diff options
| author | Peter Xu <peterx@redhat.com> | 2022-10-30 17:41:51 -0400 |
|---|---|---|
| committer | Andrew Morton <akpm@linux-foundation.org> | 2022-11-30 15:58:46 -0800 |
| commit | 15520a3f046998e3f57e695743e99b0875e2dae7 (patch) | |
| tree | 831e756367bc6484cba5fcafc6d782b153e1b4b3 /mm | |
| parent | ca92ea3dc5a2b01f98e9f02b7a6bc03be06fe124 (diff) | |
mm: use pte markers for swap errors
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.
Link: https://lkml.kernel.org/r/20221030214151.402274-3-peterx@redhat.com
Signed-off-by: Peter Xu <peterx@redhat.com>
Reviewed-by: Huang Ying <ying.huang@intel.com>
Reviewed-by: Miaohe Lin <linmiaohe@huawei.com>
Acked-by: David Hildenbrand <david@redhat.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Naoya Horiguchi <naoya.horiguchi@nec.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Diffstat (limited to 'mm')
| -rw-r--r-- | mm/memory.c | 6 | ||||
| -rw-r--r-- | mm/shmem.c | 2 | ||||
| -rw-r--r-- | mm/swapfile.c | 2 |
3 files changed, 6 insertions, 4 deletions
diff --git a/mm/memory.c b/mm/memory.c index b79d27533722..142c4229549b 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -3668,6 +3668,10 @@ static vm_fault_t handle_pte_marker(struct vm_fault *vmf) if (WARN_ON_ONCE(!marker)) return VM_FAULT_SIGBUS; + /* Higher priority than uffd-wp when data corrupted */ + if (marker & PTE_MARKER_SWAPIN_ERROR) + return VM_FAULT_SIGBUS; + if (pte_marker_entry_uffd_wp(entry)) return pte_marker_handle_uffd_wp(vmf); @@ -3727,8 +3731,6 @@ vm_fault_t do_swap_page(struct vm_fault *vmf) put_page(vmf->page); } else if (is_hwpoison_entry(entry)) { ret = VM_FAULT_HWPOISON; - } else if (is_swapin_error_entry(entry)) { - ret = VM_FAULT_SIGBUS; } else if (is_pte_marker_entry(entry)) { ret = handle_pte_marker(vmf); } else { diff --git a/mm/shmem.c b/mm/shmem.c index 0a7c4a748811..7428ae3fa4b9 100644 --- a/mm/shmem.c +++ b/mm/shmem.c @@ -1682,7 +1682,7 @@ static void shmem_set_folio_swapin_error(struct inode *inode, pgoff_t index, swp_entry_t swapin_error; void *old; - swapin_error = make_swapin_error_entry(&folio->page); + swapin_error = make_swapin_error_entry(); old = xa_cmpxchg_irq(&mapping->i_pages, index, swp_to_radix_entry(swap), swp_to_radix_entry(swapin_error), 0); diff --git a/mm/swapfile.c b/mm/swapfile.c index 72e481aacd5d..03fe0949f6b2 100644 --- a/mm/swapfile.c +++ b/mm/swapfile.c @@ -1781,7 +1781,7 @@ static int unuse_pte(struct vm_area_struct *vma, pmd_t *pmd, pte_t pteval; dec_mm_counter(vma->vm_mm, MM_SWAPENTS); - pteval = swp_entry_to_pte(make_swapin_error_entry(page)); + pteval = swp_entry_to_pte(make_swapin_error_entry()); set_pte_at(vma->vm_mm, addr, pte, pteval); swap_free(entry); ret = 0; |