ipc: scale msgmni to the number of ipc namespaces

[safe/jmp/linux-2.6] / ipc / msg.c

diff --git a/ipc/msg.c b/ipc/msg.c
index 9e72111..be8449d 100644 (file)
--- a/ipc/msg.c
+++ b/ipc/msg.c
@@ -81,24 +81,28 @@ static int sysvipc_msg_proc_show(struct seq_file *s, void *it);
 /*
  * 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;
        }