mm/rmap: make rmap_walk to get the rmap_walk_control argument

In each rmap traverse case, there is some difference so that we need
function pointers and arguments to them in order to handle these

For this purpose, struct rmap_walk_control is introduced in this patch,
and will be extended in following patch.  Introducing and extending are
separate, because it clarify changes.

Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Reviewed-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Hugh Dickins <hughd@google.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Hillf Danton <dhillf@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/include/linux/ksm.h b/include/linux/ksm.h
index 45c9b6a17bcb5e7037ce01173f51ec6383d681c7..0eef8cb0baf72be865e20f311c0121ec8200be88 100644 (file)
--- a/include/linux/ksm.h
+++ b/include/linux/ksm.h
@@ -76,8 +76,7 @@ struct page *ksm_might_need_to_copy(struct page *page,
 int page_referenced_ksm(struct page *page,
                        struct mem_cgroup *memcg, unsigned long *vm_flags);
 int try_to_unmap_ksm(struct page *page, enum ttu_flags flags);
-int rmap_walk_ksm(struct page *page, int (*rmap_one)(struct page *,
-                 struct vm_area_struct *, unsigned long, void *), void *arg);
+int rmap_walk_ksm(struct page *page, struct rmap_walk_control *rwc);
 void ksm_migrate_page(struct page *newpage, struct page *oldpage);
 
 #else  /* !CONFIG_KSM */
@@ -120,8 +119,8 @@ static inline int try_to_unmap_ksm(struct page *page, enum ttu_flags flags)
        return 0;
 }
 
-static inline int rmap_walk_ksm(struct page *page, int (*rmap_one)(struct page*,
-               struct vm_area_struct *, unsigned long, void *), void *arg)
+static inline int rmap_walk_ksm(struct page *page,
+                       struct rmap_walk_control *rwc)
 {
        return 0;
 }

diff --git a/include/linux/rmap.h b/include/linux/rmap.h
index 6dacb93a6d94a3f710706b6ed2e16a3fa5ad5e4e..6a456ce6de20bfb63d16c47ea7a97896d6f7cf11 100644 (file)
--- a/include/linux/rmap.h
+++ b/include/linux/rmap.h
@@ -235,11 +235,16 @@ struct anon_vma *page_lock_anon_vma_read(struct page *page);
 void page_unlock_anon_vma_read(struct anon_vma *anon_vma);
 int page_mapped_in_vma(struct page *page, struct vm_area_struct *vma);
 
+struct rmap_walk_control {
+       void *arg;
+       int (*rmap_one)(struct page *page, struct vm_area_struct *vma,
+                                       unsigned long addr, void *arg);
+};
+
 /*
  * Called by migrate.c to remove migration ptes, but might be used more later.
  */
-int rmap_walk(struct page *page, int (*rmap_one)(struct page *,
-               struct vm_area_struct *, unsigned long, void *), void *arg);
+int rmap_walk(struct page *page, struct rmap_walk_control *rwc);
 
 #else  /* !CONFIG_MMU */
 

diff --git a/mm/ksm.c b/mm/ksm.c
index 175fff79dc95749f6607aaa70976ebff09193397..c3035fee808042dafe5cf4e022183245c22a80b4 100644 (file)
--- a/mm/ksm.c
+++ b/mm/ksm.c
@@ -1997,8 +1997,7 @@ out:
 }
 
 #ifdef CONFIG_MIGRATION
-int rmap_walk_ksm(struct page *page, int (*rmap_one)(struct page *,
-                 struct vm_area_struct *, unsigned long, void *), void *arg)
+int rmap_walk_ksm(struct page *page, struct rmap_walk_control *rwc)
 {
        struct stable_node *stable_node;
        struct rmap_item *rmap_item;
@@ -2033,7 +2032,8 @@ again:
                        if ((rmap_item->mm == vma->vm_mm) == search_new_forks)
                                continue;
 
