Re: [PATCH] mm: remove zap_page_range and create zap_vma_pages

From: Peter Xu
Date: Wed Jan 04 2023 - 11:50:44 EST


On Tue, Jan 03, 2023 at 04:27:32PM -0800, Mike Kravetz wrote:
> zap_page_range was originally designed to unmap pages within an address
> range that could span multiple vmas. While working on [1], it was
> discovered that all callers of zap_page_range pass a range entirely within
> a single vma. In addition, the mmu notification call within zap_page
> range does not correctly handle ranges that span multiple vmas. When
> crossing a vma boundary, a new mmu_notifier_range_init/end call pair
> with the new vma should be made.
>
> Instead of fixing zap_page_range, do the following:
> - Create a new routine zap_vma_pages() that will remove all pages within
> the passed vma. Most users of zap_page_range pass the entire vma and
> can use this new routine.
> - For callers of zap_page_range not passing the entire vma, instead call
> zap_page_range_single().
> - Remove zap_page_range.
>
> [1] https://lore.kernel.org/linux-mm/20221114235507.294320-2-mike.kravetz@xxxxxxxxxx/
> Suggested-by: Peter Xu <peterx@xxxxxxxxxx>
> Signed-off-by: Mike Kravetz <mike.kravetz@xxxxxxxxxx>

Acked-by: Peter Xu <peterx@xxxxxxxxxx>

--
Peter Xu