82576 + NETMAP + VLAN

Tue Feb 9 12:31:53 UTC 2016

I am Cc-ing Giuseppe Lettieri who has looked at the problem and may
have some comments to share

cheers
luigi

On Mon, Feb 8, 2016 at 9:39 AM, Slawa Olhovchenkov <slw at zxy.spb.ru> wrote:
> On Thu, Feb 04, 2016 at 10:47:34AM -0800, Adrian Chadd wrote:
>
>> .. but if it does, can you enable witness and see what it reports as
>> lock order violations?
>
> last STABLE:
>
> 1. first LOR (with poll, don't cause direct problems now):
>
> lock order reversal:
>  1st 0xfffff800946e6700 vm object (vm object) @ /usr/src/sys/vm/vm_fault.c:363
>  2nd 0xffffffff813e14d8 netmap memory allocator lock (netmap memory allocator lock) @ /usr/src/sys/dev/netmap/netmap_mem2.c:393
> KDB: stack backtrace:
> #0 0xffffffff80970320 at kdb_backtrace+0x60
> #1 0xffffffff809882ce at witness_checkorder+0xc7e
> #2 0xffffffff8091fcbc at __mtx_lock_flags+0x4c
> #3 0xffffffff806784f6 at netmap_mem_ofstophys+0x36
> #4 0xffffffff80676834 at netmap_dev_pager_fault+0x34
> #5 0xffffffff80b81a0f at dev_pager_getpages+0x3f
> #6 0xffffffff80b8cc1e at vm_fault_hold+0x86e
> #7 0xffffffff80b8c367 at vm_fault+0x77
> #8 0xffffffff80d0e2c9 at trap_pfault+0x199
> #9 0xffffffff80d0db47 at trap+0x527
> #10 0xffffffff80cf4ce2 at calltrap+0x8
>
> 2. kqueue issuse (not LOR!)
>
> acquiring duplicate lock of same type: "nm_kn_lock"
>  1st nm_kn_lock @ /usr/src/sys/kern/kern_event.c:2003
>  2nd nm_kn_lock @ /usr/src/sys/kern/kern_event.c:2003
> KDB: stack backtrace:
> #0 0xffffffff80970320 at kdb_backtrace+0x60
> #1 0xffffffff809882ce at witness_checkorder+0xc7e
> #2 0xffffffff8091fcbc at __mtx_lock_flags+0x4c
> #3 0xffffffff808fd899 at knote+0x39
> #4 0xffffffff8067636b at freebsd_selwakeup+0x8b
> #5 0xffffffff80674eb5 at netmap_notify+0x55
> #6 0xffffffff8067ccb6 at netmap_pipe_txsync+0x156
> #7 0xffffffff80674740 at netmap_poll+0x400
> #8 0xffffffff80676b8e at netmap_knrw+0x6e
> #9 0xffffffff808fc57a at kqueue_register+0x64a
> #10 0xffffffff808fcdd4 at kern_kevent_fp+0x144
> #11 0xffffffff808fcc4f at kern_kevent+0x9f
> #12 0xffffffff808fcaea at sys_kevent+0x12a
> #13 0xffffffff80d0e914 at amd64_syscall+0x2d4
> #14 0xffffffff80cf4fcb at Xfast_syscall+0xfb
>
> Do you need anything?
>
>> On 4 February 2016 at 10:47, Adrian Chadd <adrian.chadd at gmail.com> wrote:
>> > I've no time to help with this, I'm sorry :(
>> >
>> >
>> > -a
>> >
>> >
>> > On 4 February 2016 at 05:00, Slawa Olhovchenkov <slw at zxy.spb.ru> wrote:
>> >> On Tue, Feb 02, 2016 at 11:44:47PM +0300, Slawa Olhovchenkov wrote:
>> >>
>> >>> On Thu, Oct 22, 2015 at 11:24:53AM -0700, Luigi Rizzo wrote:
>> >>>
>> >>> > On Thu, Oct 22, 2015 at 11:12 AM, Adrian Chadd <adrian.chadd at gmail.com> wrote:
>> >>> > > On 22 October 2015 at 09:35, Slawa Olhovchenkov <slw at zxy.spb.ru> wrote:
