mm: rename mem_cgroup_migrate to mem_cgroup_replace_page

After v4.3's commit 0610c25daa3e ("memcg: fix dirty page migration")
mem_cgroup_migrate() doesn't have much to offer in page migration: convert
migrate_misplaced_transhuge_page() to set_page_memcg() instead.

Then rename mem_cgroup_migrate() to mem_cgroup_replace_page(), since its
remaining callers are replace_page_cache_page() and shmem_replace_page():
both of whom passed lrucare true, so just eliminate that argument.

Signed-off-by: Hugh Dickins <hughd@google.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Sasha Levin <sasha.levin@oracle.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h
index 998311e0c70ce3ef32b4a53794f9ab44ae2e104d..c06c70b4404ea5d66503e9fb5f5fb9662c577de1 100644 (file)
--- a/include/linux/memcontrol.h
+++ b/include/linux/memcontrol.h
@@ -297,8 +297,7 @@ void mem_cgroup_cancel_charge(struct page *page, struct mem_cgroup *memcg);
 void mem_cgroup_uncharge(struct page *page);
 void mem_cgroup_uncharge_list(struct list_head *page_list);
 
-void mem_cgroup_migrate(struct page *oldpage, struct page *newpage,
-                       bool lrucare);
+void mem_cgroup_replace_page(struct page *oldpage, struct page *newpage);
 
 struct lruvec *mem_cgroup_zone_lruvec(struct zone *, struct mem_cgroup *);
 struct lruvec *mem_cgroup_page_lruvec(struct page *, struct zone *);
@@ -537,9 +536,7 @@ static inline void mem_cgroup_uncharge_list(struct list_head *page_list)
 {
 }
 
-static inline void mem_cgroup_migrate(struct page *oldpage,
-                                     struct page *newpage,
-                                     bool lrucare)
+static inline void mem_cgroup_replace_page(struct page *old, struct page *new)
 {
 }
 

diff --git a/mm/filemap.c b/mm/filemap.c
index 884766da11655afb1bf54d176ed32da732aa3f3d..58e04e26f9965d5ddb8c35fc3770349493b62eab 100644 (file)
--- a/mm/filemap.c
+++ b/mm/filemap.c
@@ -551,7 +551,7 @@ int replace_page_cache_page(struct page *old, struct page *new, gfp_t gfp_mask)
                        __inc_zone_page_state(new, NR_SHMEM);
                spin_unlock_irqrestore(&mapping->tree_lock, flags);
                mem_cgroup_end_page_stat(memcg);
-               mem_cgroup_migrate(old, new, true);
+               mem_cgroup_replace_page(old, new);
                radix_tree_preload_end();
                if (freepage)
                        freepage(old);

diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index c0111cb667b583523753012e19d2b2ba321d1a7b..a44494f3a96543ea344897290dbb8ae8d7915e39 100644 (file)
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -4531,9 +4531,8 @@ static int mem_cgroup_move_account(struct page *page,
                goto out;
 
        /*
-        * Prevent mem_cgroup_migrate() from looking at page->mem_cgroup
-        * of its source page while we change it: page migration takes
-        * both pages off the LRU, but page cache replacement doesn't.
+        * Prevent mem_cgroup_replace_page() from looking at
+        * page->mem_cgroup of its source page while we change it.
         */
        if (!trylock_page(page))
                goto out;
@@ -5495,7 +5494,7 @@ void mem_cgroup_uncharge_list(struct list_head *page_list)
 }
 
 /**
- * mem_cgroup_migrate - migrate a charge to another page
+ * mem_cgroup_replace_page - migrate a charge to another page
  * @oldpage: currently charged page
  * @newpage: page to transfer the charge to
  * @lrucare: either or both pages might be on the LRU already
@@ -5504,16 +5503,13 @@ void mem_cgroup_uncharge_list(struct list_head *page_list)
  *
  * Both pages must be locked, @newpage->mapping must be set up.
  */
-void mem_cgroup_migrate(struct page *oldpage, struct page *newpage,
-                       bool lrucare)
+void mem_cgroup_replace_page(struct page *oldpage, struct page *newpage)
 {
        struct mem_cgroup *memcg;
        int isolated;
 
        VM_BUG_ON_PAGE(!PageLocked(oldpage), oldpage);
        VM_BUG_ON_PAGE(!PageLocked(newpage), newpage);
-       VM_BUG_ON_PAGE(!lrucare && PageLRU(oldpage), oldpage);
-       VM_BUG_ON_PAGE(!lrucare && PageLRU(newpage), newpage);
        VM_BUG_ON_PAGE(PageAnon(oldpage) != PageAnon(newpage), newpage);
        VM_BUG_ON_PAGE(PageTransHuge(oldpage) != PageTransHuge(newpage),
                       newpage);
@@ -5525,25 +5521,16 @@ void mem_cgroup_migrate(struct page *oldpage, struct page *newpage,
        if (newpage->mem_cgroup)
                return;
 
-       /*
-        * Swapcache readahead pages can get migrated before being
-        * charged, and migration from compaction can happen to an
-        * uncharged page when the PFN walker finds a page that
-        * reclaim just put back on the LRU but has not released yet.
-        */
+       /* Swapcache readahead pages can get replaced before being charged */
        memcg = oldpage->mem_cgroup;
        if (!memcg)
                return;
 
-       if (lrucare)
-               lock_page_lru(oldpage, &isolated);
-
+       lock_page_lru(oldpage, &isolated);
        oldpage->mem_cgroup = NULL;
+       unlock_page_lru(oldpage, isolated);
 
-       if (lrucare)
-               unlock_page_lru(oldpage, isolated);
-
-       commit_charge(newpage, memcg, lrucare);
+       commit_charge(newpage, memcg, true);
 }
 
 /*

diff --git a/mm/migrate.c b/mm/migrate.c
index ed72c499df8ac33cf48c19bb2e4822f3f6f006c3..836e4108eaef5dd57da66463bf873efd43ba374e 100644 (file)
--- a/mm/migrate.c
+++ b/mm/migrate.c
@@ -30,7 +30,6 @@
 #include <linux/mempolicy.h>
 #include <linux/vmalloc.h>
 #include <linux/security.h>
-#include <linux/memcontrol.h>
 #include <linux/syscalls.h>
 #include <linux/hugetlb.h>
 #include <linux/hugetlb_cgroup.h>
@@ -1831,8 +1830,8 @@ fail_putback:
        }
 
        mlock_migrate_page(new_page, page);
-       mem_cgroup_migrate(page, new_page, false);
-
+       set_page_memcg(new_page, page_memcg(page));
+       set_page_memcg(page, NULL);
        page_remove_rmap(page);
 
        spin_unlock(ptl);

diff --git a/mm/shmem.c b/mm/shmem.c
index 48ce82926d931bef026baf16a971add9d00c45fd..6529226b38140fcc93aaa5a5f49f7e5877607016 100644 (file)
--- a/mm/shmem.c
+++ b/mm/shmem.c
@@ -1023,7 +1023,7 @@ static int shmem_replace_page(struct page **pagep, gfp_t gfp,
                 */
                oldpage = newpage;
        } else {
-               mem_cgroup_migrate(oldpage, newpage, true);
+               mem_cgroup_replace_page(oldpage, newpage);
                lru_cache_add_anon(newpage);
                *pagep = newpage;
        }