From: Borislav Petkov <bp@alien8.de>
To: Rik van Riel <riel@surriel.com>
Cc: x86@kernel.org, linux-kernel@vger.kernel.org,
peterz@infradead.org, dave.hansen@linux.intel.com,
zhengqi.arch@bytedance.com, nadav.amit@gmail.com,
thomas.lendacky@amd.com, kernel-team@meta.com,
linux-mm@kvack.org, akpm@linux-foundation.org, jannh@google.com
Subject: Re: [PATCH v4 01/12] x86/mm: make MMU_GATHER_RCU_TABLE_FREE unconditional
Date: Tue, 14 Jan 2025 13:32:28 +0100 [thread overview]
Message-ID: <20250114123228.GAZ4ZZXK7Vd-KlM-Cc@fat_crate.local> (raw)
In-Reply-To: <20250112155453.1104139-2-riel@surriel.com>
On Sun, Jan 12, 2025 at 10:53:45AM -0500, Rik van Riel wrote:
> Currently x86 uses CONFIG_MMU_GATHER_TABLE_FREE when using
> paravirt, and not when running on bare metal.
>
> There is no real good reason to do things differently for
> each setup. Make them all the same.
>
> Currently get_user_pages_fast synchronizes against page table
> freeing in two different ways:
> - on bare metal, by blocking IRQs, which block TLB flush IPIs
> - on paravirt, with MMU_GATHER_RCU_TABLE_FREE
>
> This is done because some paravirt TLB flush implementations
> handle the TLB flush in the hypervisor, and will do the flush
> even when the target CPU has interrupts disabled.
>
> After this change, the synchronization between get_user_pages_fast
get_user_pages_fast() - make it look like a function.
Avoid having "This patch" or "This commit" or "After this change", etc in the
commit message. It is tautologically useless so use imperative tone directly:
"Always handle page table freeing with..."
> and page table freeing is always handled with MMU_GATHER_RCU_TABLE_FREE,
> which allows bare metal to also do TLB flushes while interrupts are
> disabled.
--
Regards/Gruss,
Boris.
https://people.kernel.org/tglx/notes-about-netiquette
next prev parent reply other threads:[~2025-01-14 12:32 UTC|newest]
Thread overview: 36+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-01-12 15:53 [RFC PATCH v4 00/10] AMD broadcast TLB invalidation Rik van Riel
2025-01-12 15:53 ` [PATCH v4 01/12] x86/mm: make MMU_GATHER_RCU_TABLE_FREE unconditional Rik van Riel
2025-01-14 12:32 ` Borislav Petkov [this message]
2025-01-12 15:53 ` [PATCH v4 02/12] x86/mm: remove pv_ops.mmu.tlb_remove_table call Rik van Riel
2025-01-12 15:53 ` [PATCH v4 03/12] x86/mm: consolidate full flush threshold decision Rik van Riel
2025-01-12 15:53 ` [PATCH v4 04/12] x86/mm: get INVLPGB count max from CPUID Rik van Riel
2025-01-13 15:50 ` Jann Horn
2025-01-13 21:08 ` Rik van Riel
2025-01-13 22:53 ` Tom Lendacky
2025-01-12 15:53 ` [PATCH v4 05/12] x86/mm: add INVLPGB support code Rik van Riel
2025-01-13 14:21 ` Tom Lendacky
2025-01-13 21:10 ` Rik van Riel
2025-01-14 14:29 ` Tom Lendacky
2025-01-14 15:05 ` Dave Hansen
2025-01-14 15:23 ` Tom Lendacky
2025-01-14 15:47 ` Rik van Riel
2025-01-14 16:30 ` Tom Lendacky
2025-01-14 16:41 ` Dave Hansen
2025-01-13 17:24 ` Jann Horn
2025-01-14 1:33 ` Rik van Riel
2025-01-14 18:24 ` Michael Kelley
2025-01-12 15:53 ` [PATCH v4 06/12] x86/mm: use INVLPGB for kernel TLB flushes Rik van Riel
2025-01-12 15:53 ` [PATCH v4 07/12] x86/tlb: use INVLPGB in flush_tlb_all Rik van Riel
2025-01-12 15:53 ` [PATCH v4 08/12] x86/mm: use broadcast TLB flushing for page reclaim TLB flushing Rik van Riel
2025-01-12 15:53 ` [PATCH v4 09/12] x86/mm: enable broadcast TLB invalidation for multi-threaded processes Rik van Riel
2025-01-13 13:09 ` Nadav Amit
2025-01-14 3:13 ` Rik van Riel
2025-01-12 15:53 ` [PATCH v4 10/12] x86,tlb: do targeted broadcast flushing from tlbbatch code Rik van Riel
2025-01-13 17:05 ` Jann Horn
2025-01-13 17:48 ` Jann Horn
2025-01-13 21:16 ` Rik van Riel
2025-01-12 15:53 ` [PATCH v4 11/12] x86/mm: enable AMD translation cache extensions Rik van Riel
2025-01-13 11:32 ` Andrew Cooper
2025-01-14 1:28 ` Rik van Riel
2025-01-12 15:53 ` [PATCH v4 12/12] x86/mm: only invalidate final translations with INVLPGB Rik van Riel
2025-01-13 17:11 ` Jann Horn
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20250114123228.GAZ4ZZXK7Vd-KlM-Cc@fat_crate.local \
--to=bp@alien8.de \
--cc=akpm@linux-foundation.org \
--cc=dave.hansen@linux.intel.com \
--cc=jannh@google.com \
--cc=kernel-team@meta.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=nadav.amit@gmail.com \
--cc=peterz@infradead.org \
--cc=riel@surriel.com \
--cc=thomas.lendacky@amd.com \
--cc=x86@kernel.org \
--cc=zhengqi.arch@bytedance.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox