Re: [PATCH 5.15.y 0/6] mm/hugetlb: fixes for PMD table sharing (incl. using mmu_gather)

Lorenzo Stoakes (Oracle)
2026-03-12T17:42:20Z

Hi,

This series was sent a ~month ago, is anything holding this up? The underlying
issue is causing a really serious regression so it's quite urgent to get this
pulled ASAP :)

Thanks, Lorenzo

On Wed, Feb 18, 2026 at 12:01:23PM +0100, David Hildenbrand (Arm) wrote:
> Backport of [1] for 5.15. Backport notes are in the individual patches.
>
> I'm also including a cleanup/fix from Miaohe that makes backporting at
> least a bit easier, followed by the fix from Jane.
>
> Tested on x86-64 with the original reproducer.
>
> [1] https://lore.kernel.org/linux-mm/20251223214037.580860-1-david@kernel.org/
>
> Cc: Jane Chu <jane.chu@oracle.com>
> Cc: Harry Yoo <harry.yoo@oracle.com>
> Cc: Oscar Salvador <osalvador@suse.de>
> Cc: Jann Horn <jannh@google.com>
> Cc: Liu Shixin <liushixin2@huawei.com>
> Cc: Muchun Song <muchun.song@linux.dev>
> Cc: Andrew Morton <akpm@linux-foundation.org>
> Cc: Rik van Riel <riel@surriel.com>
> Cc: Laurence Oberman <loberman@redhat.com>
> Cc: Lance Yang <lance.yang@linux.dev>
> Cc: Liu Shixin <liushixin2@huawei.com>
> Cc: Miaohe Lin <linmiaohe@huawei.com>
>
> David Hildenbrand (Red Hat) (4):
> mm/hugetlb: fix hugetlb_pmd_shared()
> mm/hugetlb: fix two comments related to huge_pmd_unshare()
> mm/rmap: fix two comments related to huge_pmd_unshare()
> mm/hugetlb: fix excessive IPI broadcasts when unsharing PMD tables
> using mmu_gather
>
> Jane Chu (1):
> mm/hugetlb: fix copy_hugetlb_page_range() to use ->pt_share_count
>
> Miaohe Lin (1):
> mm/hugetlb: make detecting shared pte more reliable
>
> include/asm-generic/tlb.h | 77 ++++++++++++++++++++-
> include/linux/hugetlb.h | 17 +++--
> include/linux/mm_types.h | 1 +
> mm/hugetlb.c | 141 +++++++++++++++++++-------------------
> mm/mmu_gather.c | 33 +++++++++
> mm/rmap.c | 38 +++++-----
> 6 files changed, 210 insertions(+), 97 deletions(-)
>
> --
> 2.43.0
>