The patch titled
memcg: fix shmem's swap accounting
has been removed from the -mm tree. Its filename was
memcg-fix-shmems-swap-accounting.patch
This patch was dropped because it was merged into mainline or a subsystem tree
The current -mm tree may be found at http://userweb.kernel.org/~akpm/mmotm/
------------------------------------------------------
Subject: memcg: fix shmem's swap accounting
From: KAMEZAWA Hiroyuki <kamezawa.hiroyu@xxxxxxxxxxxxxx>
Now, you can see following even when swap accounting is enabled.
1. Create Group 01, and 02.
2. allocate a "file" on tmpfs by a task under 01.
3. swap out the "file" (by memory pressure)
4. Read "file" from a task in group 02.
5. the charge of "file" is moved to group 02.
This is not ideal behavior. This is because SwapCache which was loaded
by read-ahead is not taken into account..
This is a patch to fix shmem's swapcache behavior.
- remove mem_cgroup_cache_charge_swapin().
- Add SwapCache handler routine to mem_cgroup_cache_charge().
By this, shmem's file cache is charged at add_to_page_cache()
with GFP_NOWAIT.
- pass the page of swapcache to shrink_mem_cgroup.
Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@xxxxxxxxxxxxxx>
Cc: Daisuke Nishimura <nishimura@xxxxxxxxxxxxxxxxx>
Cc: Balbir Singh <balbir@xxxxxxxxxx>
Cc: Paul Menage <menage@xxxxxxxxxx>
Cc: Li Zefan <lizf@xxxxxxxxxxxxxx>
Cc: Hugh Dickins <hugh@xxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
include/linux/memcontrol.h | 6 +
include/linux/swap.h | 8 --
mm/memcontrol.c | 134 +++++++++++++++--------------------
mm/shmem.c | 30 +++----
4 files changed, 76 insertions(+), 102 deletions(-)
diff -puN include/linux/memcontrol.h~memcg-fix-shmems-swap-accounting include/linux/memcontrol.h
--- a/include/linux/memcontrol.h~memcg-fix-shmems-swap-accounting
+++ a/include/linux/memcontrol.h
@@ -56,7 +56,8 @@ extern void mem_cgroup_move_lists(struct
enum lru_list from, enum lru_list to);
extern void mem_cgroup_uncharge_page(struct page *page);
extern void mem_cgroup_uncharge_cache_page(struct page *page);
-extern int mem_cgroup_shrink_usage(struct mm_struct *mm, gfp_t gfp_mask);
+extern int mem_cgroup_shrink_usage(struct page *page,
+ struct mm_struct *mm, gfp_t gfp_mask);
extern unsigned long mem_cgroup_isolate_pages(unsigned long nr_to_scan,
struct list_head *dst,
@@ -155,7 +156,8 @@ static inline void mem_cgroup_uncharge_c
{
}
-static inline int mem_cgroup_shrink_usage(struct mm_struct *mm, gfp_t gfp_mask)
+static inline int mem_cgroup_shrink_usage(struct page *page,
+ struct mm_struct *mm, gfp_t gfp_mask)
{
return 0;
}
diff -puN include/linux/swap.h~memcg-fix-shmems-swap-accounting include/linux/swap.h
--- a/include/linux/swap.h~memcg-fix-shmems-swap-accounting
+++ a/include/linux/swap.h
@@ -335,16 +335,8 @@ static inline void disable_swap_token(vo
}
#ifdef CONFIG_CGROUP_MEM_RES_CTLR
-extern int mem_cgroup_cache_charge_swapin(struct page *page,
- struct mm_struct *mm, gfp_t mask, bool locked);
extern void mem_cgroup_uncharge_swapcache(struct page *page, swp_entry_t ent);
#else
-static inline
-int mem_cgroup_cache_charge_swapin(struct page *page,
- struct mm_struct *mm, gfp_t mask, bool locked)
-{
- return 0;
-}
static inline void
mem_cgroup_uncharge_swapcache(struct page *page, swp_entry_t ent)
{
diff -puN mm/memcontrol.c~memcg-fix-shmems-swap-accounting mm/memcontrol.c
--- a/mm/memcontrol.c~memcg-fix-shmems-swap-accounting
+++ a/mm/memcontrol.c
@@ -893,6 +893,23 @@ nomem:
return -ENOMEM;
}
+static struct mem_cgroup *try_get_mem_cgroup_from_swapcache(struct page *page)
+{
+ struct mem_cgroup *mem;
+ swp_entry_t ent;
+
+ if (!PageSwapCache(page))
+ return NULL;
+
+ ent.val = page_private(page);
+ mem = lookup_swap_cgroup(ent);
+ if (!mem)
+ return NULL;
+ if (!css_tryget(&mem->css))
+ return NULL;
+ return mem;
+}
+
/*
* commit a charge got by __mem_cgroup_try_charge() and makes page_cgroup to be
* USED state. If already USED, uncharge and return.
