memcg: export struct mem_cgroup
mem_cgroup structure is defined in mm/memcontrol.c currently which means
that the code outside of this file has to use external API even for
trivial access stuff.
This patch exports mm_struct with its dependencies and makes some of the
exported functions inlines. This even helps to reduce the code size a bit
(make defconfig + CONFIG_MEMCG=y)
text data bss dec hex filename
12355346 1823792 1089536 15268674 e8fb42 vmlinux.before
12354970 1823792 1089536 15268298 e8f9ca vmlinux.after
This is not much (370B) but better than nothing.
We also save a function call in some hot paths like callers of
mem_cgroup_count_vm_event which is used for accounting.
The patch doesn't introduce any functional changes.
[vdavykov@parallels.com: inline memcg_kmem_is_active]
[vdavykov@parallels.com: do not expose type outside of CONFIG_MEMCG]
[akpm@linux-foundation.org: memcontrol.h needs eventfd.h for eventfd_ctx]
[akpm@linux-foundation.org: export mem_cgroup_from_task() to modules]
Signed-off-by: Michal Hocko <mhocko@suse.cz>
Reviewed-by: Vladimir Davydov <vdavydov@parallels.com>
Suggested-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Tejun Heo <tj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/include/linux/swap.h b/include/linux/swap.h
index 6282f1e..2ce1907 100644
--- a/include/linux/swap.h
+++ b/include/linux/swap.h
@@ -351,7 +351,15 @@
extern int kswapd_run(int nid);
extern void kswapd_stop(int nid);
#ifdef CONFIG_MEMCG
-extern int mem_cgroup_swappiness(struct mem_cgroup *mem);
+static inline int mem_cgroup_swappiness(struct mem_cgroup *memcg)
+{
+ /* root ? */
+ if (mem_cgroup_disabled() || !memcg->css.parent)
+ return vm_swappiness;
+
+ return memcg->swappiness;
+}
+
#else
static inline int mem_cgroup_swappiness(struct mem_cgroup *mem)
{