[RFC][CFT] GEOM direct dispatch and fine-grained CAM locking

[Alexander Motin]

On 06.09.2013 11:06, Jeremie Le Hen wrote:
> On Fri, Sep 06, 2013 at 12:46:27AM +0200, Olivier Cochard-Labbé wrote:
>> On Thu, Sep 5, 2013 at 11:38 PM, Alexander Motin <mav at freebsd.org> wrote:
>>> I've found and fixed possible double request completion, that could cause
>>> such symptoms if happened. Updated patch located as usual:
>>> http://people.freebsd.org/~mav/camlock_patches/camlock_20130905.patch
>>>
> With this new one I cannot boot any more (I also updated the source
> tree).  This is a hand transcripted version:
>
> Trying to mount root from zfs:zroot/root []...
> panic: Batch flag already set
> cpuid = 1
> KDB: stack backtrace:
> db_trace_self_wrapper()
> kdb_backtrace()
> vpanic()
> kassert_panic()
> xpt_batch_start()
> ata_interrupt()
> softclock_call_cc()
> softclock()
> ithread_loop()
> fork_exit()
> fork_trampoline()

Thank you for the report. I see my fault. It is probably specific to 
ata(4) driver only. I've workarounded that in new patch version, but 
probably that area needs some rethinking.

http://people.freebsd.org/~mav/camlock_patches/camlock_20130906.patch

-- 
Alexander Motin