From: Peter Zijlstra <peterz@infradead.org>
To: Mark Rutland <mark.rutland@arm.com>
Cc: Anshuman Khandual <anshuman.khandual@arm.com>,
linux-arm-kernel@lists.infradead.org,
Catalin Marinas <catalin.marinas@arm.com>,
Will Deacon <will@kernel.org>,
Ryan Roberts <ryan.roberts@arm.com>,
Lorenzo Stoakes <lorenzo.stoakes@oracle.com>,
Andrew Morton <akpm@linux-foundation.org>,
David Hildenbrand <david@kernel.org>,
Mike Rapoport <rppt@kernel.org>,
Linu Cherian <linu.cherian@arm.com>,
linux-kernel@vger.kernel.org, linux-mm@kvack.org,
Ingo Molnar <mingo@redhat.com>,
Arnaldo Carvalho de Melo <acme@kernel.org>,
Namhyung Kim <namhyung@kernel.org>,
linux-perf-users@vger.kernel.org
Subject: Re: [RFC V1 04/16] perf/events: Replace READ_ONCE() with standard pgtable accessors
Date: Tue, 24 Feb 2026 11:41:34 +0100 [thread overview]
Message-ID: <20260224104134.GW1395266@noisy.programming.kicks-ass.net> (raw)
In-Reply-To: <aZ14lUwuA86aiOH-@J2N7QTR9R3>
On Tue, Feb 24, 2026 at 10:08:21AM +0000, Mark Rutland wrote:
> On Tue, Feb 24, 2026 at 10:41:41AM +0530, Anshuman Khandual wrote:
> > Replace READ_ONCE() with standard page table accessors i.e pxdp_get() which
> > anyways default into READ_ONCE() in cases where platform do not override.
>
> For each of the patches where you make this sort of change, please
> explain in the commit message *why* it is necessary to do this.
>
> IIUC the entire point of this is that in subsequent patches, arm64 will
> need to use something other than READ_ONCE() for all pXX levels in order
> to support D128 translation tables.
>
> Spelling that out in the commit message makes it much easier for
> reviewers to see what's going on, and to focus any discussion/questions,
> e.g. *why* won't READ_ONCE() work?
That, and only being sent *one* patch, I have no clue what the rest of
them are doing. Didn't even get 0/n.
I hate people sending me just one patch; just send the whole series
already.
next prev parent reply other threads:[~2026-02-24 10:41 UTC|newest]
Thread overview: 24+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-02-24 5:11 [RFC V1 00/16] arm64/mm: Enable 128 bit page table entries Anshuman Khandual
2026-02-24 5:11 ` [RFC V1 01/16] mm: Abstract printing of pxd_val() Anshuman Khandual
2026-02-24 5:11 ` [RFC V1 02/16] mm: Add read-write accessors for vm_page_prot Anshuman Khandual
2026-02-24 5:11 ` [RFC V1 03/16] mm: Replace READ_ONCE() in pud_trans_unstable() Anshuman Khandual
2026-02-24 5:11 ` [RFC V1 04/16] perf/events: Replace READ_ONCE() with standard pgtable accessors Anshuman Khandual
2026-02-24 8:48 ` Peter Zijlstra
2026-02-24 10:08 ` Mark Rutland
2026-02-24 10:41 ` Peter Zijlstra [this message]
2026-02-24 11:22 ` Ryan Roberts
2026-02-24 12:49 ` Anshuman Khandual
2026-02-24 12:39 ` Anshuman Khandual
2026-02-24 12:53 ` Anshuman Khandual
2026-02-24 5:11 ` [RFC V1 05/16] arm64/mm: Convert READ_ONCE() as pmdp_get() while accessing PMD Anshuman Khandual
2026-02-24 5:11 ` [RFC V1 06/16] arm64/mm: Convert READ_ONCE() as pudp_get() while accessing PUD Anshuman Khandual
2026-02-24 5:11 ` [RFC V1 07/16] arm64/mm: Convert READ_ONCE() as p4dp_get() while accessing P4D Anshuman Khandual
2026-02-24 5:11 ` [RFC V1 08/16] arm64/mm: Convert READ_ONCE() as pgdp_get() while accessing PGD Anshuman Khandual
2026-02-24 5:11 ` [RFC V1 09/16] arm64/mm: Route all pgtable reads via ptdesc_get() Anshuman Khandual
2026-02-24 5:11 ` [RFC V1 10/16] arm64/mm: Route all pgtable writes via ptdesc_set() Anshuman Khandual
2026-02-24 5:11 ` [RFC V1 11/16] arm64/mm: Route all pgtable atomics to central helpers Anshuman Khandual
2026-02-24 5:11 ` [RFC V1 12/16] arm64/mm: Abstract printing of pxd_val() Anshuman Khandual
2026-02-24 5:11 ` [RFC V1 13/16] arm64/mm: Override read-write accessors for vm_page_prot Anshuman Khandual
2026-02-24 5:11 ` [RFC V1 14/16] arm64/mm: Enable fixmap with 5 level page table Anshuman Khandual
2026-02-24 5:11 ` [RFC V1 15/16] arm64/mm: Add macros __tlb_asid_level and __tlb_range Anshuman Khandual
2026-02-24 5:11 ` [RFC V1 16/16] arm64/mm: Add initial support for FEAT_D128 page tables Anshuman Khandual
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