.org> >>>>>>> wrote: >>>>>>>> 2012/2/27, Arnaud Lacombe <lacombar@gmail.com>: >>>>>>>>> Hi, >>>>>>>>> >>>>>>>>> On Tue, Feb 14, 2012 at 11:41 AM, Arnaud Lacombe <lacombar@gmail.= com> >>>>>>>>> wrote: >>>>>>>>>> Hi folks, >>>>>>>>>> >>>>>>>>>> For the records, I was running some tests yesterday on top of a >>>>>>>>>> 9.0-RELEASE, amd64, kernel when the box hanged. At the time of t= he >>>>>>>>>> hang, the box was running a process with about 2800 threads with >>>>>>>>>> heavy >>>>>>>>>> IPC between 1400 writers and 1400 readers. The box was in single >>>>>>>>>> user >>>>>>>>>> mode (/bin/sh coming from FreeBSD 7.4-STABLE). Here is the begin= ning >>>>>>>>>> of the dmesg: >>>>>>>>>> >>>>>>>>> This happened a second time, now with FreeBSD 8.2-RELEASE. Comple= te >>>>>>>>> machine hang. The machine was running about 4000 threads in a sin= gle >>>>>>>>> process, all the other condition are the same. >>>>>>>> >>>>>>>> Arnaud, >>>>>>>> can you please break in your kernel via KDB, collect the following >>>>>>>> informations from the DDB prompt: >>>>>>>> - ps >>>>>>>> - alltrace >>>>>>>> - show allpcpu >>>>>>>> - possibly get a coredump with 'call doadump' >>>>>>>> >>>>>>> Will do, but I'll need to rebuild a kernel to include DDB. >>>>>>> >>>>>>>> and in the end provide all those along with kernel binary and poss= ibly >>>>>>>> sources somewhere? >>>>>>>> >>>>>>> I'll be testing a bare `release/8.2.0' with the following patch: >>>>>>> >>>>>>> diff --git a/sys/amd64/conf/GENERIC b/sys/amd64/conf/GENERIC >>>>>>> index c3e0095..7bd997f 100644 >>>>>>> --- a/sys/amd64/conf/GENERIC >>>>>>> +++ b/sys/amd64/conf/GENERIC >>>>>>> @@ -79,6 +79,10 @@ options =A0 =A0 =A0INCLUDE_CONFIG_FILE =A0 =A0 #= Include this >>>>>>> file in kernel >>>>>>> >>>>>>> =A0options =A0 =A0 =A0 =A0KDB =A0 =A0 =A0 =A0 =A0 # Kernel debugger= related code >>>>>>> =A0options =A0 =A0 =A0 =A0KDB_TRACE =A0 =A0 # Print a stack trace f= or a panic >>>>>>> +options =A0 =A0 =A0 =A0DDB >>>>>>> +options =A0 =A0 =A0 =A0BREAK_TO_DEBUGGER >>>>>>> +options =A0 =A0 =A0 =A0ALT_BREAK_TO_DEBUGGER >>>>>>> >>>>>>> =A0# Make an SMP-capable kernel by default >>>>>>> =A0options =A0 =A0 =A0 =A0SMP =A0 =A0 =A0 =A0 =A0 # Symmetric Multi= Processor Kernel >>>>>>> >>>>>> ok, it happened again after 2 days, the process was running about 32= 00 >>>>>> threads. I'm trying to break into DDB and let you know, I'm not that >>>>>> successful for now... >>>>>> >>>>> No luck. None of BREAK or ALT_BREAK are responding. I will not touch >>>>> the system in the next few hours if you want me to test something on >>>>> it. In the event of 8.2-RELEASE or 9.0-RELEASE are =A0not meant to wo= rk >>>>> reliably on top of a 7.4-RELEASE userland, I will re-setup the test t= o >>>>> occurs on a clean 9.0-RELEASE system and re-try. >>>> >>>> We allow to break KBI when new releases happens, thus this may cause a >>>> breakage for you, even if a deadlock is really not something you want. >>>> >>>> Can you try enabling SW_WATCHDOG, DEADLKRES and possibly arm your ichw= d? >>>> if the breakage involves clocks or interrupt sources there are still >>>> chances they will be able to catch it though. >>>> >>>> However, it doesn't seem you are setup with a proper serial console? >>> The serial console is working definitively fine. I can break into DDB >>> at will when the test is running. I did not test with ALT_BREAK >>> per-se, but BREAK does work. >> >> So if you try to break in DDB via serial break it doesn't work? >> That is definitively very bad... >> > just to be sure, I rebooted the system and I could break into DDB at > the first attempt with ALT_BREAK, BREAK was a bit more reluctant but > worked too. So yes, this does not taste good :/ > >> Can you try with the options I mentioned earlier and see if something ch= anges? >> > will do, but I will first attempt to reproduce this on 9.0-RELEASE. > 9.0-RELEASE (kernel + userland) hanged today while running 2000 threads. Next step is to reproduce it with a watchdog+textdump enabled kernel. - Arnaud
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