| Message ID | 20240226205534.1603748-2-zi.yan@sent.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | Split a folio to any lower order folios | expand |
On 26.02.24 21:55, Zi Yan wrote: > From: Zi Yan <ziy@nvidia.com> > > As multi-size THP support is added, not all THPs are PMD-mapped, thus > during a huge page split, there is no need to always split PMD mapping > in unmap_folio(). Make it conditional. > > Signed-off-by: Zi Yan <ziy@nvidia.com> > --- > mm/huge_memory.c | 7 +++++-- > 1 file changed, 5 insertions(+), 2 deletions(-) > > diff --git a/mm/huge_memory.c b/mm/huge_memory.c > index 28341a5067fb..b20e535e874c 100644 > --- a/mm/huge_memory.c > +++ b/mm/huge_memory.c > @@ -2727,11 +2727,14 @@ void vma_adjust_trans_huge(struct vm_area_struct *vma, > > static void unmap_folio(struct folio *folio) > { > - enum ttu_flags ttu_flags = TTU_RMAP_LOCKED | TTU_SPLIT_HUGE_PMD | > - TTU_SYNC | TTU_BATCH_FLUSH; > + enum ttu_flags ttu_flags = TTU_RMAP_LOCKED | TTU_SYNC | > + TTU_BATCH_FLUSH; > > VM_BUG_ON_FOLIO(!folio_test_large(folio), folio); > > + if (folio_test_pmd_mappable(folio)) > + ttu_flags |= TTU_SPLIT_HUGE_PMD; > + > /* > * Anon pages need migration entries to preserve them, but file > * pages can simply be left unmapped, then faulted back on demand. Reviewed-by: David Hildenbrand <david@redhat.com>
diff --git a/mm/huge_memory.c b/mm/huge_memory.c index 28341a5067fb..b20e535e874c 100644 --- a/mm/huge_memory.c +++ b/mm/huge_memory.c @@ -2727,11 +2727,14 @@ void vma_adjust_trans_huge(struct vm_area_struct *vma, static void unmap_folio(struct folio *folio) { - enum ttu_flags ttu_flags = TTU_RMAP_LOCKED | TTU_SPLIT_HUGE_PMD | - TTU_SYNC | TTU_BATCH_FLUSH; + enum ttu_flags ttu_flags = TTU_RMAP_LOCKED | TTU_SYNC | + TTU_BATCH_FLUSH; VM_BUG_ON_FOLIO(!folio_test_large(folio), folio); + if (folio_test_pmd_mappable(folio)) + ttu_flags |= TTU_SPLIT_HUGE_PMD; + /* * Anon pages need migration entries to preserve them, but file * pages can simply be left unmapped, then faulted back on demand.