This change disables swap vma readahead. This is because swap_ra_info()
updates vma->swap_readahead_info, which is not feasible when operating
on pseudo-vmas.
This is a crude temporary solution. It may be possible to use a per-mm
swap_readahead_info instead, or if not, to explicitly fetch the vma of
record when updating the swap readahead statistics.
Signed-off-by: Michel Lespinasse <walken@xxxxxxxxxx>
---
mm/swap_state.c | 6 ++++++
1 file changed, 6 insertions(+)
diff --git mm/swap_state.c mm/swap_state.c
index 8e7ce9a9bc5e..c9cdfd9c785e 100644
--- mm/swap_state.c
+++ mm/swap_state.c
@@ -298,6 +298,12 @@ void free_pages_and_swap_cache(struct page **pages, int nr)
static inline bool swap_use_vma_readahead(void)
{
+ /*
+ * vma readahead overwrites vma->swap_readahead_info,
+ * which requires some form of vma locking...
+ */
+ return false;
+
return READ_ONCE(enable_vma_readahead) && !atomic_read(&nr_rotate_swap);
}
--
2.25.0.341.g760bfbb309-goog
