From: Kairui Song <kasong@xxxxxxxxxxx>
No feature change, simply move the routine to a standalone function to
be re-used later. The error path handling is copied from the "out_page"
label, to make the code change minimized for easier reviewing.
Signed-off-by: Kairui Song <kasong@xxxxxxxxxxx>
---
mm/memory.c | 32 ++++----------------------------
mm/swap.h | 8 ++++++++
mm/swap_state.c | 47 +++++++++++++++++++++++++++++++++++++++++++++++
3 files changed, 59 insertions(+), 28 deletions(-)
diff --git a/mm/memory.c b/mm/memory.c
index 7e1f4849463a..81dc9d467f4e 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -3803,7 +3803,6 @@ vm_fault_t do_swap_page(struct vm_fault *vmf)
swp_entry_t entry;
pte_t pte;
vm_fault_t ret = 0;
- void *shadow = NULL;
if (!pte_unmap_same(vmf))
goto out;
@@ -3867,33 +3866,10 @@ vm_fault_t do_swap_page(struct vm_fault *vmf)
if (!folio) {
if (data_race(si->flags & SWP_SYNCHRONOUS_IO) &&
__swap_count(entry) == 1) {
- /* skip swapcache */
- folio = vma_alloc_folio(GFP_HIGHUSER_MOVABLE, 0,
- vma, vmf->address, false);
- page = &folio->page;
- if (folio) {
- __folio_set_locked(folio);
- __folio_set_swapbacked(folio);
-
- if (mem_cgroup_swapin_charge_folio(folio,
- vma->vm_mm, GFP_KERNEL,
- entry)) {
- ret = VM_FAULT_OOM;
- goto out_page;
- }
- mem_cgroup_swapin_uncharge_swap(entry);
-
- shadow = get_shadow_from_swap_cache(entry);
- if (shadow)
- workingset_refault(folio, shadow);
-
- folio_add_lru(folio);
-
- /* To provide entry to swap_read_folio() */
- folio->swap = entry;
- swap_read_folio(folio, true, NULL);
- folio->private = NULL;
- }
+ /* skip swapcache and readahead */
+ folio = swapin_direct(entry, GFP_HIGHUSER_MOVABLE, vmf);
+ if (folio)
+ page = &folio->page;
} else {
page = swapin_readahead(entry, GFP_HIGHUSER_MOVABLE,
vmf);
diff --git a/mm/swap.h b/mm/swap.h
index 758c46ca671e..83eab7b67e77 100644
--- a/mm/swap.h
+++ b/mm/swap.h
@@ -56,6 +56,8 @@ struct folio *swap_cluster_readahead(swp_entry_t entry, gfp_t flag,
struct mempolicy *mpol, pgoff_t ilx);
struct page *swapin_readahead(swp_entry_t entry, gfp_t flag,
struct vm_fault *vmf);
+struct folio *swapin_direct(swp_entry_t entry, gfp_t flag,
+ struct vm_fault *vmf);
static inline unsigned int folio_swap_flags(struct folio *folio)
{
@@ -86,6 +88,12 @@ static inline struct folio *swap_cluster_readahead(swp_entry_t entry,
return NULL;
}
+struct folio *swapin_direct(swp_entry_t entry, gfp_t flag,
+ struct vm_fault *vmf)
+{
+ return NULL;
+}
+
static inline struct page *swapin_readahead(swp_entry_t swp, gfp_t gfp_mask,
struct vm_fault *vmf)
{
diff --git a/mm/swap_state.c b/mm/swap_state.c
index e671266ad772..645f5bcad123 100644
--- a/mm/swap_state.c
+++ b/mm/swap_state.c
@@ -861,6 +861,53 @@ static struct folio *swap_vma_readahead(swp_entry_t targ_entry, gfp_t gfp_mask,
return folio;
}
+/**
+ * swapin_direct - swap in a folio skipping swap cache and readahead
+ * @entry: swap entry of this memory
+ * @gfp_mask: memory allocation flags
+ * @vmf: fault information
+ *
+ * Returns the struct folio for entry and addr after the swap entry is read
+ * in.
+ */
+struct folio *swapin_direct(swp_entry_t entry, gfp_t gfp_mask,
+ struct vm_fault *vmf)
+{
+ struct vm_area_struct *vma = vmf->vma;
+ struct folio *folio;
+ void *shadow = NULL;
+
+ /* skip swapcache */
+ folio = vma_alloc_folio(gfp_mask, 0,
+ vma, vmf->address, false);
+ if (folio) {
+ __folio_set_locked(folio);
+ __folio_set_swapbacked(folio);
+
+ if (mem_cgroup_swapin_charge_folio(folio,
+ vma->vm_mm, GFP_KERNEL,
+ entry)) {
+ folio_unlock(folio);
+ folio_put(folio);
+ return NULL;
+ }
+ mem_cgroup_swapin_uncharge_swap(entry);
+
+ shadow = get_shadow_from_swap_cache(entry);
+ if (shadow)
+ workingset_refault(folio, shadow);
+
+ folio_add_lru(folio);
+
+ /* To provide entry to swap_read_folio() */
+ folio->swap = entry;
+ swap_read_folio(folio, true, NULL);
+ folio->private = NULL;
+ }
+
+ return folio;
+}
+
/**
* swapin_readahead - swap in pages in hope we need them soon
* @entry: swap entry of this memory
--
2.43.0
