linux-kernel - Re: [PATCH] irqchip/gic-v3: do runtime cpu cap check only when necessary

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Message-ID: <20220829035232.GA13376@dell-PowerEdge-T440>
Date:   Mon, 29 Aug 2022 11:52:33 +0800
From:   Puyou Lu <puyou.lu@...il.com>
To:     Marc Zyngier <maz@...nel.org>
Cc:     Thomas Gleixner <tglx@...utronix.de>,
        Robert Richter <rrichter@...ium.com>,
        Catalin Marinas <catalin.marinas@....com>,
        linux-kernel@...r.kernel.org
Subject: Re: [PATCH] irqchip/gic-v3: do runtime cpu cap check only when
 necessary

On Sun, Aug 28, 2022 at 06:11:15PM +0100, Marc Zyngier wrote:
> Well, what you got wrong is that these instructions are stepped over
> two branches when the caps are finalised, and that doesn't appear in
> the disassembly (you need to look at the code that is actually
> executed).
> 
> Now, any optimisation of the sort must be backed by some performance
> numbers. If you can show that this has a meaningful impact on a given
> workload, I'm happy to look into it. But only if you can show that
> data.
> 
> Thanks,
> 
> 	M.
> 
> -- 
> Without deviation from the norm, progress is not possible.

Thank you very much for correcting me, and sorry for wasting your time, I
got it now.