On 24.06.24 13:48, Yosry Ahmed wrote:
On Tue, Jun 18, 2024 at 8:10 AM David Hildenbrand <david@xxxxxxxxxx> wrote:
Let's simplify and reduce code indentation. In the RMAP_LEVEL_PTE case, we
already check for nr when computing partially_mapped.
For RMAP_LEVEL_PMD, it's a bit more confusing. Likely, we don't need the
"nr" check, but we could have "nr < nr_pmdmapped" also if we stumbled
into the "/* Raced ahead of another remove and an add? */" case. So
let's simply move the nr check in there.
Note that partially_mapped is always false for small folios.
No functional change intended.
Cc: Yosry Ahmed <yosryahmed@xxxxxxxxxx>
Signed-off-by: David Hildenbrand <david@xxxxxxxxxx>
Makes sense to me. FWIW:
Reviewed-by: Yosry Ahmed <yosryahmed@xxxxxxxxxx>
---
mm/rmap.c | 10 ++++------
1 file changed, 4 insertions(+), 6 deletions(-)
diff --git a/mm/rmap.c b/mm/rmap.c
index afec4b6800caf..aa900e46cdf82 100644
--- a/mm/rmap.c
+++ b/mm/rmap.c
@@ -1551,11 +1551,12 @@ static __always_inline void __folio_remove_rmap(struct folio *folio,
}
}
- partially_mapped = nr < nr_pmdmapped;
+ partially_mapped = nr && nr < nr_pmdmapped;
break;
}
- if (nr) {
+ if (partially_mapped && folio_test_anon(folio) &&
+ list_empty(&folio->_deferred_list))
/*
* Queue anon large folio for deferred split if at least one
* page of the folio is unmapped and at least one page
@@ -1563,10 +1564,7 @@ static __always_inline void __folio_remove_rmap(struct folio *folio,
*
* Check partially_mapped first to ensure it is a large folio.
*/
- if (folio_test_anon(folio) && partially_mapped &&
- list_empty(&folio->_deferred_list))
- deferred_split_folio(folio);
- }
+ deferred_split_folio(folio);
FWIW, I prefer moving the comment out of the one-line if block as you
originally suggested in [1].
[1]https://lore.kernel.org/lkml/1a408ed1-7e81-457e-a205-db274b4d6b78@xxxxxxxxxx/
Sorry for the late reply, crazy times here.
Let me do that and resend, thanks!
--
Cheers,
David / dhildenb
