Re: [PATCH 2/2] mm/damon/vaddr: remove comparison between mm and last_mm when checking region accesses

SeongJae Park
2022-08-26T17:16:42Z

Hi Kaixu,

On Fri, 26 Aug 2022 16:31:18 +0800 xiakaixu1987@gmail.com wrote:

> From: Kaixu Xia <kaixuxia@tencent.com>
>
> The damon regions that belong to the same damon target have the same
> 'struct mm_struct *mm', so it's unnecessary to compare the mm and last_mm
> objects among the damon regions in one damon target when checking accesses.

There could be multiple targets, and 'damon_va_check_accesses()' calls
'__damon_va_check_accesses()' for all the targets. However,
'damon_va_check_accesses()' doesn't note if '__damon_va_check_accesses()' is
called with a target that same to the target it was called with for the last
time. Hence the check is necessary.

If I'm missing something, please let me know.

Thanks,
SJ …