lkml.org 
[lkml]   [2024]   [May]   [8]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH v4 2/3] mm/rmap: integrate PMD-mapped folio splitting into pagewalk loop
On Wed, May 08, 2024 at 10:56:34AM -0400, Zi Yan wrote:

> Lance is improving try_to_unmap_one() to support unmapping PMD THP as a whole,
> so he moves split_huge_pmd_address() inside while (page_vma_mapped_walk(&pvmw))
> and after mmu_notifier_invalidate_range_start() as split_huge_pmd_locked()
> and does not include the mmu notifier ops inside split_huge_pmd_address().
> I wonder if that could cause issues, since the mmu_notifier_invalidate_range_start()
> before the while loop only has range of the original address and
> split huge pmd can affect the entire PMD address range and these two ranges
> might not be the same.

That does not sound entirely good..

I suppose it depends on what split does, if the MM page table has the
same translation before and after split then perhaps no invalidation
is even necessary.

Jason



\
 
 \ /
  Last update: 2024-05-08 17:53    [W:0.052 / U:0.020 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site