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authorKAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>2008-07-25 01:47:15 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2008-07-25 10:53:37 -0700
commitc9b0ed51483cc2fc42bb801b6675c4231b0e4634 (patch)
tree1d322b4bfcaad3296752f6efcab918d1b13b50a3
parent69029cd550284e32de13d6dd2f77b723c8a0e444 (diff)
downloadlinux-2.6.34-ux500-c9b0ed51483cc2fc42bb801b6675c4231b0e4634.tar.gz
memcg: helper function for relcaim from shmem.
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. [hugh@veritas.com: shmem_getpage release page sooner] [hugh@veritas.com: mem_cgroup_shrink_usage css_put] Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Balbir Singh <balbir@in.ibm.com> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Pavel Emelyanov <xemul@openvz.org> Cc: Li Zefan <lizf@cn.fujitsu.com> Cc: YAMAMOTO Takashi <yamamoto@valinux.co.jp> Cc: Paul Menage <menage@google.com> Cc: David Rientjes <rientjes@google.com> Signed-off-by: Hugh Dickins <hugh@veritas.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-rw-r--r--include/linux/memcontrol.h7
-rw-r--r--mm/memcontrol.c26
-rw-r--r--mm/shmem.c11
3 files changed, 37 insertions, 7 deletions
diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h
index b4980b8f048..fdf3967e139 100644
--- a/include/linux/memcontrol.h
+++ b/include/linux/memcontrol.h
@@ -37,6 +37,8 @@ extern int mem_cgroup_cache_charge(struct page *page, struct mm_struct *mm,
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_cache_page(struct page *page)
{
}
+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 --git a/mm/memcontrol.c b/mm/memcontrol.c
index a61706193c3..f46b8615de6 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -781,6 +781,32 @@ void mem_cgroup_end_migration(struct page *newpage)
}
/*
+ * 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);
+
+ css_put(&mem->css);
+ 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 --git a/mm/shmem.c b/mm/shmem.c
index d58305e8a48..f92fea94d03 100644
--- a/mm/shmem.c
+++ b/mm/shmem.c
@@ -1315,17 +1315,14 @@ repeat:
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_cache_charge(swappage,
- current->mm, gfp & ~__GFP_HIGHMEM);
- if (error) {
- page_cache_release(swappage);
+ error = mem_cgroup_shrink_usage(current->mm,
+ gfp);
+ if (error)
goto failed;
- }
- mem_cgroup_uncharge_cache_page(swappage);
}
- page_cache_release(swappage);
goto repeat;
}
} else if (sgp == SGP_READ && !filepage) {