@@ -1084,6 +1101,9 @@ int mem_cgroup_newpage_charge(struct pag
int mem_cgroup_cache_charge(struct page *page, struct mm_struct *mm,
gfp_t gfp_mask)
{
+ struct mem_cgroup *mem = NULL;
+ int ret;
+
if (mem_cgroup_disabled())
return 0;
if (PageCompound(page))
@@ -1096,6 +1116,8 @@ int mem_cgroup_cache_charge(struct page
* For GFP_NOWAIT case, the page may be pre-charged before calling
* add_to_page_cache(). (See shmem.c) check it here and avoid to call
* charge twice. (It works but has to pay a bit larger cost.)
+ * And when the page is SwapCache, it should take swap information
+ * into account. This is under lock_page() now.
*/
if (!(gfp_mask & __GFP_WAIT)) {
struct page_cgroup *pc;
@@ -1112,15 +1134,40 @@ int mem_cgroup_cache_charge(struct page
unlock_page_cgroup(pc);
}
- if (unlikely(!mm))
+ if (do_swap_account && PageSwapCache(page)) {
+ mem = try_get_mem_cgroup_from_swapcache(page);
+ if (mem)
+ mm = NULL;
+ else
+ mem = NULL;
+ /* SwapCache may be still linked to LRU now. */
+ mem_cgroup_lru_del_before_commit_swapcache(page);
+ }
+
+ if (unlikely(!mm && !mem))
mm = &init_mm;
if (page_is_file_cache(page))
return mem_cgroup_charge_common(page, mm, gfp_mask,
MEM_CGROUP_CHARGE_TYPE_CACHE, NULL);
- else
- return mem_cgroup_charge_common(page, mm, gfp_mask,
- MEM_CGROUP_CHARGE_TYPE_SHMEM, NULL);
+
+ ret = mem_cgroup_charge_common(page, mm, gfp_mask,
+ MEM_CGROUP_CHARGE_TYPE_SHMEM, mem);
+ if (mem)
+ css_put(&mem->css);
+ if (PageSwapCache(page))
+ mem_cgroup_lru_add_after_commit_swapcache(page);
+
+ if (do_swap_account && !ret && PageSwapCache(page)) {
+ swp_entry_t ent = {.val = page_private(page)};
+ /* avoid double counting */
+ mem = swap_cgroup_record(ent, NULL);
+ if (mem) {
+ res_counter_uncharge(&mem->memsw, PAGE_SIZE);
+ mem_cgroup_put(mem);
+ }
+ }
+ return ret;
}
/*
@@ -1134,7 +1181,6 @@ int mem_cgroup_try_charge_swapin(struct
gfp_t mask, struct mem_cgroup **ptr)
{
struct mem_cgroup *mem;
- swp_entry_t ent;
int ret;
if (mem_cgroup_disabled())
@@ -1142,7 +1188,6 @@ int mem_cgroup_try_charge_swapin(struct
if (!do_swap_account)
goto charge_cur_mm;
-
/*
* A racing thread's fault, or swapoff, may have already updated
* the pte, and even removed page from swap cache: return success
@@ -1150,14 +1195,9 @@ int mem_cgroup_try_charge_swapin(struct
*/
if (!PageSwapCache(page))
return 0;
-
- ent.val = page_private(page);
-
- mem = lookup_swap_cgroup(ent);
+ mem = try_get_mem_cgroup_from_swapcache(page);
if (!mem)
goto charge_cur_mm;
- if (!css_tryget(&mem->css))
- goto charge_cur_mm;
*ptr = mem;
ret = __mem_cgroup_try_charge(NULL, mask, ptr, true);
/* drop extra refcnt from tryget */
@@ -1169,62 +1209,6 @@ charge_cur_mm:
return __mem_cgroup_try_charge(mm, mask, ptr, true);
}
-#ifdef CONFIG_SWAP
-
-int mem_cgroup_cache_charge_swapin(struct page *page,
- struct mm_struct *mm, gfp_t mask, bool locked)
-{
- int ret = 0;
-
- if (mem_cgroup_disabled())
- return 0;
- if (unlikely(!mm))
- mm = &init_mm;
- if (!locked)
- lock_page(page);
- /*
- * If not locked, the page can be dropped from SwapCache until
- * we reach here.
