Re: [PATCH] mm: add access/dirty bit on numa page fault

From: maobibo
Date: Wed Mar 16 2022 - 21:09:25 EST




On 03/16/2022 05:42 PM, Anshuman Khandual wrote:
>
>
> On 3/16/22 12:33, maobibo wrote:
>>
>> On 03/16/2022 02:43 PM, Anshuman Khandual wrote:
>>>
>>> On 3/16/22 06:38, Bibo Mao wrote:
>>>> During numa page fault, dirty bit can be added for old pte if
>>>> fail to migrate on write fault. And if it succeeds to migrate,
>>>> access bit can be added for migrated new pte, also dirty bit
>>>> can be added for write fault.
>>> The current code does not set the access and dirty bits when ever
>>> applicable i.e on FAULT_FLAG_WRITE, on the pte (old if migration
>>> fails, new if migration succeeds) ? Did not this cause any problem
>>> earlier ? I am wondering how this might have gone unnoticed.
>
>> On arm/x86 platform hw will set access/dirty bits automatically,
>> however on MIPS platform access/dirty bits are set by software in next
>> page fault, it is relatively easier to watch on MIPS platform.
>
> Could you please update this in the commit message as well ?

sure, will do.

regards
bibo, mao