Re: [Xen-devel] [PATCH] blkfront: Move blkif_interrupt into a tasklet.

[Jeremy Fitzhardinge <jeremy@xxxxxxxx>]

 On 09/08/2010 12:21 PM, Daniel Stodden wrote:
> On Tue, 2010-09-07 at 22:03 -0400, Jeremy Fitzhardinge wrote:
>> On 09/03/2010 09:08 AM, Daniel Stodden wrote:
>>> We clearly spin_lock_irqsave all through the blkif_do_interrupt frame.
>>>
>>> It follows that something underneath quite unconditionally chose to
>>> reenable them again (?)
>>>
>>> Either: Can you add a bunch of similar WARN_ONs along that path?
>>>
>>> Or: This lock is quite coarse-grained. The lock only matters for queue
>>> access, and we know irqs are reenabled, so no need for flags. In fact we
>>> only need to spin_lock_irq around the __blk_end_ calls and
>>> kick_pending_.
>>>
>>> But I don't immediately see what's to blame, so I'd be curious.
>> It looks like __blk_end_request_all(req, error); (line 743) is returning
>> with interrupts enabled sometimes (not consistently).  I had a quick
>> look through the code, but I couldn't see where it touches the interrupt
>> state at all.
> Oha. Was this found on 2.6.32 or later?

Yeah, xen/next-2.6.32.

    J

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