Commit 4d89dc6a authored by Nadia Derbey's avatar Nadia Derbey Committed by Linus Torvalds

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: default avatarNadia 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: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent f7bf3df8
......@@ -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,
......
......@@ -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;
}
......
......@@ -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);
}
......@@ -52,6 +52,9 @@ struct ipc_namespace init_ipc_ns = {
},
};
atomic_t nr_ipc_ns = ATOMIC_INIT(1);
/**
* ipc_init - initialise IPC subsystem
*
......
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