Re: Call for Testers: Convert watchdog spinlock into a sleepable mutex in if_ndis

On 6/7/08, Coleman Kane <cokane_at_freebsd.org> wrote:
> Hi,
>
> I've got another patch to if_ndis and I'd like to know if any NDIS users
> out there can test it for me and give me some feedback. I've converted
> the ndis_spinlock in if_ndis into a normal sleepable mutex, and would
> like to get some testers. The idea here is to eliminate an unnecessary
> "spinning" in the kernel, where it would be preferable to sleep (for CPU
> usage, interactivity, etc...).
>
> You can download it here:
>       *
> http://people.freebsd.org/~cokane/patches/if_ndis-spinlock-to-mtx.patch
>
> --
> Coleman Kane
>

I did not found any stability regressions in my environment with linked patch.

But I noticed   new   LOR (it appears as soon as radio of device is turned on):

lock order reversal:
 1st 0xc401726c ndis0 (network driver) _at_
/usr/local/src/sys/modules/if_ndis/../../dev/if_ndis/if_ndis.c:1648
 2nd 0xc09b3e74 HAL preemption lock (HAL lock) _at_
/usr/local/src/sys/modules/ndis/../../compat/ndis/subr_hal.c:423
KDB: stack backtrace:
db_trace_self_wrapper(c0708534,c3985bcc,c0541a6e,c070adf6,c09b3e74,...)
at db_trace_self_wrapper+0x26
kdb_backtrace(c070adf6,c09b3e74,c09b0a51,c09b0a48,c09b09f8,...) at
kdb_backtrace+0x29
witness_checkorder(c09b3e74,9,c09b09f8,1a7,c04f7364,...) at
witness_checkorder+0x6de
_mtx_lock_flags(c09b3e74,0,c09b09f8,1a7,c457ebd0,...) at _mtx_lock_flags+0xbc
KfRaiseIrql(2,c457ebd0,c3985c48,c09aacdd,c3d45354,...) at KfRaiseIrql+0x63
KfAcquireSpinLock(c3d45354,c094888a,c4017200,c3d6cc40,c4017200,...) at
KfAcquireSpinLock+0x13
IoQueueWorkItem(c457ebd0,c3d6cc40,0,c4017200,c07040ef,...) at
IoQueueWorkItem+0x2d
ndis_tick(c4017200,0,c070699c,166,c077e594,...) at ndis_tick+0x143
softclock(c077e560,0,c0701ca6,4d4,c3cda6ec,...) at softclock+0x24a
ithread_loop(c3cdb2e0,c3985d38,c0701a09,324,c3c99a70,...) at ithread_loop+0x1b5
fork_exit(c04e74f0,c3cdb2e0,c3985d38) at fork_exit+0xb8
fork_trampoline() at fork_trampoline+0x8
--- trap 0, eip = 0, esp = 0xc3985d70, ebp = 0 ---