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Date:   Mon, 18 Mar 2019 07:27:12 -0700
From:   "Paul E. McKenney" <paulmck@linux.ibm.com>
To:     Eial Czerwacki <eial@scalemp.com>
Cc:     Tejun Heo <tj@kernel.org>, Barret Rhoden <brho@google.com>,
        Christopher Lameter <cl@linux.com>,
        Dennis Zhou <dennis@kernel.org>, linux-kernel@vger.kernel.org,
        Shai Fultheim <shai@scalemp.com>, Oren Twaig <oren@scalemp.com>
Subject: Re: [PATCH] percpu/module resevation: change resevation size iff
 X86_VSMP is set
Reply-To: paulmck@linux.ibm.com
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On Mon, Mar 18, 2019 at 10:18:48AM +0200, Eial Czerwacki wrote:
> Greetings Paul,
> 
> On 3/15/19 12:19 AM, Paul E. McKenney wrote:
> > On Thu, Mar 14, 2019 at 10:36:19AM -0700, Tejun Heo wrote:
> >> On Wed, Mar 13, 2019 at 04:11:55PM -0700, Paul E. McKenney wrote:
> >>> commit 34f67df09cc0c6bf082a7cfca435373caeeb8d82
> >>> Author: Paul E. McKenney <paulmck@linux.ibm.com>
> >>> Date:   Wed Mar 13 16:06:22 2019 -0700
> >>>
> >>>     srcu: Forbid DEFINE{,_STATIC}_SRCU() from modules
> >>>     
> >>>     Adding DEFINE_SRCU() or DEFINE_STATIC_SRCU() to a loadable module
> >>>     requires that the size of the reserved region be increased, which is
> >>>     not something we want to be doing all that often.  Instead, loadable
> >>>     modules should define an srcu_struct and invoke init_srcu_struct()
> >>>     from their module_init function and cleanup_srcu_struct() from their
> >>>     module_exit function.  Note that modules using call_srcu() will also
> >>>     need to invoke srcu_barrier() from their module_exit function.
> >>>     
> >>>     This commit enforces this advice by refusing to define DEFINE_SRCU()
> >>>     and DEFINE_STATIC_SRCU() within loadable modules.
> >>>     
> >>>     Suggested-by: Barret Rhoden <brho@google.com>
> >>>     Signed-off-by: Paul E. McKenney <paulmck@linux.ibm.com>
> >>
> >> Looks-great-to-me-by: Tejun Heo <tj@kernel.org>
> > 
> > Applied.  ;-)
> > 
> > 							Thanx, Paul
> > 
> >> Thanks. :)
> >>
> >> -- 
> >> tejun
> >>
> > 
> > 
> 
> when can this patch be found in the kernel mainline git repo? I'd like
> to test and see if the patch that started this mail thread still occurs.

Thank you for your interest!

It is a3f5f4fae725 ("srcu: Forbid DEFINE{,_STATIC}_SRCU() from modules")
in my -rcu tree.  If all goes well, I will submit it to the v5.2 merge
window.  I do not expect it to be submitted to -stable.

And -rcu is here:

	git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu.git

							Thanx, Paul