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/mm/memcontrol.c b/mm/memcontrol.c
index c0111cb..a44494f 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -4531,9 +4531,8 @@
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 @@
}
/**
- * 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 @@
*
* 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 @@
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);
}
/*