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| author | David Hildenbrand <david@redhat.com> | 2025-08-15 14:54:55 +0100 |
|---|---|---|
| committer | Andrew Morton <akpm@linux-foundation.org> | 2025-09-13 16:55:05 -0700 |
| commit | 8cdc4d27019356b0304308eb799484c899b62a87 (patch) | |
| tree | 414259af7af5c19763f6f7fd98ee5cb5d6130a87 /mm/memory.c | |
| parent | mm/huge_memory: convert "tva_flags" to "enum tva_type" (diff) | |
| download | linux-8cdc4d27019356b0304308eb799484c899b62a87.tar.gz linux-8cdc4d27019356b0304308eb799484c899b62a87.zip | |
mm/huge_memory: respect MADV_COLLAPSE with PR_THP_DISABLE_EXCEPT_ADVISED
Let's allow for making MADV_COLLAPSE succeed on areas that neither have
VM_HUGEPAGE nor VM_NOHUGEPAGE when we have THP disabled unless explicitly
advised (PR_THP_DISABLE_EXCEPT_ADVISED).
MADV_COLLAPSE is a clear advice that we want to collapse.
Note that we still respect the VM_NOHUGEPAGE flag, just like
MADV_COLLAPSE always does. So consequently, MADV_COLLAPSE is now only
refused on VM_NOHUGEPAGE with PR_THP_DISABLE_EXCEPT_ADVISED,
including for shmem.
Link: https://lkml.kernel.org/r/20250815135549.130506-4-usamaarif642@gmail.com
Co-developed-by: Usama Arif <usamaarif642@gmail.com>
Signed-off-by: Usama Arif <usamaarif642@gmail.com>
Signed-off-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Baolin Wang <baolin.wang@linux.alibaba.com>
Reviewed-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Reviewed-by: Zi Yan <ziy@nvidia.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Barry Song <baohua@kernel.org>
Cc: Dev Jain <dev.jain@arm.com>
Cc: Jann Horn <jannh@google.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Liam Howlett <liam.howlett@oracle.com>
Cc: Mariano Pache <npache@redhat.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Rik van Riel <riel@surriel.com>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: SeongJae Park <sj@kernel.org>
Cc: Shakeel Butt <shakeel.butt@linux.dev>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Yafang <laoar.shao@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Diffstat (limited to 'mm/memory.c')
| -rw-r--r-- | mm/memory.c | 6 |
1 files changed, 4 insertions, 2 deletions
diff --git a/mm/memory.c b/mm/memory.c index 7b1e8f137fa3..d9de6c056179 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -5332,9 +5332,11 @@ vm_fault_t do_set_pmd(struct vm_fault *vmf, struct folio *folio, struct page *pa * It is too late to allocate a small folio, we already have a large * folio in the pagecache: especially s390 KVM cannot tolerate any * PMD mappings, but PTE-mapped THP are fine. So let's simply refuse any - * PMD mappings if THPs are disabled. + * PMD mappings if THPs are disabled. As we already have a THP, + * behave as if we are forcing a collapse. */ - if (thp_disabled_by_hw() || vma_thp_disabled(vma, vma->vm_flags)) + if (thp_disabled_by_hw() || vma_thp_disabled(vma, vma->vm_flags, + /* forced_collapse=*/ true)) return ret; if (!thp_vma_suitable_order(vma, haddr, PMD_ORDER)) |