Re: [PATCH] aio: Convert ioctx_table to XArray

From: Matthew Wilcox
Date: Tue Dec 11 2018 - 13:53:16 EST

On Tue, Dec 11, 2018 at 11:46:53AM -0700, Jens Axboe wrote:
> On 12/11/18 11:45 AM, Matthew Wilcox wrote:
> > I think we need the rcu read lock here to prevent ctx from being freed
> > under us by free_ioctx().
> Then that begs the question, how about __xa_load() that is already called
> under RCU read lock?

I've been considering adding it to the API, yes. I was under the
impression that nested rcu_read_lock() calls were not expensive, even