This patch makes do_swap_page no need to be aware of two different
swap readahead algorithm. Just unify cluster-based and vma-based
readahead function call.

Signed-off-by: Minchan Kim <minc...@kernel.org>
---
 include/linux/swap.h | 17 ++++++++++++-----
 mm/memory.c          | 11 ++++-------
 mm/shmem.c           |  5 ++++-
 mm/swap_state.c      | 21 +++++++++++++++------
 4 files changed, 35 insertions(+), 19 deletions(-)

diff --git a/include/linux/swap.h b/include/linux/swap.h
index 7c7c8b344bc9..9cc330360eac 100644
--- a/include/linux/swap.h
+++ b/include/linux/swap.h
@@ -425,9 +425,11 @@ extern struct page *read_swap_cache_async(swp_entry_t, 
gfp_t,
 extern struct page *__read_swap_cache_async(swp_entry_t, gfp_t,
                        struct vm_area_struct *vma, unsigned long addr,
                        bool *new_page_allocated);
-extern struct page *swapin_readahead(swp_entry_t, gfp_t,
-                       struct vm_area_struct *vma, unsigned long addr);
-extern struct page *do_swap_page_readahead(swp_entry_t fentry, gfp_t gfp_mask,
+extern struct page *cluster_readahead(swp_entry_t entry, gfp_t flag,
+                               struct vm_fault *vmf);
+extern struct page *swapin_readahead(swp_entry_t entry, gfp_t flag,
+                               struct vm_fault *vmf);
+extern struct page *vma_readahead(swp_entry_t fentry, gfp_t gfp_mask,
                                           struct vm_fault *vmf);
 
 /* linux/mm/swapfile.c */
@@ -536,8 +538,13 @@ static inline void put_swap_page(struct page *page, 
swp_entry_t swp)
 {
 }
 
+static inline struct page *cluster_readahead(swp_entry_t, gfp_t gfp_mask
+                                               struct vm_fault *vmf)
+{
+}
+
 static inline struct page *swapin_readahead(swp_entry_t swp, gfp_t gfp_mask,
-                       struct vm_area_struct *vma, unsigned long addr)
+                       struct vm_fault *vmf)
 {
        return NULL;
 }
@@ -547,7 +554,7 @@ static inline bool swap_use_vma_readahead(void)
        return false;
 }
 
-static inline struct page *do_swap_page_readahead(swp_entry_t fentry,
+static inline struct page *vma_readahead(swp_entry_t fentry,
                                gfp_t gfp_mask, struct vm_fault *vmf)
 {
        return NULL;
diff --git a/mm/memory.c b/mm/memory.c
index e955298e4290..ce5e3d7ccc5c 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -2889,7 +2889,8 @@ int do_swap_page(struct vm_fault *vmf)
                if (si->flags & SWP_SYNCHRONOUS_IO &&
                                __swap_count(si, entry) == 1) {
                        /* skip swapcache */
-                       page = alloc_page_vma(GFP_HIGHUSER_MOVABLE, vma, 
vmf->address);
+                       page = alloc_page_vma(GFP_HIGHUSER_MOVABLE, vma,
+                                                       vmf->address);
                        if (page) {
                                __SetPageLocked(page);
                                __SetPageSwapBacked(page);
@@ -2898,12 +2899,8 @@ int do_swap_page(struct vm_fault *vmf)
                                swap_readpage(page, true);
                        }
                } else {
-                       if (swap_use_vma_readahead())
-                               page = do_swap_page_readahead(entry,
-                                       GFP_HIGHUSER_MOVABLE, vmf);
-                       else
-                               page = swapin_readahead(entry,
-                                      GFP_HIGHUSER_MOVABLE, vma, vmf->address);
+                       page = swapin_readahead(entry, GFP_HIGHUSER_MOVABLE,
+                                               vmf);
                        swapcache = page;
                }
 
diff --git a/mm/shmem.c b/mm/shmem.c
index 62dfdc097e44..2522bc0958e1 100644
--- a/mm/shmem.c
+++ b/mm/shmem.c
@@ -1413,9 +1413,12 @@ static struct page *shmem_swapin(swp_entry_t swap, gfp_t 
gfp,
 {
        struct vm_area_struct pvma;
        struct page *page;
+       struct vm_fault vmf;
 
        shmem_pseudo_vma_init(&pvma, info, index);
-       page = swapin_readahead(swap, gfp, &pvma, 0);
+       vmf.vma = &pvma;
+       vmf.address = 0;
+       page = cluster_readahead(swap, gfp, &vmf);
        shmem_pseudo_vma_destroy(&pvma);
 
        return page;
diff --git a/mm/swap_state.c b/mm/swap_state.c
index e3c535fcd2df..5ee53d4ee047 100644
--- a/mm/swap_state.c
+++ b/mm/swap_state.c
@@ -538,11 +538,10 @@ static unsigned long swapin_nr_pages(unsigned long offset)
 }
 
 /**
- * swapin_readahead - swap in pages in hope we need them soon
+ * cluster_readahead - swap in pages in hope we need them soon
  * @entry: swap entry of this memory
  * @gfp_mask: memory allocation flags
- * @vma: user vma this address belongs to
- * @addr: target address for mempolicy
+ * @vmf: fault information
  *
  * Returns the struct page for entry and addr, after queueing swapin.
  *
@@ -556,8 +555,8 @@ static unsigned long swapin_nr_pages(unsigned long offset)
  *
  * Caller must hold down_read on the vma->vm_mm if vma is not NULL.
  */
-struct page *swapin_readahead(swp_entry_t entry, gfp_t gfp_mask,
-                       struct vm_area_struct *vma, unsigned long addr)
+struct page *cluster_readahead(swp_entry_t entry, gfp_t gfp_mask,
+                               struct vm_fault *vmf)
 {
        struct page *page;
        unsigned long entry_offset = swp_offset(entry);
@@ -566,6 +565,8 @@ struct page *swapin_readahead(swp_entry_t entry, gfp_t 
gfp_mask,
        unsigned long mask;
        struct blk_plug plug;
        bool do_poll = true, page_allocated;
+       struct vm_area_struct *vma = vmf->vma;
+       unsigned long addr = vmf->address;
 
        mask = swapin_nr_pages(offset) - 1;
        if (!mask)
@@ -603,6 +604,14 @@ struct page *swapin_readahead(swp_entry_t entry, gfp_t 
gfp_mask,
        return read_swap_cache_async(entry, gfp_mask, vma, addr, do_poll);
 }
 
+struct page *swapin_readahead(swp_entry_t entry, gfp_t gfp_mask,
+                               struct vm_fault *vmf)
+{
+       return swap_use_vma_readahead() ?
+                               vma_readahead(entry, gfp_mask, vmf) :
+                               cluster_readahead(entry, gfp_mask, vmf);
+}
+
 int init_swap_address_space(unsigned int type, unsigned long nr_pages)
 {
        struct address_space *spaces, *space;
@@ -719,7 +728,7 @@ static void swap_ra_info(struct vm_fault *vmf,
        pte_unmap(orig_pte);
 }
 
-struct page *do_swap_page_readahead(swp_entry_t fentry, gfp_t gfp_mask,
+struct page *vma_readahead(swp_entry_t fentry, gfp_t gfp_mask,
                                    struct vm_fault *vmf)
 {
        struct blk_plug plug;
-- 
2.7.4

Reply via email to