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 14c483d..92d4106 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.
+         Now, memory usage of swap_cgroup is 2 bytes per entry. If swap page
+         size is 4096bytes, 512k per 1Gbytes of swap.
 
 endif # CGROUPS
 

diff --git a/mm/page_cgroup.c b/mm/page_cgroup.c
index ebf8107..791905c 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);
 
-       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");