diff options
| author | Ignacio Moreno Gonzalez <Ignacio.MorenoGonzalez@kuka.com> | 2025-05-07 15:28:06 +0200 |
|---|---|---|
| committer | Andrew Morton <akpm@linux-foundation.org> | 2025-05-20 22:49:38 -0700 |
| commit | 7190b3c8bd2b0cde483bd440cf91ba1c518b4261 (patch) | |
| tree | 7e0788ed9349bbbaeb5f7f8295508699261b1195 | |
| parent | 910224c7830d252697dc7fbd57fd1059d266d370 (diff) | |
mm: mmap: map MAP_STACK to VM_NOHUGEPAGE only if THP is enabled
commit c4608d1bf7c6 ("mm: mmap: map MAP_STACK to VM_NOHUGEPAGE") maps the
mmap option MAP_STACK to VM_NOHUGEPAGE. This is also done if
CONFIG_TRANSPARENT_HUGEPAGE is not defined. But in that case, the
VM_NOHUGEPAGE does not make sense.
I discovered this issue when trying to use the tool CRIU to checkpoint and
restore a container. Our running kernel is compiled without
CONFIG_TRANSPARENT_HUGEPAGE. CRIU parses the output of /proc/<pid>/smaps
and saves the "nh" flag. When trying to restore the container, CRIU fails
to restore the "nh" mappings, since madvise() MADV_NOHUGEPAGE always
returns an error because CONFIG_TRANSPARENT_HUGEPAGE is not defined.
Link: https://lkml.kernel.org/r/20250507-map-map_stack-to-vm_nohugepage-only-if-thp-is-enabled-v5-1-c6c38cfefd6e@kuka.com
Fixes: c4608d1bf7c6 ("mm: mmap: map MAP_STACK to VM_NOHUGEPAGE")
Signed-off-by: Ignacio Moreno Gonzalez <Ignacio.MorenoGonzalez@kuka.com>
Acked-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Reviewed-by: Yang Shi <yang@os.amperecomputing.com>
Reviewed-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
| -rw-r--r-- | include/linux/mman.h | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/include/linux/mman.h b/include/linux/mman.h index bce214fece16..f4c6346a8fcd 100644 --- a/include/linux/mman.h +++ b/include/linux/mman.h @@ -155,7 +155,9 @@ calc_vm_flag_bits(struct file *file, unsigned long flags) return _calc_vm_trans(flags, MAP_GROWSDOWN, VM_GROWSDOWN ) | _calc_vm_trans(flags, MAP_LOCKED, VM_LOCKED ) | _calc_vm_trans(flags, MAP_SYNC, VM_SYNC ) | +#ifdef CONFIG_TRANSPARENT_HUGEPAGE _calc_vm_trans(flags, MAP_STACK, VM_NOHUGEPAGE) | +#endif arch_calc_vm_flag_bits(file, flags); } |