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From:   Uros Bizjak <ubizjak@gmail.com>
Date:   Tue, 10 Oct 2023 06:39:11 +0200
Message-ID: <CAFULd4badg6edcqk_F2zO++6pFVUrshN8Agf1+Lz90G0_J_-Hg@mail.gmail.com>
Subject: Re: [PATCH tip] x86/percpu: Use C for arch_raw_cpu_ptr()
To:     x86@kernel.org, linux-kernel@vger.kernel.org
Cc:     Nadav Amit <namit@vmware.com>, Andy Lutomirski <luto@kernel.org>,
        Brian Gerst <brgerst@gmail.com>,
        Denys Vlasenko <dvlasenk@redhat.com>,
        "H . Peter Anvin" <hpa@zytor.com>,
        Linus Torvalds <torvalds@linux-foundation.org>,
        Peter Zijlstra <peterz@infradead.org>,
        Thomas Gleixner <tglx@linutronix.de>,
        Josh Poimboeuf <jpoimboe@redhat.com>
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On Mon, Oct 9, 2023 at 10:31=E2=80=AFPM Uros Bizjak <ubizjak@gmail.com> wro=
te:
>
> Implementing arch_raw_cpu_ptr() in C, allows the compiler to perform
> better optimizations, such as setting an appropriate base to compute
> the address instead of an add instruction.

Oops, please disregard this patch. It is a previous version, and now
will fail compilation with KASAN. The new arch_raw_cpu_ptr should
depend on CONFIG_USE_X86_SEG_SUPPORT, not CONFIG_CC_HAS_NAMED_AS.

I will send a v2 after some more testing.

Uros.