The patch titled
memcg: helper function for relcaim from shmem.
has been added to the -mm tree. Its filename is
memcg-helper-function-for-relcaim-from-shmem.patch
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out what to do about this
The current -mm tree may be found at http://userweb.kernel.org/~akpm/mmotm/
------------------------------------------------------
Subject: memcg: helper function for relcaim from shmem.
From: KAMEZAWA Hiroyuki <kamezawa.hiroyu@xxxxxxxxxxxxxx>
A new call, mem_cgroup_shrink_usage() is added for shmem handling and
relacing non-standard usage of mem_cgroup_charge/uncharge.
Now, shmem calls mem_cgroup_charge() just for reclaim some pages from
mem_cgroup. In general, shmem is used by some process group and not for
global resource (like file caches). So, it's reasonable to reclaim pages
from mem_cgroup where shmem is mainly used.
Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@xxxxxxxxxxxxxx>
Cc: Balbir Singh <balbir@xxxxxxxxxx>
Cc: "Eric W. Biederman" <ebiederm@xxxxxxxxxxxx>
Cc: Pavel Emelyanov <xemul@xxxxxxxxxx>
Cc: Li Zefan <lizf@xxxxxxxxxxxxxx>
Cc: Hugh Dickins <hugh@xxxxxxxxxxx>
Cc: YAMAMOTO Takashi <yamamoto@xxxxxxxxxxxxx>
Cc: Paul Menage <menage@xxxxxxxxxx>
Cc: David Rientjes <rientjes@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
include/linux/memcontrol.h | 7 +++++++
mm/memcontrol.c | 25 +++++++++++++++++++++++++
mm/shmem.c | 5 ++---
3 files changed, 34 insertions(+), 3 deletions(-)
diff -puN include/linux/memcontrol.h~memcg-helper-function-for-relcaim-from-shmem include/linux/memcontrol.h
--- a/include/linux/memcontrol.h~memcg-helper-function-for-relcaim-from-shmem
+++ a/include/linux/memcontrol.h
@@ -37,6 +37,8 @@ extern int mem_cgroup_cache_charge(struc
extern void mem_cgroup_uncharge_page(struct page *page);
extern void mem_cgroup_uncharge_cache_page(struct page *page);
extern void mem_cgroup_move_lists(struct page *page, bool active);
+extern int mem_cgroup_shrink_usage(struct mm_struct *mm, gfp_t gfp_mask);
+
extern unsigned long mem_cgroup_isolate_pages(unsigned long nr_to_scan,
struct list_head *dst,
unsigned long *scanned, int order,
@@ -102,6 +104,11 @@ static inline void mem_cgroup_uncharge_c
{
}
+static inline int mem_cgroup_shrink_usage(struct mm_struct *mm, gfp_t gfp_mask)
+{
+ return 0;
+}
+
static inline void mem_cgroup_move_lists(struct page *page, bool active)
{
}
diff -puN mm/memcontrol.c~memcg-helper-function-for-relcaim-from-shmem mm/memcontrol.c
--- a/mm/memcontrol.c~memcg-helper-function-for-relcaim-from-shmem
+++ a/mm/memcontrol.c
@@ -770,6 +770,31 @@ void mem_cgroup_end_migration(struct pag
}
/*
+ * A call to try to shrink memory usage under specified resource controller.
+ * 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)
+{
+ struct mem_cgroup *mem;
+ int progress = 0;
+ int retry = MEM_CGROUP_RECLAIM_RETRIES;
+
+ rcu_read_lock();
+ mem = mem_cgroup_from_task(rcu_dereference(mm->owner));
+ css_get(&mem->css);
+ rcu_read_unlock();
+
+ do {
+ progress = try_to_free_mem_cgroup_pages(mem, gfp_mask);
+ } while (!progress && --retry);
+
+ if (!retry)
+ return -ENOMEM;
+ return 0;
+}
+
+/*
* This routine traverse page_cgroup in given list and drop them all.
* *And* this routine doesn't reclaim page itself, just removes page_cgroup.
*/
diff -puN mm/shmem.c~memcg-helper-function-for-relcaim-from-shmem mm/shmem.c
--- a/mm/shmem.c~memcg-helper-function-for-relcaim-from-shmem
+++ a/mm/shmem.c
@@ -1321,13 +1321,12 @@ repeat:
unlock_page(swappage);
if (error == -ENOMEM) {
/* allow reclaim from this memory cgroup */
- error = mem_cgroup_cache_charge(swappage,
- current->mm, gfp & ~__GFP_HIGHMEM);
+ error = mem_cgroup_shrink_usage(current->mm,
+ gfp & ~__GFP_HIGHMEM);
if (error) {
page_cache_release(swappage);
goto failed;
}
- mem_cgroup_uncharge_cache_page(swappage);
}
page_cache_release(swappage);
goto repeat;
_
Patches currently in -mm which might be from kamezawa.hiroyu@xxxxxxxxxxxxxx are
origin.patch
memory-hotplug-memmap_init_zone-called-twice.patch
memory_hotplug-check-for-walk_memory_resource-failure-in-online_pages.patch
memory_hotplug-always-initialize-pageblock-bitmap.patch
mark-res_counter_charge_locked-with-__must_check.patch
memcg-make-global-var-read_mostly.patch
memcg-avoid-unnecessary-initialization.patch
memcg-better-migration-handling.patch
memcg-remove-refcnt-from-page_cgroup.patch
memcg-handle-swap-cache.patch
memcg-helper-function-for-relcaim-from-shmem.patch
memcg-add-hints-for-branch.patch
memcg-remove-a-redundant-check.patch
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