-                       ret = rmap_one(page, vma, rmap_item->address, arg);
+                       ret = rwc->rmap_one(page, vma,
+                                       rmap_item->address, rwc->arg);
                        if (ret != SWAP_AGAIN) {
                                anon_vma_unlock_read(anon_vma);
                                goto out;

diff --git a/mm/migrate.c b/mm/migrate.c
index 9194375b230729fead356e8dd3c8f6bb951415ab..11d89dc0574c20880cd31599cca58f891ead8089 100644 (file)
--- a/mm/migrate.c
+++ b/mm/migrate.c
@@ -199,7 +199,12 @@ out:
  */
 static void remove_migration_ptes(struct page *old, struct page *new)
 {
-       rmap_walk(new, remove_migration_pte, old);
+       struct rmap_walk_control rwc = {
+               .rmap_one = remove_migration_pte,
+               .arg = old,
+       };
+
+       rmap_walk(new, &rwc);
 }
 
 /*

diff --git a/mm/rmap.c b/mm/rmap.c
index 5a79bf585e2795324eb44228e134f4d34ba62a43..f8f10ad5d3594557a61173059302077832812b71 100644 (file)
--- a/mm/rmap.c
+++ b/mm/rmap.c
@@ -1706,8 +1706,7 @@ static struct anon_vma *rmap_walk_anon_lock(struct page *page)
  * rmap_walk() and its helpers rmap_walk_anon() and rmap_walk_file():
  * Called by migrate.c to remove migration ptes, but might be used more later.
  */
-static int rmap_walk_anon(struct page *page, int (*rmap_one)(struct page *,
-               struct vm_area_struct *, unsigned long, void *), void *arg)
+static int rmap_walk_anon(struct page *page, struct rmap_walk_control *rwc)
 {
        struct anon_vma *anon_vma;
        pgoff_t pgoff = page->index << (PAGE_CACHE_SHIFT - PAGE_SHIFT);
@@ -1721,7 +1720,7 @@ static int rmap_walk_anon(struct page *page, int (*rmap_one)(struct page *,
        anon_vma_interval_tree_foreach(avc, &anon_vma->rb_root, pgoff, pgoff) {
                struct vm_area_struct *vma = avc->vma;
                unsigned long address = vma_address(page, vma);
-               ret = rmap_one(page, vma, address, arg);
+               ret = rwc->rmap_one(page, vma, address, rwc->arg);
                if (ret != SWAP_AGAIN)
                        break;
        }
@@ -1729,8 +1728,7 @@ static int rmap_walk_anon(struct page *page, int (*rmap_one)(struct page *,
        return ret;
 }
 
-static int rmap_walk_file(struct page *page, int (*rmap_one)(struct page *,
-               struct vm_area_struct *, unsigned long, void *), void *arg)
+static int rmap_walk_file(struct page *page, struct rmap_walk_control *rwc)
 {
        struct address_space *mapping = page->mapping;
        pgoff_t pgoff = page->index << compound_order(page);
@@ -1742,7 +1740,7 @@ static int rmap_walk_file(struct page *page, int (*rmap_one)(struct page *,
        mutex_lock(&mapping->i_mmap_mutex);
        vma_interval_tree_foreach(vma, &mapping->i_mmap, pgoff, pgoff) {
                unsigned long address = vma_address(page, vma);
-               ret = rmap_one(page, vma, address, arg);
+               ret = rwc->rmap_one(page, vma, address, rwc->arg);
                if (ret != SWAP_AGAIN)
                        break;
        }
@@ -1755,17 +1753,16 @@ static int rmap_walk_file(struct page *page, int (*rmap_one)(struct page *,
        return ret;
 }
 
-int rmap_walk(struct page *page, int (*rmap_one)(struct page *,
-               struct vm_area_struct *, unsigned long, void *), void *arg)
+int rmap_walk(struct page *page, struct rmap_walk_control *rwc)
 {
        VM_BUG_ON(!PageLocked(page));
 
        if (unlikely(PageKsm(page)))
-               return rmap_walk_ksm(page, rmap_one, arg);
+               return rmap_walk_ksm(page, rwc);
        else if (PageAnon(page))
-               return rmap_walk_anon(page, rmap_one, arg);
+               return rmap_walk_anon(page, rwc);
        else
-               return rmap_walk_file(page, rmap_one, arg);
+               return rmap_walk_file(page, rwc);
 }
 #endif /* CONFIG_MIGRATION */