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, 1 insertions, 0 deletions

diff --git a/include/linux/ipc_namespace.h b/include/linux/ipc_namespace.h
index e4451d1da753..878d7ac286fa 100644
--- a/include/linux/ipc_namespace.h
+++ b/include/linux/ipc_namespace.h
@@ -33,6 +33,7 @@ struct ipc_namespace {
 };
 
 extern struct ipc_namespace init_ipc_ns;
+extern atomic_t nr_ipc_ns;
 
 #ifdef CONFIG_SYSVIPC
 #define INIT_IPC_NS(ns)         .ns             = &init_ipc_ns,