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Date:   Wed, 26 Jun 2019 13:37:25 -0700
From:   Fenghua Yu <fenghua.yu@intel.com>
To:     Thomas Gleixner <tglx@linutronix.de>
Cc:     Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
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Subject: Re: [PATCH v9 13/17] x86/split_lock: Disable split lock detection by
 kernel parameter "nosplit_lock_detect"
Message-ID: <20190626203724.GD245468@romley-ivt3.sc.intel.com>
References: <1560897679-228028-1-git-send-email-fenghua.yu@intel.com>
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On Wed, Jun 26, 2019 at 10:34:52PM +0200, Thomas Gleixner wrote:
> On Tue, 18 Jun 2019, Fenghua Yu wrote:
> >  
> >  static void split_lock_update_msr(void)
> >  {
> > -	/* Enable split lock detection */
> > -	this_cpu_or(msr_test_ctl_cached, MSR_TEST_CTL_SPLIT_LOCK_DETECT);
> > +	if (split_lock_detect_enabled) {
> > +		/* Enable split lock detection */
> > +		this_cpu_or(msr_test_ctl_cached, MSR_TEST_CTL_SPLIT_LOCK_DETECT);
> > +	} else {
> > +		/* Disable split lock detection */
> 
> Could you please comment the non obvious things and not the obvious ones?
> 
> > +		this_cpu_and(msr_test_ctl_cached, ~MSR_TEST_CTL_SPLIT_LOCK_DETECT);
> 
> It's entirely clear that the if (enabled) path enables it or am I missing
> something?

Ok. I will remove the comments.

Thanks.

-Fenghua