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

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

include/linux/ipc_namespace.h

+1 −0
Original line number Diff line number Diff line
@@ -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,

ipc/msg.c

+7 −3
Original line number Diff line number Diff line
@@ -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;

	}

ipc/namespace.c

+3 −0
Original line number Diff line number Diff line
@@ -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);

}

ipc/util.c

+3 −0
Original line number Diff line number Diff line
@@ -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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