2009-01-09 08:06:37

by Jens Axboe

[permalink] [raw]
Subject: Re: [BUG] AS-ioscheduler: kernel panic at as_exit_queue

On Thu, Jan 08 2009, ???? ?? wrote:
>
> Hi Nick & Jens,
>
> I met a Kernel Panic with AS, the panic pc is at as_exit_queue, and panic
> when the function check whether the fifo_list[REQ_SYNC] and
> fifo_list[REQ_ASYNC] are empty or not, it would Panic if the lists are not
> empty.
>
> The k-panic happened when I plugged out my Micro-SD memory card
> from my phone, the log has been attached onto this mail.
>
> I guess there may be some conflicts between AS and Hot-plug
> mechanism, so I read the code of AS code by code to find anything
> suspicious. I find that AS might does not consider that do any operations
> to the fifo_lists when the device driver try to exit its elevator, so there
> is possibility that when device try to exit, the fifo_lists are not empty,
> and happen kernel panic, though the possibility is really really very
> small:).
>
> Unfortunately, I have met such k-panic more than two times, so I
> think I should get your suggestions first, and then try to do some works
> for this problem:) Look forward for your reply:)
>
> My Linux version : 2.6.25

Please try a newer version, I _think_ this was fixed in sd. CC'ing
Pierre, just in case.

--
Jens Axboe


2009-01-12 15:25:27

by Pierre Ossman

[permalink] [raw]
Subject: Re: [BUG] AS-ioscheduler: kernel panic at as_exit_queue

On Fri, 9 Jan 2009 09:05:17 +0100
Jens Axboe <[email protected]> wrote:

>
> Please try a newer version, I _think_ this was fixed in sd. CC'ing
> Pierre, just in case.
>

When it comes to block layer interactions, and hot removal in
particular, I'm still sticking my head in the sand and wishing the
problems away.

Fully understanding that creation of yours has so far proved to require
way more time than I've been able to put into it. :)

Rgds
--
-- Pierre Ossman

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