[Devel] [PATCH rh7 1/6] memcg: add function to get max mem+swap

[Vladimir Davydov]

This patch renames mem_cgroup_rap_pages to mem_cgroup_total_pages and
adds a bool argument to it, swap, which if set will result in the
function returning mem+swap limit instead of mem limit.

This is required for showing correct /proc/PID/oom_score inside a CT,
which is a business of the following patch.

Signed-off-by: Vladimir Davydov <vdavydov at parallels.com>
---
 include/linux/memcontrol.h | 4 ++--
 kernel/bc/io_acct.c        | 2 +-
 mm/memcontrol.c            | 8 ++++++--
 mm/shmem.c                 | 2 +-
 4 files changed, 10 insertions(+), 6 deletions(-)

diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h
index d434d6c2cf27..4980f9f16d6f 100644
--- a/include/linux/memcontrol.h
+++ b/include/linux/memcontrol.h
@@ -127,7 +127,7 @@ extern void mem_cgroup_print_oom_info(struct mem_cgroup *memcg,
 					struct task_struct *p);
 extern void mem_cgroup_replace_page_cache(struct page *oldpage,
 					struct page *newpage);
-unsigned long mem_cgroup_ram_pages(void);
+unsigned long mem_cgroup_total_pages(bool swap);
 
 #ifdef CONFIG_MEMCG_SWAP
 extern int do_swap_account;
@@ -402,7 +402,7 @@ static inline void mem_cgroup_replace_page_cache(struct page *oldpage,
 {
 }
 
-static inline unsigned long mem_cgroup_ram_pages(void)
+static inline unsigned long mem_cgroup_total_pages(swap)
 {
 	return ULONG_MAX;
 }
diff --git a/kernel/bc/io_acct.c b/kernel/bc/io_acct.c
index ee30fea69926..50f8fb781703 100644
--- a/kernel/bc/io_acct.c
+++ b/kernel/bc/io_acct.c
@@ -135,7 +135,7 @@ int ub_dirty_limits(unsigned long *pbackground,
 	if (!dirty_ratio)
 		return 0;
 
-	available_memory = mem_cgroup_ram_pages();
+	available_memory = mem_cgroup_total_pages(false);
 	if (available_memory == ULONG_MAX || available_memory == 0)
 		return 0;
 
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 92928937f900..a70f9d82e798 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -1638,8 +1638,11 @@ void mem_cgroup_note_oom_kill(struct mem_cgroup *root_memcg,
  * cgroup. If it is changed, this function must be reworked. E.g. we could
  * assign a memory cgroup to each ve or beancounter cgroup and get the memory
  * cgroup of a container from get_exec_env() or get_exec_ub().
+ *
+ * If @swap is true, this function returns the total number of memory + swap
+ * pages available.
  */
-unsigned long mem_cgroup_ram_pages(void)
+unsigned long mem_cgroup_total_pages(bool swap)
 {
 	struct mem_cgroup *memcg_to_put, *memcg, *parent;
 	unsigned long long limit = RESOURCE_MAX;
@@ -1652,7 +1655,8 @@ unsigned long mem_cgroup_ram_pages(void)
 	       parent != root_mem_cgroup)
 		memcg = parent;
 
-	limit = res_counter_read_u64(&memcg->res, RES_LIMIT);
+	limit = swap ? res_counter_read_u64(&memcg->memsw, RES_LIMIT) :
+			res_counter_read_u64(&memcg->res, RES_LIMIT);
 out:
 	if (memcg_to_put)
 		css_put(&memcg_to_put->css);
diff --git a/mm/shmem.c b/mm/shmem.c
index 0c8d6aec7f07..88a6552775c0 100644
--- a/mm/shmem.c
+++ b/mm/shmem.c
@@ -111,7 +111,7 @@ static unsigned long tmpfs_ram_pages(void)
 	if (ve_is_super(get_exec_env()))
 		return totalram_pages;
 
-	memcg_rampages = mem_cgroup_ram_pages();
+	memcg_rampages = mem_cgroup_total_pages(false);
 	return min(totalram_pages, memcg_rampages);
 }
 
-- 
2.1.4