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Date:   Wed, 27 Mar 2019 08:10:12 -0700
From:   "Paul E. McKenney" <paulmck@linux.ibm.com>
To:     "Zhang, Jun" <jun.zhang@intel.com>
Cc:     "He, Bo" <bo.he@intel.com>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
        "stable@vger.kernel.org" <stable@vger.kernel.org>,
        "Xiao, Jin" <jin.xiao@intel.com>,
        "Bai, Jie A" <jie.a.bai@intel.com>
Subject: Re: [PATCH 3.18 132/134] rcu: Do RCU GP kthread self-wakeup from
 softirq and interrupt
Reply-To: paulmck@linux.ibm.com
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Hello, Jun,

Do you see the same hang without the patch?

							Thanx, Paul

On Wed, Mar 27, 2019 at 01:50:57AM +0000, Zhang, Jun wrote:
> Hello，Paul
> 
> I use a new NUC (made in 2017) to test, meet the same hang. System run very slowly.
> 
> But I use my PC (made before 2015), test V3.18.136+ patch for 12 hours, still well.
> 
> Maybe V3.18.y don't support some new devices.
> 
> 
> -----Original Message-----
> From: Paul E. McKenney [mailto:paulmck@linux.ibm.com] 
> Sent: Tuesday, March 26, 2019 23:56
> To: He, Bo <bo.he@intel.com>
> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>; linux-kernel@vger.kernel.org; stable@vger.kernel.org; Zhang, Jun <jun.zhang@intel.com>; Xiao, Jin <jin.xiao@intel.com>; Bai, Jie A <jie.a.bai@intel.com>
> Subject: Re: [PATCH 3.18 132/134] rcu: Do RCU GP kthread self-wakeup from softirq and interrupt
> 
> On Tue, Mar 26, 2019 at 08:43:45AM +0000, He, Bo wrote:
> > Hi, Paul:
> > 	I have tried on my PC and not hit any hang issue with RCU torture test for one hour, the configurations are like:
> > OS: ubuntu 16.04
> > kenrel: 3.18.136 + 3.18 rcu patch
> > CPU:  Intel(R) Xeon(R) CPU E3-1225 V2 @ 3.20GHz
> 
> Sounds good, please proceed!
> 
> 							Thanx, Paul
> 
> > -----Original Message-----
> > From: Paul E. McKenney <paulmck@linux.ibm.com>
> > Sent: Tuesday, March 26, 2019 12:00 AM
> > To: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
> > Cc: He, Bo <bo.he@intel.com>; linux-kernel@vger.kernel.org; 
> > stable@vger.kernel.org; Zhang, Jun <jun.zhang@intel.com>; Xiao, Jin 
> > <jin.xiao@intel.com>; Bai, Jie A <jie.a.bai@intel.com>
> > Subject: Re: [PATCH 3.18 132/134] rcu: Do RCU GP kthread self-wakeup 
> > from softirq and interrupt
> > 
> > On Sat, Mar 23, 2019 at 07:33:15AM +0100, Greg Kroah-Hartman wrote:
> > > On Fri, Mar 22, 2019 at 04:00:17PM +0000, He, Bo wrote:
> > > > Hi, Greg:
> > > > 	Can you hold on the 3.18-stable branch, it seems there are some issue, please see the comments from Paul:
> > > > 
> > > > Comments from Paul:
> > > > I subjected all of the others to light rcutorture testing, which 
> > > > they passed.  This v3.18 patch hung, however.  Trying it again 
> > > > with stock
> > > > v3.18 got the same hang, so I believe we can exonerate the patch and give it a good firm "maybe" on 3.18.
> > > > 
> > > > Worth paying special attention to further test results from 3.18.x, though!
> > > 
> > > Ok, I've dropped this from the 3.18.y queue now, thanks.
> > 
> > Bo, if you know of a "y" for 3.18.y that would likely pass rcutorture testing, please let me know.
> > 
> > 							Thanx, Paul
> > 
>