Re: [PATCH v4 6/7] blk-mq: fix freeze queue race

From: Christoph Hellwig
Date: Tue Sep 29 2015 - 02:56:06 EST


On Mon, Sep 28, 2015 at 10:48:39AM -0400, Tejun Heo wrote:
> Ah, you're right. I was thinking that percpu_ref_switch_to_percpu()
> being called after blk_mq_freeze_queue_start() would be buggy and thus
> the above can't be enough but that is safe as long as the calls are
> properly synchronized. Hmmm... maybe we should add synchronization to
> those operations from percpu_ref side.

I think that would be very useful, as most users of the code will
have similar issues.
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/