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To:     Peter Zijlstra <peterz@infradead.org>
Cc:     LKML <linux-kernel@vger.kernel.org>, x86@kernel.org,
        David Woodhouse <dwmw2@infradead.org>,
        Andrew Cooper <andrew.cooper3@citrix.com>,
        Brian Gerst <brgerst@gmail.com>,
        Arjan van de Veen <arjan@linux.intel.com>,
        Paolo Bonzini <pbonzini@redhat.com>,
        Paul McKenney <paulmck@kernel.org>,
        Tom Lendacky <thomas.lendacky@amd.com>,
        Sean Christopherson <seanjc@google.com>,
        Oleksandr Natalenko <oleksandr@natalenko.name>,
        Paul Menzel <pmenzel@molgen.mpg.de>,
        "Guilherme G. Piccoli" <gpiccoli@igalia.com>,
        Piotr Gorski <lucjan.lucjanov@gmail.com>,
        Usama Arif <usama.arif@bytedance.com>,
        Juergen Gross <jgross@suse.com>,
        Boris Ostrovsky <boris.ostrovsky@oracle.com>,
        xen-devel@lists.xenproject.org,
        Russell King <linux@armlinux.org.uk>,
        Arnd Bergmann <arnd@arndb.de>,
        linux-arm-kernel@lists.infradead.org,
        Catalin Marinas <catalin.marinas@arm.com>,
        Will Deacon <will@kernel.org>, Guo Ren <guoren@kernel.org>,
        linux-csky@vger.kernel.org,
        Thomas Bogendoerfer <tsbogend@alpha.franken.de>,
        linux-mips@vger.kernel.org,
        "James E.J. Bottomley" <James.Bottomley@hansenpartnership.com>,
        Helge Deller <deller@gmx.de>, linux-parisc@vger.kernel.org,
        Paul Walmsley <paul.walmsley@sifive.com>,
        Palmer Dabbelt <palmer@dabbelt.com>,
        linux-riscv@lists.infradead.org,
        Mark Rutland <mark.rutland@arm.com>,
        Sabin Rapan <sabrapan@amazon.com>,
        "Michael Kelley (LINUX)" <mikelley@microsoft.com>,
        David Woodhouse <dwmw@amazon.co.uk>
Subject: Re: [patch v3 34/36] x86/smpboot: Implement a bit spinlock to
 protect the realmode stack
In-Reply-To: <20230509131340.GA83892@hirez.programming.kicks-ass.net>
References: <20230508181633.089804905@linutronix.de>
 <20230508185219.123719053@linutronix.de>
 <20230509131340.GA83892@hirez.programming.kicks-ass.net>
Date:   Tue, 09 May 2023 15:47:36 +0200
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On Tue, May 09 2023 at 15:13, Peter Zijlstra wrote:
> On Mon, May 08, 2023 at 09:44:22PM +0200, Thomas Gleixner wrote:
>
> Do we really care about performance here; or should we pick the simpler
> form? Also, 'lock' is a prefix, not an instruction.

Right. KISS is the way to go.