Date: Wed, 18 Jun 2014 20:38:16 -0700
From: Andi Kleen <ak@linux.intel.com>
To: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Cc: Dave Hansen <dave.hansen@intel.com>, LKML <linux-kernel@vger.kernel.org>,
        Josh Triplett <josh@joshtriplett.org>,
        "Chen, Tim C" <tim.c.chen@intel.com>, Christoph Lameter <cl@linux.com>
Subject: Re: [bisected] pre-3.16 regression on open() scalability
Message-ID: <20140619033816.GQ8178@tassilo.jf.intel.com>
References: <20140613224519.GV4581@linux.vnet.ibm.com>
 <53A0CAE5.9000702@intel.com>
 <20140618001836.GV4669@linux.vnet.ibm.com>
 <53A132D4.60408@intel.com>
 <20140618125831.GB4669@linux.vnet.ibm.com>
 <53A1CE19.7040103@intel.com>
 <20140618203052.GT4669@linux.vnet.ibm.com>
 <20140618235131.GA25946@linux.vnet.ibm.com>
 <20140619014200.GO8178@tassilo.jf.intel.com>
 <20140619021337.GA4669@linux.vnet.ibm.com>
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On Wed, Jun 18, 2014 at 07:13:37PM -0700, Paul E. McKenney wrote:
> On Wed, Jun 18, 2014 at 06:42:00PM -0700, Andi Kleen wrote:
> > 
> > I still think it's totally the wrong direction to pollute so 
> > many fast paths with this obscure debugging check workaround
> > unconditionally.
> 
> OOM prevention should count for something, I would hope.

OOM in what scenario? This is getting bizarre.

If something keeps looping forever in the kernel creating 
RCU callbacks without any real quiescent states it's simply broken.

-Andi
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