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>
diff --git a/ipc/msg.c b/ipc/msg.c
index 9e72111..be8449d 100644
--- a/ipc/msg.c
+++ b/ipc/msg.c
@@ -81,24 +81,28 @@
/*
* Scale msgmni with the available lowmem size: the memory dedicated to msg
* queues should occupy at most 1/MSG_MEM_SCALE of lowmem.
- * This should be done staying within the (MSGMNI , IPCMNI) range.
+ * Also take into account the number of nsproxies created so far.
+ * This should be done staying within the (MSGMNI , IPCMNI/nr_ipc_ns) range.
*/
static void recompute_msgmni(struct ipc_namespace *ns)
{
struct sysinfo i;
unsigned long allowed;
+ int nb_ns;
si_meminfo(&i);
allowed = (((i.totalram - i.totalhigh) / MSG_MEM_SCALE) * i.mem_unit)
/ MSGMNB;
+ nb_ns = atomic_read(&nr_ipc_ns);
+ allowed /= nb_ns;
if (allowed < MSGMNI) {
ns->msg_ctlmni = MSGMNI;
goto out_callback;
}
- if (allowed > IPCMNI) {
- ns->msg_ctlmni = IPCMNI;
+ if (allowed > IPCMNI / nb_ns) {
+ ns->msg_ctlmni = IPCMNI / nb_ns;
goto out_callback;
}