On 24.10.22 22:48, Peter Xu wrote:
PTE markers are ideal mechanism for things like SWP_SWAPIN_ERROR. Using a
whole swap entry type for this purpose can be an overkill, especially if we
already have PTE markers. Define a new bit for swapin error and replace it
with pte markers. Then we can safely drop SWP_SWAPIN_ERROR and give one
device slot back to swap.
We used to have SWP_SWAPIN_ERROR taking the page pfn as part of the swap
entry, but it's never used. Neither do I see how it can be useful because
normally the swapin failure should not be caused by a bad page but bad swap
device. Drop it alongside.
[...]
-#define PTE_MARKER_UFFD_WP BIT(0)
-#define PTE_MARKER_MASK (PTE_MARKER_UFFD_WP)
+#define PTE_MARKER_UFFD_WP BIT(0)
+#define PTE_MARKER_SWAP_ERROR BIT(1)
I'd suggest to keep the term SWAPIN. An error happened during swapin,
which is why the page is corrupted.
(I remember that we discussed naming details in the original series and
SWAPIN was the conclusion)
--
Thanks,
David / dhildenb