- */
- if (PageSwapCache(page)) {
- struct mem_cgroup *mem = NULL;
- swp_entry_t ent;
-
- ent.val = page_private(page);
- if (do_swap_account) {
- mem = lookup_swap_cgroup(ent);
- if (mem) {
- if (css_tryget(&mem->css))
- mm = NULL; /* charge to recorded */
- else
- mem = NULL; /* charge to current */
- }
- }
- /* SwapCache may be still linked to LRU now. */
- mem_cgroup_lru_del_before_commit_swapcache(page);
- ret = mem_cgroup_charge_common(page, mm, mask,
- MEM_CGROUP_CHARGE_TYPE_SHMEM, mem);
- mem_cgroup_lru_add_after_commit_swapcache(page);
- /* drop extra refcnt from tryget */
- if (mem)
- css_put(&mem->css);
-
- if (!ret && do_swap_account) {
- /* avoid double counting */
- mem = swap_cgroup_record(ent, NULL);
- if (mem) {
- res_counter_uncharge(&mem->memsw, PAGE_SIZE);
- mem_cgroup_put(mem);
- }
- }
- }
- if (!locked)
- unlock_page(page);
-
- return ret;
-}
-#endif
-
void mem_cgroup_commit_charge_swapin(struct page *page, struct mem_cgroup *ptr)
{
struct page_cgroup *pc;
@@ -1486,18 +1470,20 @@ void mem_cgroup_end_migration(struct mem
* This is typically used for page reclaiming for shmem for reducing side
* effect of page allocation from shmem, which is used by some mem_cgroup.
*/
-int mem_cgroup_shrink_usage(struct mm_struct *mm, gfp_t gfp_mask)
+int mem_cgroup_shrink_usage(struct page *page,
+ struct mm_struct *mm,
+ gfp_t gfp_mask)
{
- struct mem_cgroup *mem;
+ struct mem_cgroup *mem = NULL;
int progress = 0;
int retry = MEM_CGROUP_RECLAIM_RETRIES;
if (mem_cgroup_disabled())
return 0;
- if (!mm)
- return 0;
-
- mem = try_get_mem_cgroup_from_mm(mm);
+ if (page)
+ mem = try_get_mem_cgroup_from_swapcache(page);
+ if (!mem && mm)
+ mem = try_get_mem_cgroup_from_mm(mm);
if (unlikely(!mem))
return 0;
diff -puN mm/shmem.c~memcg-fix-shmems-swap-accounting mm/shmem.c
--- a/mm/shmem.c~memcg-fix-shmems-swap-accounting
+++ a/mm/shmem.c
@@ -929,11 +929,11 @@ found:
if (!inode)
goto out;
/*
- * Charge page using GFP_HIGHUSER_MOVABLE while we can wait.
- * charged back to the user(not to caller) when swap account is used.
+ * Charge page using GFP_KERNEL while we can wait.
+ * Charged back to the user(not to caller) when swap account is used.
+ * add_to_page_cache() will be called with GFP_NOWAIT.
*/
- error = mem_cgroup_cache_charge_swapin(page, current->mm, GFP_KERNEL,
- true);
+ error = mem_cgroup_cache_charge(page, current->mm, GFP_KERNEL);
if (error)
goto out;
error = radix_tree_preload(GFP_KERNEL);
@@ -1270,16 +1270,6 @@ repeat:
goto repeat;
}
wait_on_page_locked(swappage);
- /*
- * We want to avoid charge at add_to_page_cache().
- * charge against this swap cache here.
- */
- if (mem_cgroup_cache_charge_swapin(swappage,
- current->mm, gfp & GFP_RECLAIM_MASK, false)) {
- page_cache_release(swappage);
- error = -ENOMEM;
- goto failed;
- }
page_cache_release(swappage);
goto repeat;
}
@@ -1334,15 +1324,19 @@ repeat:
} else {
shmem_swp_unmap(entry);
spin_unlock(&info->lock);
- unlock_page(swappage);
- page_cache_release(swappage);
if (error == -ENOMEM) {
/* allow reclaim from this memory cgroup */
- error = mem_cgroup_shrink_usage(current->mm,
+ error = mem_cgroup_shrink_usage(swappage,
+ current->mm,
gfp);
- if (error)
+ if (error) {
+ unlock_page(swappage);
+ page_cache_release(swappage);
goto failed;
+ }
}
+ unlock_page(swappage);
+ page_cache_release(swappage);
goto repeat;
}
} else if (sgp == SGP_READ && !filepage) {
_
Patches currently in -mm which might be from kamezawa.hiroyu@xxxxxxxxxxxxxx are
origin.patch
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