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Date:   Fri, 7 Sep 2018 10:21:56 +0200 (CEST)
From:   Thomas Gleixner <tglx@linutronix.de>
To:     "Yang, Bin" <bin.yang@intel.com>
cc:     "mingo@kernel.org" <mingo@kernel.org>,
        "hpa@zytor.com" <hpa@zytor.com>,
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        "x86@kernel.org" <x86@kernel.org>,
        "Hansen, Dave" <dave.hansen@intel.com>
Subject: Re: [PATCH v3 4/5] x86/mm: optimize static_protection() by using
 overlap()
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On Fri, 7 Sep 2018, Yang, Bin wrote:
> On Fri, 2018-09-07 at 09:49 +0200, Thomas Gleixner wrote:
> > On Fri, 7 Sep 2018, Yang, Bin wrote:
> > > On Tue, 2018-09-04 at 14:22 +0200, Thomas Gleixner wrote:
> > > 
> > > I just write a test.c to compare the result between overlap() and
> > > original within().
> > 
> > You are right. Your version of doing the overlap exclusive works. I misread
> > the conditions. I still prefer doing inclusive checks because they are way
> > more obvious.
> 
> I am sorry for my poor english. What is "inclusive checks"?

Exlusive:    val >= start && val < end

Inclusive:   val >= start && val <= end

So the difference is that you feed exclusive with:

   end = start + size

and inclusive with

  end = start + size - 1

Thanks,

	tglx