Hi Slawa, On 9/16/16 9:03 PM, Slawa Olhovchenkov wrote: > On Fri, Sep 16, 2016 at 11:30:53AM -0700, hiren panchasara wrote: > >> On 09/16/16 at 09:18P, Slawa Olhovchenkov wrote: >>> On Thu, Sep 15, 2016 at 12:06:33PM +0300, Slawa Olhovchenkov wrote: >>> >>>> On Thu, Sep 15, 2016 at 11:59:38AM +0300, Konstantin Belousov wrote: >>>> >>>>> On Thu, Sep 15, 2016 at 12:35:04AM +0300, Slawa Olhovchenkov wrote: >>>>>> On Sun, Sep 04, 2016 at 06:46:12PM -0700, hiren panchasara wrote: >>>>>> >>>>>>> On 09/05/16 at 12:57P, Slawa Olhovchenkov wrote: >>>>>>>> I am try using 11.0 on Dual E5-2620 (no X2APIC). >>>>>>>> Under high network load and may be addtional conditional system go to >>>>>>>> unresponsible state -- no reaction to network and console (USB IPMI >>>>>>>> emulation). INVARIANTS give to high overhad. Is this exist some way to >>>>>>>> debug this? >>>>>>> >>>>>>> Can you panic it from console to get to db> to get backtrace and other >>>>>>> info when it goes unresponsive? >>>>>> >>>>>> ipmi console don't respond (chassis power diag don't react) >>>>>> login on sol console stuck on *tcp. >>>>> >>>>> Is 'login' you reference is the ipmi client state, or you mean login(1) >>>>> on the wedged host ? >>>> >>>> on the wedged host >>>> >>>>> If BMC stops responding simultaneously with the host, I would suspect >>>>> the hardware platform issues instead of a software problem. Do you have >>>>> dedicated LAN port for BMC ? >>>> >>>> Yes. >>>> But BMC emulate USB keyboard and this is may be lock inside USB >>>> system. >>>> "ipmi console don't respond" must be read as "ipmi console runnnig and >>>> attached but system don't react to keypress on this console". >>>> at the sime moment system respon to `enter` on ipmi sol console, but >>>> after enter `root` stuck in login in the '*tcp' state (I think this is >>>> NIS related). >>> >>> ~^B don't break to debuger. >>> But I can login to sol console. >> >> You can probably: >> debug.kdb.enter: set to enter the debugger >> >> or force a panic and get vmcore: >> debug.kdb.panic: set to panic the kernel > > I am reset this host. > PMC samples collected and decoded: > > @ CPU_CLK_UNHALTED_CORE [4653445 samples] > > 51.86% [2413083] lock_delay @ /boot/kernel.VSTREAM/kernel > 100.0% [2413083] __rw_wlock_hard > 100.0% [2413083] tcp_tw_2msl_scan > 99.99% [2412958] pfslowtimo > 100.0% [2412958] softclock_call_cc > 100.0% [2412958] softclock > 100.0% [2412958] intr_event_execute_handlers > 100.0% [2412958] ithread_loop > 100.0% [2412958] fork_exit > 00.01% [125] tcp_twstart > 100.0% [125] tcp_do_segment > 100.0% [125] tcp_input > 100.0% [125] ip_input > 100.0% [125] swi_net > 100.0% [125] intr_event_execute_handlers > 100.0% [125] ithread_loop > 100.0% [125] fork_exit
The only write lock tcp_tw_2msl_scan() tries to get is a INP_WLOCK(inp). Thus here, tcp_tw_2msl_scan() seems to be stuck spinning on INP_WLOCK (or pfslowtimo() is going crazy and calls tcp_tw_2msl_scan() at high rate but this will be quite unexpected). Thus my hypothesis is that something is holding the INP_WLOCK and not releasing it, and tcp_tw_2msl_scan() is spinning on it. If you can, could you compile the kernel with below options: options DDB # Support DDB. options DEADLKRES # Enable the deadlock resolver options INVARIANTS # Enable calls of extra sanity checking options INVARIANT_SUPPORT # Extra sanity checks of internal structures, required by INVARIANTS options WITNESS # Enable checks to detect deadlocks and cycles options WITNESS_SKIPSPIN # Don't run witness on spinlocks for speed And once the issue is reproduce, run in ddb run the below commands: show pcpu show allpcpu show locks show alllocks show lockchain show allchains show all trace This is to see if the contention is indeed on the tcp_tw_2msl_scan's INP_WLOCK. -- Julien
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