lkml.org 
[lkml]   [2018]   [Mar]   [29]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH 8/8] fs/aio: Use rcu_work instead of explicit rcu and work item
On 03/27, Tejun Heo wrote:
>
> On Tue, Mar 27, 2018 at 04:28:48PM +0200, Oleg Nesterov wrote:
> > > flush_*work() guarantees to wait for the completion of the latest
> > > instance of the work item which was visible to the caller. We can't
> > > guarantee that w/o rcu_barrier().
> >
> > And this is what I can't understand.
> >
> > So let me repeat. Could you please describe a use-case which needs flush_rcuwork()
> > with rcu_barrier() ?
>
> So, if you skip that, flush_work() in itself won't wait for PENDING
> bit at all. It'll return right away if the work item is waiting for
> rcu grace period.

Still no use-case... But yes, I forgot this is needed for correctness.

OK, thanks for your patience. But fyi now I hate this interface even more,
exactly because I was technically wrong in this discussion ;)

Oleg.

\
 
 \ /
  Last update: 2018-03-29 18:49    [W:0.077 / U:0.208 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site