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authorDavid Hildenbrand <david@redhat.com>2025-08-15 14:54:55 +0100
committerAndrew Morton <akpm@linux-foundation.org>2025-09-13 16:55:05 -0700
commit8cdc4d27019356b0304308eb799484c899b62a87 (patch)
tree414259af7af5c19763f6f7fd98ee5cb5d6130a87 /mm/huge_memory.c
parent1f1c061089dcd274befa0c76fb9f6e253a8368c0 (diff)
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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/huge_memory.c')
-rw-r--r--mm/huge_memory.c5
1 files changed, 3 insertions, 2 deletions
diff --git a/mm/huge_memory.c b/mm/huge_memory.c
index 899d9ac86ecd..d89992b65acc 100644
--- a/mm/huge_memory.c
+++ b/mm/huge_memory.c
@@ -104,7 +104,8 @@ unsigned long __thp_vma_allowable_orders(struct vm_area_struct *vma,
{
const bool smaps = type == TVA_SMAPS;
const bool in_pf = type == TVA_PAGEFAULT;
- const bool enforce_sysfs = type != TVA_FORCED_COLLAPSE;
+ const bool forced_collapse = type == TVA_FORCED_COLLAPSE;
+ const bool enforce_sysfs = !forced_collapse;
unsigned long supported_orders;
/* Check the intersection of requested and supported orders. */
@@ -122,7 +123,7 @@ unsigned long __thp_vma_allowable_orders(struct vm_area_struct *vma,
if (!vma->vm_mm) /* vdso */
return 0;
- if (thp_disabled_by_hw() || vma_thp_disabled(vma, vm_flags))
+ if (thp_disabled_by_hw() || vma_thp_disabled(vma, vm_flags, forced_collapse))
return 0;
/* khugepaged doesn't collapse DAX vma, but page fault is fine. */