From: Borislav Petkov <bp@alien8.de>
To: Dave Hansen <dave.hansen@intel.com>
Cc: Rik van Riel <riel@surriel.com>,
x86@kernel.org, linux-kernel@vger.kernel.org,
kernel-team@meta.com, dave.hansen@linux.intel.com,
luto@kernel.org, peterz@infradead.org, tglx@linutronix.de,
mingo@redhat.com, hpa@zytor.com, akpm@linux-foundation.org,
nadav.amit@gmail.com, zhengqi.arch@bytedance.com,
linux-mm@kvack.org
Subject: Re: [PATCH 05/12] x86/mm: add INVLPGB support code
Date: Mon, 6 Jan 2025 19:14:53 +0100 [thread overview]
Message-ID: <20250106181453.GBZ3wdnUpDfm_t6nvc@fat_crate.local> (raw)
In-Reply-To: <0de32bbc-66e9-4875-af87-7a2fa2e03e39@intel.com>
On Mon, Jan 06, 2025 at 08:50:27AM -0800, Dave Hansen wrote:
> There's some precedent for defining them all up front, like we did for
> invpcid_flush_*().
>
> For INVPCID, there are four variants and two of them got used up front.
> But I get that it's a balancing act between having untested code that
> might bitrot and introducing helpers at a time when someone (Rik) is
> very likely to get all the variants coded up correctly.
That's just silly. We don't add all possible hw interface bits, defines etc,
when they're not going to be used. If we did, the kernel would be an unwieldy
mess of MSRs and their bits, unused insn opcodes and the like.
If someone wants to use them, someone can add them *when* they're needed - not
preemptively, in anticipation that *someone* *might* use them in the future.
Guys, I can't believe I'm actually arguing for something so obvious.
:-\
--
Regards/Gruss,
Boris.
https://people.kernel.org/tglx/notes-about-netiquette
next prev parent reply other threads:[~2025-01-06 18:15 UTC|newest]
Thread overview: 89+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-12-30 17:53 [PATCH v3 00/12] AMD broadcast TLB invalidation Rik van Riel
2024-12-30 17:53 ` [PATCH 01/12] x86/mm: make MMU_GATHER_RCU_TABLE_FREE unconditional Rik van Riel
2024-12-30 18:41 ` Borislav Petkov
2024-12-31 16:11 ` Rik van Riel
2024-12-31 16:19 ` Borislav Petkov
2024-12-31 16:30 ` Rik van Riel
2025-01-02 11:52 ` Borislav Petkov
2025-01-02 19:56 ` Peter Zijlstra
2025-01-03 12:18 ` Borislav Petkov
2025-01-04 16:27 ` Peter Zijlstra
2025-01-06 15:54 ` Dave Hansen
2025-01-06 15:47 ` Rik van Riel
2024-12-30 17:53 ` [PATCH 02/12] x86/mm: remove pv_ops.mmu.tlb_remove_table call Rik van Riel
2024-12-31 3:18 ` Qi Zheng
2024-12-30 17:53 ` [PATCH 03/12] x86/mm: add X86_FEATURE_INVLPGB definition Rik van Riel
2025-01-02 12:04 ` Borislav Petkov
2025-01-03 18:27 ` Rik van Riel
2025-01-03 21:07 ` Borislav Petkov
2024-12-30 17:53 ` [PATCH 04/12] x86/mm: get INVLPGB count max from CPUID Rik van Riel
2025-01-02 12:15 ` Borislav Petkov
2025-01-10 18:44 ` Tom Lendacky
2025-01-10 20:27 ` Rik van Riel
