linux-kernel - Re: [RFC PATCH 5/5] x86/entry: Store CPU info on exception entry

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Message-ID: <Yu4wON0MRGH7h5Jv@zn.tnic>
Date:   Sat, 6 Aug 2022 11:11:20 +0200
From:   Borislav Petkov <bp@...en8.de>
To:     Ingo Molnar <mingo@...nel.org>
Cc:     Dave Hansen <dave.hansen@...el.com>, ira.weiny@...el.com,
        Rik van Riel <riel@...riel.com>, x86@...nel.org,
        linux-kernel@...r.kernel.org, kernel-team@...com
Subject: Re: [RFC PATCH 5/5] x86/entry: Store CPU info on exception entry

On Sat, Aug 06, 2022 at 11:01:06AM +0200, Ingo Molnar wrote:
> It's still 2 instructions more than what we had before, while the 
> fault-time CPU number is only needed infrequently AFAICS.

With the amount of logical cores ever increasing and how CPU packages
(nodes, L3 sharing, you name it) get more and more complex topology,
I'd say the 2 insns to show the CPU number in every exception is a good
thing to do.

Arguably, we probably should've even done it already...

-- 
Regards/Gruss,
    Boris.

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