On 16.08.23 17:12, Matthew Wilcox (Oracle) wrote:
Because THP_SWAP uses page->private for each page, we must not use
the space which overlaps that field for anything which would conflict
with that. We avoid the conflict on 32-bit systems by disallowing
THP_SWAP on 32-bit.
Signed-off-by: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx>
---
include/linux/mm_types.h | 14 +++++++++++++-
1 file changed, 13 insertions(+), 1 deletion(-)
diff --git a/include/linux/mm_types.h b/include/linux/mm_types.h
index 659c7b84726c..3880b3f2e321 100644
--- a/include/linux/mm_types.h
+++ b/include/linux/mm_types.h
@@ -340,8 +340,11 @@ struct folio {
atomic_t _pincount;
#ifdef CONFIG_64BIT
unsigned int _folio_nr_pages;
-#endif
+ /* 4 byte gap here */
/* private: the union with struct page is transitional */
+ /* Fix THP_SWAP to not use tail->private */
+ unsigned long _private_1;
If you could give
https://lkml.kernel.org/r/b887e764-ffa3-55ee-3c44-69cb15f8a115@xxxxxxxxxx
a quick glimpse to see if anything important jumps at you, that would be
great.
That really should be fixed.
--
Cheers,
David / dhildenb