2025-01-10 20:31 ` Tom Lendacky
2025-01-10 20:34 ` Borislav Petkov
2024-12-30 17:53 ` [PATCH 05/12] x86/mm: add INVLPGB support code Rik van Riel
2025-01-02 12:42 ` Borislav Petkov
2025-01-06 16:50 ` Dave Hansen
2025-01-06 17:32 ` Rik van Riel
2025-01-06 18:14 ` Borislav Petkov [this message]
2025-01-14 19:50 ` Rik van Riel
2025-01-03 12:44 ` Borislav Petkov
2024-12-30 17:53 ` [PATCH 06/12] x86/mm: use INVLPGB for kernel TLB flushes Rik van Riel
2025-01-03 12:39 ` Borislav Petkov
2025-01-06 17:21 ` Dave Hansen
2025-01-09 20:16 ` Rik van Riel
2025-01-09 21:18 ` Dave Hansen
2025-01-10 5:31 ` Rik van Riel
2025-01-10 6:07 ` Nadav Amit
2025-01-10 15:14 ` Dave Hansen
2025-01-10 16:08 ` Rik van Riel
2025-01-10 16:29 ` Dave Hansen
2025-01-10 16:36 ` Rik van Riel
2025-01-10 18:53 ` Tom Lendacky
2025-01-10 20:29 ` Rik van Riel
2024-12-30 17:53 ` [PATCH 07/12] x86/tlb: use INVLPGB in flush_tlb_all Rik van Riel
2025-01-06 17:29 ` Dave Hansen
2025-01-06 17:35 ` Rik van Riel
2025-01-06 17:54 ` Dave Hansen
2024-12-30 17:53 ` [PATCH 08/12] x86/mm: use broadcast TLB flushing for page reclaim TLB flushing Rik van Riel
2024-12-30 17:53 ` [PATCH 09/12] x86/mm: enable broadcast TLB invalidation for multi-threaded processes Rik van Riel
2024-12-30 19:24 ` Nadav Amit
2025-01-01 4:42 ` Rik van Riel
2025-01-01 15:20 ` Nadav Amit
2025-01-01 16:15 ` Karim Manaouil
2025-01-01 16:23 ` Rik van Riel
2025-01-02 0:06 ` Nadav Amit
2025-01-03 17:36 ` Jann Horn
2025-01-04 2:55 ` Rik van Riel
2025-01-06 13:04 ` Jann Horn
2025-01-06 14:26 ` Rik van Riel
2025-01-06 14:52 ` Nadav Amit
2025-01-06 16:03 ` Rik van Riel
2025-01-06 18:40 ` Dave Hansen
2025-01-12 2:36 ` Rik van Riel
2024-12-30 17:53 ` [PATCH 10/12] x86,tlb: do targeted broadcast flushing from tlbbatch code Rik van Riel
2024-12-30 17:53 ` [PATCH 11/12] x86/mm: enable AMD translation cache extensions Rik van Riel
2024-12-30 18:25 ` Nadav Amit
2024-12-30 18:27 ` Rik van Riel
2025-01-03 17:49 ` Jann Horn
2025-01-04 3:08 ` Rik van Riel
2025-01-06 13:10 ` Jann Horn
2025-01-06 18:29 ` Sean Christopherson
2025-01-10 19:34 ` Tom Lendacky
2025-01-10 19:45 ` Rik van Riel
2025-01-10 19:58 ` Borislav Petkov
2025-01-10 20:43 ` Rik van Riel
2024-12-30 17:53 ` [PATCH 12/12] x86/mm: only invalidate final translations with INVLPGB Rik van Riel
2025-01-03 18:40 ` Jann Horn
2025-01-12 2:39 ` Rik van Riel
2025-01-06 19:03 ` [PATCH v3 00/12] AMD broadcast TLB invalidation Dave Hansen
2025-01-12 2:46 ` Rik van Riel
2025-01-06 22:49 ` Yosry Ahmed
2025-01-07 3:25 ` Rik van Riel
2025-01-08 1:36 ` Yosry Ahmed
2025-01-09 2:25 ` Andrew Cooper
2025-01-09 2:47 ` Andrew Cooper
2025-01-09 21:32 ` Yosry Ahmed
2025-01-09 23:00 ` Andrew Cooper
2025-01-09 23:26 ` Yosry Ahmed
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