memcg: remove redundant message at swapon

It's pointed out that swap_cgroup's message at swapon() is nonsense.
Because

  * It can be calculated very easily if all necessary information is
    written in Kconfig.

  * It's not necessary to annoying people at every swapon().

In other view, now, memory usage per swp_entry is reduced to 2bytes from
8bytes(64bit) and I think it's reasonably small.

Reported-by: Hugh Dickins <hugh@veritas.com>
Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/init/Kconfig b/init/Kconfig
index 14c483d2b7c90b4a5713b6ed116fa16260f1228d..92d410603932f83d9e6c545c901616bb1eb45389 100644 (file)
--- a/init/Kconfig
+++ b/init/Kconfig
@@ -597,6 +597,8 @@ config CGROUP_MEM_RES_CTLR_SWAP
          is disabled by boot option, this will be automatically disabled and
          there will be no overhead from this. Even when you set this config=y,
          if boot option "noswapaccount" is set, swap will not be accounted.
          is disabled by boot option, this will be automatically disabled and
          there will be no overhead from this. Even when you set this config=y,
          if boot option "noswapaccount" is set, swap will not be accounted.

+         Now, memory usage of swap_cgroup is 2 bytes per entry. If swap page
+         size is 4096bytes, 512k per 1Gbytes of swap.

 
 endif # CGROUPS
 
 
 endif # CGROUPS
 

diff --git a/mm/page_cgroup.c b/mm/page_cgroup.c
index ebf81074bed48ff68ddba8b1525a4bde7c7136bc..791905c991df9d94497c36cd23cb3fead537f4d9 100644 (file)
--- a/mm/page_cgroup.c
+++ b/mm/page_cgroup.c
@@ -426,13 +426,6 @@ int swap_cgroup_swapon(int type, unsigned long max_pages)
        }
        mutex_unlock(&swap_cgroup_mutex);
 
        }
        mutex_unlock(&swap_cgroup_mutex);
 

-       printk(KERN_INFO
-               "swap_cgroup: uses %ld bytes of vmalloc for pointer array space"
-               " and %ld bytes to hold mem_cgroup information per swap ents\n",
-               array_size, length * PAGE_SIZE);
-       printk(KERN_INFO
-       "swap_cgroup can be disabled by noswapaccount boot option.\n");
-

        return 0;
 nomem:
        printk(KERN_INFO "couldn't allocate enough memory for swap_cgroup.\n");
        return 0;
 nomem:
        printk(KERN_INFO "couldn't allocate enough memory for swap_cgroup.\n");