From: Dave Hansen <dave.hansen@intel.com>
To: "Ahmed S. Darwish" <darwi@linutronix.de>,
Borislav Petkov <bp@alien8.de>, Ingo Molnar <mingo@redhat.com>,
Dave Hansen <dave.hansen@linux.intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>,
Andrew Cooper <andrew.cooper3@citrix.com>,
"H. Peter Anvin" <hpa@zytor.com>,
x86@kernel.org, John Ogness <john.ogness@linutronix.de>,
x86-cpuid@lists.linux.dev, LKML <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH v1 07/12] tools/x86/kcpuid: Add rudimentary CPU vendor detection
Date: Thu, 6 Mar 2025 14:00:52 -0800 [thread overview]
Message-ID: <0ada12f8-4fdb-4dad-90f7-b044993e829c@intel.com> (raw)
In-Reply-To: <20250306205000.227399-8-darwi@linutronix.de>
On 3/6/25 12:49, Ahmed S. Darwish wrote:
> +/*
> + * Leaf 0x0 EDX output, CPU vendor ID string bytes 4 - 7.
> + */
> +enum {
> + EDX_INTEL = fourcc('i', 'n', 'e', 'I'), /* Genu_ineI_ntel */
> + EDX_AMD = fourcc('e', 'n', 't', 'i'), /* Auth_enti_cAMD */
> + EDX_HYGON = fourcc('n', 'G', 'e', 'n'), /* Hygo_nGen_uine */
> + EDX_TRANSMETA = fourcc('i', 'n', 'e', 'T'), /* Genu_ineT_Mx86 */
> + EDX_CENTAUR = fourcc('a', 'u', 'r', 'H'), /* Cent_aurH_auls */
> + EDX_ZHAOXIN = fourcc('a', 'n', 'g', 'h'), /* Sh_angh_ai */
> +};
So, this is cute and all. But isn't it a _wee_ bit too clever for its
own good?
Why not just have a dumb array:
{ INTEL, "GenuineIntel" },
{ AMD, "AuthenticAMD" ],
...
Are we really looking to save a few dozen CPU cycles in this thing? It
took me at least a minute or two of staring at this thing to figure out
what the heck it was doing.
next prev parent reply other threads:[~2025-03-06 22:00 UTC|newest]
Thread overview: 24+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-03-06 20:49 [PATCH v1 00/12] tools/x86/kcpuid: x86-cpuid-db v2.2 update Ahmed S. Darwish
2025-03-06 20:49 ` [PATCH v1 01/12] tools/x86/kcpuid: Fix error handling Ahmed S. Darwish
2025-03-06 20:49 ` [PATCH v1 02/12] tools/x86/kcpuid: Remove unused local variable Ahmed S. Darwish
2025-03-06 20:49 ` [PATCH v1 03/12] tools/x86/kcpuid: Remove unused global variable Ahmed S. Darwish
2025-03-06 20:49 ` [PATCH v1 04/12] tools/x86/kcpuid: Simplify usage() handling Ahmed S. Darwish
2025-03-06 20:49 ` [PATCH v1 05/12] tools/x86/kcpuid: Refactor CPUID range handling for future expansion Ahmed S. Darwish
2025-03-06 20:49 ` [PATCH v1 06/12] tools/x86/kcpuid: Extend CPUID index mask macro Ahmed S. Darwish
2025-03-06 20:49 ` [PATCH v1 07/12] tools/x86/kcpuid: Add rudimentary CPU vendor detection Ahmed S. Darwish
2025-03-06 21:07 ` Andrew Cooper
2025-03-07 14:06 ` Ahmed S. Darwish
2025-03-06 22:00 ` Dave Hansen [this message]
2025-03-07 13:48 ` Ahmed S. Darwish
2025-03-07 15:46 ` H. Peter Anvin
2025-03-07 15:03 ` Dave Hansen
2025-03-10 14:21 ` Ahmed S. Darwish
2025-03-06 20:49 ` [PATCH v1 08/12] tools/x86/kcpuid: Restrict CPUID scanning to valid vendor ranges Ahmed S. Darwish
2025-03-06 20:49 ` [PATCH v1 09/12] tools/x86/kcpuid: Define Transmeta and Centaur index ranges Ahmed S. Darwish
2025-03-06 20:49 ` [PATCH v1 10/12] tools/x86/kcpuid: Update bitfields to x86-cpuid-db v2.0 Ahmed S. Darwish
2025-03-07 3:18 ` H. Peter Anvin
2025-03-07 15:07 ` Ahmed S. Darwish
2025-03-07 15:27 ` H. Peter Anvin
2025-03-10 14:47 ` Ahmed S. Darwish
2025-03-06 20:49 ` [PATCH v1 11/12] tools/x86/kcpuid: Update bitfields to x86-cpuid-db v2.2 Ahmed S. Darwish
2025-03-06 20:50 ` [PATCH v1 12/12] MAINTAINERS: Include kcpuid under X86 CPUID DATABASE Ahmed S. Darwish
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