Re: [PATCH 4.14 21/72] locking/qspinlock: Ensure node is initialised before updating prev->next

From: Sudip Mukherjee
Date: Thu Dec 20 2018 - 14:20:44 EST


On Thu, Dec 20, 2018 at 3:41 PM Greg Kroah-Hartman
<gregkh@xxxxxxxxxxxxxxxxxxx> wrote:
>
> On Thu, Dec 20, 2018 at 12:19:04PM +0000, Sudip Mukherjee wrote:
> > Hi Greg,
> >
> > On Thu, Dec 20, 2018 at 9:27 AM Greg Kroah-Hartman
> > <gregkh@xxxxxxxxxxxxxxxxxxx> wrote:
> > >
> > > 4.14-stable review patch. If anyone has any objections, please let me know.
> > >
> > > ------------------
> > >
> > > commit 95bcade33a8af38755c9b0636e36a36ad3789fe6 upstream.
> >
> > It seems 9d4646d14d51 ("locking/qspinlock: Elide back-to-back RELEASE
> > operations with smp_wmb()") is improving the fix. Is it worth to take
> > this also?
>
> If someone could test that this really does help things out, I would be
> glad to take it :)

I can test if Will shows me how to test the improvement, but it might
be easier for him to test than showing me :)


--
Regards
Sudip