| From: |
| "Vishal Moola (Oracle)" <vishal.moola-AT-gmail.com> |
| To: |
| linux-kernel-AT-vger.kernel.org, linux-mm-AT-kvack.org, x86-AT-kernel.org, "Mike Rapoport (Microsoft)" <rppt-AT-kernel.org> |
| Subject: |
| [PATCH v3 0/3] Convert 64-bit x86/mm/pat to ptdescs |
| Date: |
| Mon, 02 Feb 2026 09:20:02 -0800 |
| Message-ID: |
| <20260202172005.683870-1-vishal.moola@gmail.com> |
| Cc: |
| akpm-AT-linux-foundation.org, "Matthew Wilcox (Oracle)" <willy-AT-infradead.org>, Dave Hansen <dave.hansen-AT-linux.intel.com>, Andy Lutomirski <luto-AT-kernel.org>, Peter Zijlstra <peterz-AT-infradead.org>, "Vishal Moola (Oracle)" <vishal.moola-AT-gmail.com> |
| Archive-link: |
| Article |
x86/mm/pat should be using ptdescs. One line has already been
converted to pagetable_free(), while the allocation sites use
get_free_pages(). This causes issues separately allocating ptdescs
from struct page.
These patches convert the allocation/free sites to use ptdescs. In
the short term, this helps enable Matthew's work to allocate frozen
pagetables[1]. And in the long term, this will help us cleanly split
ptdesc allocations from struct page.
The pgd_list should also be using ptdescs (for 32bit in this file). This
can be done in a different patchset since there's other users of pgd_list
that still need to be converted.
[1] https://lore.kernel.org/linux-mm/20251113140448.1814860-1...
[2] https://lore.kernel.org/linux-mm/20251020001652.2116669-1...
------
I've also tested this on a tree that separately allocates ptdescs. That
didn't find any lingering alloc/free issues.
Based on current mm-new.
v3:
- Move comment regarding 32-bit conversions into the cover letter
- Correct the handling for the pagetable_alloc() error path
Vishal Moola (Oracle) (3):
x86/mm/pat: Convert pte code to use ptdescs
x86/mm/pat: Convert pmd code to use ptdescs
x86/mm/pat: Convert split_large_page() to use ptdescs
arch/x86/mm/pat/set_memory.c | 56 +++++++++++++++++++++---------------
1 file changed, 33 insertions(+), 23 deletions(-)
--
2.52.0
