Re: fs/proc/task_mmu: Implement IOCTL for efficient page table scanning

From: Muhammad Usama Anjum
Date: Fri Jul 21 2023 - 13:52:05 EST


On 7/21/23 4:29 PM, Michał Mirosław wrote:
> On Fri, Jul 21, 2023 at 03:48:22PM +0500, Muhammad Usama Anjum wrote:
>> On 7/21/23 12:28 AM, Michał Mirosław wrote:
>>> This is a massaged version of patch by Muhammad Usama Anjum [1]
>>> to illustrate my review comments and hopefully push the implementation
>>> efforts closer to conclusion. The changes are:
>> Thank you so much for this effort. I also want to reach conclusion. I'll
>> agree with all the changes which don't affect me. But some requirements
>> aren't being fulfilled with this current design.
> [...]
>> #define PAGE_IS_WPASYNC (1 << 0)
>> #define PAGE_IS_WRITTEN (1 << 1)
>> You have another new flag PAGE_IS_WPASYNC. But there is no application of
>> PAGE_IS_WPASYNC. We must not add a flag which don't have any user.
>
> BTW, I'm not sure I got the PAGE_IS_WPASYNC naming right - this is to
> designate pages that can be write-protected (are UFFD-registered I believe).
PAGE_IS_UFFDWP_REGISTERED or PAGE_IS_WP_REG?

>
> Best Regards
> Michał Mirosław

--
BR,
Muhammad Usama Anjum