Re: [patch 1/16] unplugging fix

Andrew Morton
2002-06-02T07:35:20Z

Andrew Morton wrote:
>
> There's a plugging bug in 2.5.19. Once you start pushing several disks
> hard, the new unplug code gets confused and queues are left in plugged
> state, but not on the plug list. They never get unplugged and the
> machine dies mysteriously.
>

This patch didn't fix it. It made it tons better, but I again have a
wedged box. Same symptoms - against IDE this time.

blk_plug_list is empty. queue_flags=0x03. Interestingly,
q->plug_list is non-empty, non-zero, both list members pointing at
a list which isn't either itself or blk_plug_list.

I note that the code isn't taking queues off the plug list when the queue
is destroyed. Guess that doesn't matter - we never destroy a plugged
queue...

This one is killing me.

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