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

[Michał Mirosław]

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).

Best Regards
Michał Mirosław