linux-kernel - Re: [PATCH 1/3] x86/resctrl: Get max rmid and occupancy scale directly from CPUID instead of cpuinfo

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Date:   Mon, 17 Jun 2019 01:35:02 -0700
From:   Fenghua Yu <fenghua.yu@...el.com>
To:     Borislav Petkov <bp@...en8.de>
Cc:     Thomas Gleixner <tglx@...utronix.de>,
        Ingo Molnar <mingo@...hat.com>, H Peter Anvin <hpa@...or.com>,
        Christopherson Sean J <sean.j.christopherson@...el.com>,
        Paolo Bonzini <pbonzini@...hat.com>,
        Radim Krcmar <rkrcmar@...hat.com>,
        Ravi V Shankar <ravi.v.shankar@...el.com>,
        linux-kernel <linux-kernel@...r.kernel.org>,
        x86 <x86@...nel.org>, Jacob Pan <jacob.jun.pan@...ux.intel.com>,
        Len Brown <lenb@...nel.org>,
        Peter Zijlstra <peterz@...radead.org>,
        Dave Hansen <dave.hansen@...ux.intel.com>,
        Andy Lutomirski <luto@...nel.org>
Subject: Re: [PATCH 1/3] x86/resctrl: Get max rmid and occupancy scale
 directly from CPUID instead of cpuinfo_x86

On Mon, Jun 17, 2019 at 10:30:48AM +0200, Borislav Petkov wrote:
> On Mon, Jun 17, 2019 at 01:09:09AM -0700, Fenghua Yu wrote:
> > I just keep the code a bit uniform around the calling area where
> > a few functions are called. So get_cqm_info() makes the code a bit more
> > readable.
> > 
> >         init_scattered_cpuid_features(c);
> >         init_speculation_control(c);
> > +       get_cqm_info(c);
> > 
> >         /*
> >          * Clear/Set all flags overridden by options, after probe.
> >          * This needs to happen each time we re-probe, which may happen
> >          * several times during CPU initialization.
> >          */
> >         apply_forced_caps(c);
> > }
> > 
> > Maybe not? If the function is not good, I can directly put the code here?
> 
> If you want to have it cleaner, make that a separate patch and say so in
> the commit message. Patches should do one logical thing and not mix up
> different changes which makes review harder.

So in patch 0001, move the code of getting CQM info from before
calling init_scattered_cpuid_features(c) to after calling the function.

Then in patch 0002, carve out the code of getting CQM info into a
helper function get_cqm_info(c) for cleaner code.

Is this OK? Or the patch 0002 is unnecessary?

Thanks.

-Fenghua