Re: IDE locking problem

From: Benjamin Herrenschmidt (benh_at_kernel.crashing.org)
Date: 08/03/03

  • Next message: Con Kolivas: "[PATCH] O12.2int for interactivity" 
    To: Jens Axboe <axboe@suse.de>
Date:	03 Aug 2003 12:11:54 +0200

    > > would help making sure we don't get a request sneaking in ?
    >
    > Hmm not really, there's still a chance that could happen.

    Not too familiar with BIO here, but we would need some kind of
    "dead" flag to cause a reject of any try to insert a new request
    in the queue, don't you think ?

    Then, IDE could do something like:

     - set dead flag
     - wait for all pending requests to drain (easy: insert a barrier
       in the queue and wait on it, with a hack for the barrier insertion
       to bypass the dead flag... ugh... maybe a blk_terminate_queue()
       doing all that would be helpful ?)
     - unregister blkdev
     - then tear down the queue (leaving the "empty" queue with the dead
       flag set, not just memset(...,0,...), so that any bozo keeping a
       reference to it will be rejected trying to insert request instead
       of trying to tap an uninitalized queue object

    What do you think ?

    Ben.

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  • Next message: Con Kolivas: "[PATCH] O12.2int for interactivity"

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