>> >>> > >> On Sun, Oct 18, 2015 at 07:45:52PM -0700, Adrian Chadd wrote:
>> >>> > >>
>> >>> > >>> Heh, file a bug with luigi; it should be defined better inside netmap itself.
>> >>> > >>
>> >>> > >> I am CC: luigi.
>> >>> > >>
>> >>> > >> Next question: do kevent RX/TX sync?
>> >>> > >> In my setup I am need to manual NIOCTXSYNC/NIOCRXSYNC.
>> >>> > >
>> >>> > > Hi,
>> >>> > >
>> >>> > > Nope. kqueue() doesn't do the implicit sync like poll() does; it's
>> >>> > > just the notification path.
>> >>> >
>> >>> > actually not. When the file descriptor is registered there
>> >>> > is an implicit sync, and there is another one when an event
>> >>> > is posted for the file descriptor.
>> >>> >
>> >>> > unless there are bugs, of course.
>> >>>
>> >>> I found strange behaivor:
>> >>>
>> >>> 1. open netmap and register in main thread
>> >>> 2. kevent register in different thread
>> >>> 3. result: got event by kevent but no ring sinc (all head,tail,cur
>> >>> still 0).
>> >>>
>> >>> Is this normal? Or is this bug?
>> >>>
>> >>> open and registering netmap in same thread as kevent resolve this.
>> >>
>> >> Also, kevent+netmap deadlocked for me:
>> >>
>> >>   PID    TID COMM             TDNAME           KSTACK
>> >>  1095 100207 addos            -                mi_switch+0xe1 sleepq_catch_signals+0xab sleepq_timedwait_sig+0x10 _sleep+0x238 kern_nanosleep+0x10e sys_nanosleep+0x51 amd64_syscall+0x40f Xfast_syscall+0xfb
>> >>  1095 100208 addos            worker#0         mi_switch+0xe1 sleepq_catch_signals+0xab sleepq_wait_sig+0xf _sleep+0x27d kern_kevent+0x401 sys_kevent+0x12a amd64_syscall+0x40f Xfast_syscall+0xfb
>> >>  1095 100209 addos            worker#1         mi_switch+0xe1 turnstile_wait+0x42a __mtx_lock_sleep+0x26b knote+0x38 freebsd_selwakeup+0x8b netmap_notify+0x55 netmap_pipe_txsync+0x156 netmap_poll+0x400 netmap_knrw+0x6e kqueue_register+0x799 kern_kevent+0x158 sys_kevent+0x12a amd64_syscall+0x40f Xfast_syscall+0xfb
>> >>  1095 100210 addos            worker#2         mi_switch+0xe1 sleepq_catch_signals+0xab sleepq_wait_sig+0xf _sleep+0x27d kern_kevent+0x401 sys_kevent+0x12a amd64_syscall+0x40f Xfast_syscall+0xfb
>> >>  1095 100211 addos            worker#NOIP      mi_switch+0xe1 sleepq_catch_signals+0xab sleepq_wait_sig+0xf _sleep+0x27d kern_kevent+0x401 sys_kevent+0x12a amd64_syscall+0x40f Xfast_syscall+0xfb
>> >>  1095 100212 addos            balancer         mi_switch+0xe1 turnstile_wait+0x42a __mtx_lock_sleep+0x26b knote+0x38 freebsd_selwakeup+0x8b netmap_notify+0x2a netmap_pipe_rxsync+0x54 netmap_poll+0x774 netmap_knrw+0x6e kern_kevent+0x5cc sys_kevent+0x12a amd64_syscall+0x40f Xfast_syscall+0xfb


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