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 { ...@@ -33,6 +33,7 @@ struct ipc_namespace {
}; };
extern struct ipc_namespace init_ipc_ns; extern struct ipc_namespace init_ipc_ns;
extern atomic_t nr_ipc_ns;
#ifdef CONFIG_SYSVIPC #ifdef CONFIG_SYSVIPC
#define INIT_IPC_NS(ns) .ns = &init_ipc_ns, #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); ...@@ -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 * Scale msgmni with the available lowmem size: the memory dedicated to msg
* queues should occupy at most 1/MSG_MEM_SCALE of lowmem. * 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) static void recompute_msgmni(struct ipc_namespace *ns)
{ {
struct sysinfo i; struct sysinfo i;
unsigned long allowed; unsigned long allowed;
int nb_ns;
si_meminfo(&i); si_meminfo(&i);
allowed = (((i.totalram - i.totalhigh) / MSG_MEM_SCALE) * i.mem_unit) allowed = (((i.totalram - i.totalhigh) / MSG_MEM_SCALE) * i.mem_unit)
/ MSGMNB; / MSGMNB;
nb_ns = atomic_read(&nr_ipc_ns);
allowed /= nb_ns;
if (allowed < MSGMNI) { if (allowed < MSGMNI) {
ns->msg_ctlmni = MSGMNI; ns->msg_ctlmni = MSGMNI;
goto out_callback; goto out_callback;
} }
if (allowed > IPCMNI) { if (allowed > IPCMNI / nb_ns) {
ns->msg_ctlmni = IPCMNI; ns->msg_ctlmni = IPCMNI / nb_ns;
goto out_callback; goto out_callback;
} }
......
...@@ -20,6 +20,8 @@ static struct ipc_namespace *clone_ipc_ns(struct ipc_namespace *old_ns) ...@@ -20,6 +20,8 @@ static struct ipc_namespace *clone_ipc_ns(struct ipc_namespace *old_ns)
if (ns == NULL) if (ns == NULL)
return ERR_PTR(-ENOMEM); return ERR_PTR(-ENOMEM);
atomic_inc(&nr_ipc_ns);
sem_init_ns(ns); sem_init_ns(ns);
msg_init_ns(ns); msg_init_ns(ns);
shm_init_ns(ns); shm_init_ns(ns);
...@@ -83,4 +85,5 @@ void free_ipc_ns(struct kref *kref) ...@@ -83,4 +85,5 @@ void free_ipc_ns(struct kref *kref)
msg_exit_ns(ns); msg_exit_ns(ns);
shm_exit_ns(ns); shm_exit_ns(ns);
kfree(ns); kfree(ns);
atomic_dec(&nr_ipc_ns);
} }
...@@ -52,6 +52,9 @@ struct ipc_namespace init_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 * ipc_init - initialise IPC subsystem
* *
......
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