ipc: scale msgmni to the number of ipc namespaces

Since all the namespaces see the same amount of memory (the total one) this
patch introduces a new variable that counts the ipc namespaces and divides
msg_ctlmni by this counter.

Signed-off-by: Nadia Derbey <Nadia.Derbey@bull.net>
Cc: Yasunori Goto <y-goto@jp.fujitsu.com>
Cc: Matt Helsley <matthltc@us.ibm.com>
Cc: Mingming Cao <cmm@us.ibm.com>
Cc: Pierre Peiffer <pierre.peiffer@bull.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 3 insertions, 0 deletions

diff --git a/ipc/namespace.c b/ipc/namespace.c
index 1b967655eb35..fe3c97aa99dc 100644
--- a/ipc/namespace.c
+++ b/ipc/namespace.c
@@ -20,6 +20,8 @@ static struct ipc_namespace *clone_ipc_ns(struct ipc_namespace *old_ns)
         if (ns == NULL)
                 return ERR_PTR(-ENOMEM);
 
+        atomic_inc(&nr_ipc_ns);
+
         sem_init_ns(ns);
         msg_init_ns(ns);
         shm_init_ns(ns);
@@ -83,4 +85,5 @@ void free_ipc_ns(struct kref *kref)
         msg_exit_ns(ns);
         shm_exit_ns(ns);
         kfree(ns);
+        atomic_dec(&nr_ipc_ns);
 }