From: Anshuman Khandual <anshuman.khandual@arm.com>
To: Samuel Holland <samuel.holland@sifive.com>,
Palmer Dabbelt <palmer@dabbelt.com>,
Paul Walmsley <pjw@kernel.org>,
linux-riscv@lists.infradead.org
Cc: devicetree@vger.kernel.org, linux-kernel@vger.kernel.org,
linux-mm@kvack.org, Conor Dooley <conor@kernel.org>,
Alexandre Ghiti <alex@ghiti.fr>,
Emil Renner Berthing <kernel@esmil.dk>,
Andrew Morton <akpm@linux-foundation.org>,
Rob Herring <robh+dt@kernel.org>,
Krzysztof Kozlowski <krzk+dt@kernel.org>
Subject: Re: [PATCH v2 02/18] perf/core: Replace READ_ONCE() with standard page table accessors
Date: Thu, 9 Oct 2025 07:33:03 +0530 [thread overview]
Message-ID: <24beaa64-d144-42c3-945f-a37e1cac384d@arm.com> (raw)
In-Reply-To: <20251009015839.3460231-3-samuel.holland@sifive.com>
On 09/10/25 7:27 AM, Samuel Holland wrote:
> Replace READ_ONCE() with standard page table accessors, i.e. pXXp_get(),
> which have a default implementation of READ_ONCE() if the architecture
> does not override them.
>
> Signed-off-by: Samuel Holland <samuel.holland@sifive.com>
> ---
>
> Changes in v2:
> - New patch for v2
>
> kernel/events/core.c | 6 +++---
> 1 file changed, 3 insertions(+), 3 deletions(-)
>
> diff --git a/kernel/events/core.c b/kernel/events/core.c
> index 820127536e62b..952ba4e3d8815 100644
> --- a/kernel/events/core.c
> +++ b/kernel/events/core.c
> @@ -8110,7 +8110,7 @@ static u64 perf_get_pgtable_size(struct mm_struct *mm, unsigned long addr)
> pte_t *ptep, pte;
>
> pgdp = pgd_offset(mm, addr);
> - pgd = READ_ONCE(*pgdp);
> + pgd = pgdp_get(pgdp);
> if (pgd_none(pgd))
> return 0;
>
> @@ -8118,7 +8118,7 @@ static u64 perf_get_pgtable_size(struct mm_struct *mm, unsigned long addr)
> return pgd_leaf_size(pgd);
>
> p4dp = p4d_offset_lockless(pgdp, pgd, addr);
> - p4d = READ_ONCE(*p4dp);
> + p4d = p4dp_get(p4dp);
> if (!p4d_present(p4d))
> return 0;
>
> @@ -8126,7 +8126,7 @@ static u64 perf_get_pgtable_size(struct mm_struct *mm, unsigned long addr)
> return p4d_leaf_size(p4d);
>
> pudp = pud_offset_lockless(p4dp, p4d, addr);
> - pud = READ_ONCE(*pudp);
> + pud = pudp_get(pudp);
> if (!pud_present(pud))
> return 0;
>
This is already under discussion here.
https://lore.kernel.org/all/20251006042622.1743675-1-anshuman.khandual@arm.com/
next prev parent reply other threads:[~2025-10-09 2:03 UTC|newest]
Thread overview: 33+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-10-09 1:57 [PATCH v2 00/18] riscv: Memory type control for platforms with physical memory aliases Samuel Holland
2025-10-09 1:57 ` [PATCH v2 01/18] mm/ptdump: Replace READ_ONCE() with standard page table accessors Samuel Holland
2025-10-09 9:34 ` David Hildenbrand
2025-10-09 1:57 ` [PATCH v2 02/18] perf/core: " Samuel Holland
2025-10-09 2:03 ` Anshuman Khandual [this message]
2025-10-09 1:57 ` [PATCH v2 03/18] mm: Move the fallback definitions of pXXp_get() Samuel Holland
2025-10-09 1:57 ` [PATCH v2 04/18] mm: Always use page table accessor functions Samuel Holland
2025-10-09 2:10 ` Anshuman Khandual
2025-10-09 1:57 ` [PATCH v2 05/18] mm: Allow page table accessors to be non-idempotent Samuel Holland
2025-10-09 1:57 ` [PATCH v2 06/18] riscv: hibernate: Replace open-coded pXXp_get() Samuel Holland
2025-10-09 1:57 ` [PATCH v2 07/18] riscv: mm: Always use page table accessor functions Samuel Holland
2025-10-09 1:57 ` [PATCH v2 08/18] riscv: mm: Simplify set_p4d() and set_pgd() Samuel Holland
2025-10-09 1:57 ` [PATCH v2 09/18] riscv: mm: Deduplicate _PAGE_CHG_MASK definition Samuel Holland
2025-10-09 1:57 ` [PATCH v2 10/18] riscv: ptdump: Only show N and MT bits when enabled in the kernel Samuel Holland
2025-10-09 1:57 ` [PATCH v2 11/18] riscv: mm: Fix up memory types when writing page tables Samuel Holland
2025-10-09 1:57 ` [PATCH v2 12/18] riscv: mm: Expose all page table bits to assembly code Samuel Holland
2025-10-09 1:57 ` [PATCH v2 13/18] riscv: alternative: Add an ALTERNATIVE_3 macro Samuel Holland
2025-10-09 1:57 ` [PATCH v2 14/18] riscv: alternative: Allow calls with alternate link registers Samuel Holland
2025-10-09 1:57 ` [PATCH v2 15/18] dt-bindings: riscv: Describe physical memory regions Samuel Holland
2025-10-09 12:37 ` Rob Herring (Arm)
2025-10-09 1:57 ` [PATCH v2 16/18] riscv: mm: Use physical memory aliases to apply PMAs Samuel Holland
2025-10-10 15:06 ` Emil Renner Berthing
2025-10-10 16:12 ` Samuel Holland
2025-10-10 17:04 ` Emil Renner Berthing
2025-10-10 18:01 ` Samuel Holland
2025-10-10 19:55 ` Emil Renner Berthing
2025-10-09 1:57 ` [PATCH v2 17/18] riscv: dts: starfive: jh7100: Use physical memory ranges for DMA Samuel Holland
2025-10-10 14:19 ` Emil Renner Berthing
2025-10-10 16:51 ` Samuel Holland
2025-10-14 9:14 ` Conor Dooley
2025-10-09 1:57 ` [PATCH v2 18/18] riscv: dts: eswin: eic7700: " Samuel Holland
2025-10-10 1:15 ` [PATCH v2 00/18] riscv: Memory type control for platforms with physical memory aliases Andrew Morton
2025-10-10 17:17 ` Samuel Holland
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