Re: [PATCH] NVMe: do not touch sq door bell if nvmeq has been suspended
From: Keith Busch
Date: Mon Feb 08 2016 - 10:01:38 EST
On Sat, Feb 06, 2016 at 02:32:24PM +0000, Wenbo Wang wrote:
> Keith,
>
> Is the following solution OK?
> synchronize_rcu guarantee that no queue_rq is running concurrently with device disable code. Together with your another patch (adding blk_sync_queue), both sync/async path shall be handled correctly.
>
> Do you think synchronize_rcu shall be added to blk_sync_queue?
I was nearly going to suggest the same last week, but it feels wrong since
no one takes rcu_read_lock in the path we're trying to sychronoize. Is
this safe if the task is interrupted?