Re: panic: _mtx_lock_sleep: recursed on non-recursive mutex em0 _at_ /usr/src/sys/dev/e1000/if_lem.c:881

On Thu, Jul 26, 2012 at 09:01:18AM -0700, Garrett Cooper wrote:
> On Thu, Jul 26, 2012 at 8:46 AM, David Wolfskill <david_at_catwhisker.org> wrote:
> > This is at r238795; cut/paste of backtrace:
> >
> > KDB: enter: panic
> > [ thread pid 12 tid 100026 ]
> > Stopped at      kdb_enter+0x3d: movl    $0,kdb_why
> > db> bt
> > Tracing pid 12 tid 100026 td 0xc6755000
> > kdb_enter(c0f93c5f,c0f93c5f,c0f91e21,f08398f0,c1825c80,...) at kdb_enter+0x3d
> > panic(c0f91e21,c66739a0,c0f20db8,371,c6755000,...) at panic+0x1c4
> > _mtx_lock_sleep(c68b8560,c6755000,c0f20db8,c0f20db8,371,...) at _mtx_lock_sleep+0x35e
> > _mtx_lock_flags(c68b8560,0,c0f20db8,371,0,...) at _mtx_lock_flags+0xdb
> > lem_start(c68ba000,0,c0fa806c,d20,2a,...) at lem_start+0x33
> > if_transmit(c68ba000,c93d9000,6,c6755000,c65da588,...) at if_transmit+0x129
> > ether_output(c68ba000,c93d9000,f0839aa4,0,0,...) at ether_output+0x5df
> > arpintr(c93d9000,8,c0f50314,153,0,...) at arpintr+0x108c
> > netisr_dispatch_src(7,0,c93d9000,c93d9000,c68ba000,c93d0806) at netisr_dispatch_src+0xa7
> > netisr_dispatch(7,c93d9000,c93d9000,10,3,...) at netisr_dispatch+0x20
> > ether_demux(c68ba000,c93d9000,3,0,3,...) at ether_demux+0x133
> > ether_nh_input(c93d9000,c8f012c8,644d6000,c9492d00,0,...) at ether_nh_input+0x329
> > netisr_dispatch_src(9,0,c93d9000,e2e,2,1) at netisr_dispatch_src+0xa7
> > netisr_dispatch(9,c93d9000) at netisr_dispatch+0x20
> > ether_input(c68ba000,c93d9000,c0f20db8,e2e,c11454c0,...) at ether_input+0x21
> > lem_intr(c68b6000,8,c0f8e00d,561,0,...) at lem_intr+0x567
> > intr_event_execute_handlers(c11454c0,c6626200,c0f8e00d,561,c6755000,...) at intr_event_execute_handlers+0xc5
> > ithread_loop(c6627730,f0839d08,c0f8dd64,3db,0,...) at ithread_loop+0xe2
> > fork_exit(c0a2dcb0,c6627730,f0839d08) at fork_exit+0x7c
> > fork_trampoline() at fork_trampoline+0x8
> > --- trap 0, eip = 0, esp = 0xf0839d40, ebp = 0 ---
> > db> show locks
> > exclusive sleep mutex em0 (EM TX Lock) r = 0 (0xc68b8560) locked _at_ /usr/src/sys/dev/e1000/if_lem.c:1324
> > exclusive sleep mutex em0 (EM Core Lock) r = 0 (0xc68b854c) locked _at_ /usr/src/sys/dev/e1000/if_lem.c:1302
> > db>
> >
> > I need to head off to a meeting; I can poke at the machine a bit more
> > in a couple of hours or so.
> 
> Probably fallout from Luigi enabling legacy interrupts by default in r238765.

yes. I'll investigate with David then he returns from the meeting,
and either we find a fix or i will backout the change and add a note
in the source about this problem, should people want to look at
it in the future.

cheers
luigi
on the