Add an interface to set limit. This is necessary to memory resource controller
because it shrinks usage at set limit.
(*) Other controller may not need this interface to shrink usage because
shrinking is not necessary or impossible in it.
Changelog:
- fixed white space bug.
Acked-by: Balbir Singh <[email protected]>
Signed-off-by: KAMEZAWA Hiroyuki <[email protected]>
include/linux/res_counter.h | 15 +++++++++++++++
1 file changed, 15 insertions(+)
Index: test-2.6.26-rc8-mm1/include/linux/res_counter.h
===================================================================
--- test-2.6.26-rc8-mm1.orig/include/linux/res_counter.h
+++ test-2.6.26-rc8-mm1/include/linux/res_counter.h
@@ -176,4 +176,19 @@ static inline bool res_counter_can_add(s
return ret;
}
+static inline int res_counter_set_limit(struct res_counter *cnt,
+ unsigned long long limit)
+{
+ unsigned long flags;
+ int ret = -EBUSY;
+
+ spin_lock_irqsave(&cnt->lock, flags);
+ if (cnt->usage < limit) {
+ cnt->limit = limit;
+ ret = 0;
+ }
+ spin_unlock_irqrestore(&cnt->lock, flags);
+ return ret;
+}
+
#endif
Shrinking memory usage at limit change.
Changelog: v1 -> v2
- adjusted to be based on write_string() patch set
fixed pointed out styles (below)
- removed backword goto.
- removed unneccesary cond_resched().
Acked-by: Balbir Singh <[email protected]>
Signed-off-by: KAMEZAWA Hiroyuki <[email protected]>
Documentation/controllers/memory.txt | 3 --
mm/memcontrol.c | 43 +++++++++++++++++++++++++++++++----
2 files changed, 40 insertions(+), 6 deletions(-)
Index: test-2.6.26-rc8-mm1/mm/memcontrol.c
===================================================================
--- test-2.6.26-rc8-mm1.orig/mm/memcontrol.c
+++ test-2.6.26-rc8-mm1/mm/memcontrol.c
@@ -836,6 +836,26 @@ int mem_cgroup_shrink_usage(struct mm_st
return 0;
}
+int mem_cgroup_resize_limit(struct mem_cgroup *memcg, unsigned long long val)
+{
+
+ int retry_count = MEM_CGROUP_RECLAIM_RETRIES;
+ int progress;
+ int ret = 0;
+
+ while (res_counter_set_limit(&memcg->res, val)) {
+ if (!retry_count) {
+ ret = -EBUSY;
+ break;
+ }
+ progress = try_to_free_mem_cgroup_pages(memcg, GFP_KERNEL);
+ if (!progress)
+ retry_count--;
+ }
+ return ret;
+}
+
+
/*
* This routine traverse page_cgroup in given list and drop them all.
* *And* this routine doesn't reclaim page itself, just removes page_cgroup.
@@ -916,13 +936,29 @@ static u64 mem_cgroup_read(struct cgroup
return res_counter_read_u64(&mem_cgroup_from_cont(cont)->res,
cft->private);
}
-
+/*
+ * The user of this function is...
+ * RES_LIMIT.
+ */
static int mem_cgroup_write(struct cgroup *cont, struct cftype *cft,
const char *buffer)
{
- return res_counter_write(&mem_cgroup_from_cont(cont)->res,
- cft->private, buffer,
- res_counter_memparse_write_strategy);
+ struct mem_cgroup *memcg = mem_cgroup_from_cont(cont);
+ unsigned long long val;
+ int ret;
+
+ switch (cft->private) {
+ case RES_LIMIT:
+ /* This function does all necessary parse...reuse it */
+ ret = res_counter_memparse_write_strategy(buffer, &val);
+ if (!ret)
+ ret = mem_cgroup_resize_limit(memcg, val);
+ break;
+ default:
+ ret = -EINVAL; /* should be BUG() ? */
+ break;
+ }
+ return ret;
}
static int mem_cgroup_reset(struct cgroup *cont, unsigned int event)
Index: test-2.6.26-rc8-mm1/Documentation/controllers/memory.txt
===================================================================
--- test-2.6.26-rc8-mm1.orig/Documentation/controllers/memory.txt
+++ test-2.6.26-rc8-mm1/Documentation/controllers/memory.txt
@@ -242,8 +242,7 @@ rmdir() if there are no tasks.
1. Add support for accounting huge pages (as a separate controller)
2. Make per-cgroup scanner reclaim not-shared pages first
3. Teach controller to account for shared-pages
-4. Start reclamation when the limit is lowered
-5. Start reclamation in the background when the limit is
+4. Start reclamation in the background when the limit is
not yet hit but the usage is getting closer
Summary
KAMEZAWA Hiroyuki wrote:
> Shrinking memory usage at limit change.
>
> Changelog: v1 -> v2
> - adjusted to be based on write_string() patch set
> fixed pointed out styles (below)
> - removed backword goto.
> - removed unneccesary cond_resched().
>
> Acked-by: Balbir Singh <[email protected]>
Acked-by: Pavel Emelyanov <[email protected]>
> Signed-off-by: KAMEZAWA Hiroyuki <[email protected]>
KAMEZAWA Hiroyuki wrote:
> Add an interface to set limit. This is necessary to memory resource controller
> because it shrinks usage at set limit.
>
> (*) Other controller may not need this interface to shrink usage because
> shrinking is not necessary or impossible in it.
>
> Changelog:
> - fixed white space bug.
>
> Acked-by: Balbir Singh <[email protected]>
Acked-by: Pavel Emelyanov <[email protected]>
> Signed-off-by: KAMEZAWA Hiroyuki <[email protected]>
>
>
> include/linux/res_counter.h | 15 +++++++++++++++
> 1 file changed, 15 insertions(+)
>
> Index: test-2.6.26-rc8-mm1/include/linux/res_counter.h
> ===================================================================
> --- test-2.6.26-rc8-mm1.orig/include/linux/res_counter.h
> +++ test-2.6.26-rc8-mm1/include/linux/res_counter.h
> @@ -176,4 +176,19 @@ static inline bool res_counter_can_add(s
> return ret;
> }
>
> +static inline int res_counter_set_limit(struct res_counter *cnt,
> + unsigned long long limit)
> +{
> + unsigned long flags;
> + int ret = -EBUSY;
> +
> + spin_lock_irqsave(&cnt->lock, flags);
> + if (cnt->usage < limit) {
> + cnt->limit = limit;
> + ret = 0;
> + }
> + spin_unlock_irqrestore(&cnt->lock, flags);
> + return ret;
> +}
> +
> #endif
>
>