Re: [PATCH] perf/events: Replace READ_ONCE() with standard pgtable accessors

[David Hildenbrand (Arm)]

On 4/7/26 05:28, Anshuman Khandual wrote:
> 
> 
> On 27/02/26 11:57 AM, Anshuman Khandual wrote:
>> Replace raw READ_ONCE() dereferences of pgtable entries with corresponding
>> standard page table accessors pxdp_get() in perf_get_pgtable_size(). These
>> accessors default to READ_ONCE() on platforms that don't override them. So
>> there is no functional change on such platforms.
>>
>> However arm64 platform is being extended to support 128 bit page tables via
>> a new architecture feature i.e FEAT_D128 in which case READ_ONCE() will not
>> provide required single copy atomic access for 128 bit page table entries.
>> Although pxdp_get() accessors can later be overridden on arm64 platform to
>> extend required single copy atomicity support on 128 bit entries.
>>
>> Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
>> Cc: David Hildenbrand <david@xxxxxxxxxx>
>> Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
>> Cc: Ingo Molnar <mingo@xxxxxxxxxx>
>> Cc: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
>> Cc: Namhyung Kim <namhyung@xxxxxxxxxx>
>> Cc: linux-perf-users@xxxxxxxxxxxxxxx
>> Cc: linux-mm@xxxxxxxxx
>> Cc: linux-kernel@xxxxxxxxxxxxxxx
>> Acked-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx>
>> Signed-off-by: Anshuman Khandual <anshuman.khandual@xxxxxxx>
>> ---
>> This patch applies both on v7.0-rc1 and mm-unstable.
>>
>> Part of the D128 series but independent. Hence could be considered on its own.
>>
>> https://lore.kernel.org/all/20260224051153.3150613-5-anshuman.khandual@xxxxxxx/
>>
>> Collected Peter's tag from an off list conversation.
> 
> Gentle ping. 
> 
> Still don't see this patch in latest next-20260406. Hence just
> wondering which tree and branch this patch is being picked up ?

It's a trivial change and the last generic code change required for you
arm64 D128 change, right?

I would assume this to go through the tip tree, but if Peter agrees we
could route this (mm) patch through the MM tree.

-- 
Cheers,

David