Re: [PATCH v4] arm64/mm: Optimize loop to reduce redundant operations of contpte_ptep_get

David Hildenbrand
2025-05-09T10:24:58Z

On 09.05.25 11:17, Xavier wrote:
>
>
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> At 2025-05-08 16:30:14, "David Hildenbrand" <david@redhat.com> wrote:
>> On 08.05.25 09:03, Xavier Xia wrote:
>>> This commit optimizes the contpte_ptep_get and contpte_ptep_get_lockless
>>> function by adding early termination logic. It checks if the dirty and
>>> young bits of orig_pte are already set and skips redundant bit-setting
>>> operations during the loop. This reduces unnecessary iterations and
>>> improves performance.
>>>
>>> In order to verify the optimization performance, a test function has been
>>> designed. The function's execution time and instruction statistics have
>>> been traced using perf, and the following are the operation results on a
>>> certain Qualcomm mobile phone chip:
>>
>> For the future, please don't post vN+1 as reply to vN.
>
> I will pay attention to it when I submit it later. Thank you for the reminder.

The rationale is that many people will just treat it as some discussion
noise as part of vN and not really have a closer look, waiting for vN+1.

--
Cheers,

David / dhildenb