[PATCH 01/02]
This patch computes msg_ctlmni to make it scale with system memory.
msg_ctlmni is now set to make the message queues occupy 1/32 of the available
memory.
Some cleaning has also been done in the MSGXXX constants:
. MSGPOOL: the msgctl man page says it's not used, but it also defines it as
a size in bytes (the code expresses it in Kbytes).
. MSGSEG definition has been removed since it used only once in msgctl().
Signed-off-by: Nadia Derbey <[EMAIL PROTECTED]>
---
include/linux/msg.h | 6 +++---
ipc/msg.c | 20 ++++++++++++++++++--
2 files changed, 21 insertions(+), 5 deletions(-)
Index: linux-2.6.24-rc4/include/linux/msg.h
===================================================================
--- linux-2.6.24-rc4.orig/include/linux/msg.h 2007-12-11 11:57:53.000000000
+0100
+++ linux-2.6.24-rc4/include/linux/msg.h 2007-12-11 12:10:01.000000000
+0100
@@ -49,17 +49,17 @@ struct msginfo {
unsigned short msgseg;
};
+#define MSG_MEM_SCALE 32 /* Scaling factor to compute msgmni */
+
#define MSGMNI 16 /* <= IPCMNI */ /* max # of msg queue identifiers */
#define MSGMAX 8192 /* <= INT_MAX */ /* max size of message (bytes) */
#define MSGMNB 16384 /* <= INT_MAX */ /* default max size of a message
queue */
/* unused */
-#define MSGPOOL (MSGMNI*MSGMNB/1024) /* size in kilobytes of message pool */
+#define MSGPOOL (MSGMNI * MSGMNB) /* size in bytes of message pool */
#define MSGTQL MSGMNB /* number of system message headers */
#define MSGMAP MSGMNB /* number of entries in message map */
#define MSGSSZ 16 /* message segment size */
-#define __MSGSEG ((MSGPOOL*1024)/ MSGSSZ) /* max no. of segments */
-#define MSGSEG (__MSGSEG <= 0xffff ? __MSGSEG : 0xffff)
#ifdef __KERNEL__
#include <linux/list.h>
Index: linux-2.6.24-rc4/ipc/msg.c
===================================================================
--- linux-2.6.24-rc4.orig/ipc/msg.c 2007-12-11 11:57:58.000000000 +0100
+++ linux-2.6.24-rc4/ipc/msg.c 2007-12-11 12:12:32.000000000 +0100
@@ -27,6 +27,7 @@
#include <linux/msg.h>
#include <linux/spinlock.h>
#include <linux/init.h>
+#include <linux/mm.h>
#include <linux/proc_fs.h>
#include <linux/list.h>
#include <linux/security.h>
@@ -81,10 +82,25 @@ static int sysvipc_msg_proc_show(struct
static void __msg_init_ns(struct ipc_namespace *ns, struct ipc_ids *ids)
{
+ struct sysinfo i;
+ unsigned long allowed;
+
ns->ids[IPC_MSG_IDS] = ids;
ns->msg_ctlmax = MSGMAX;
ns->msg_ctlmnb = MSGMNB;
- ns->msg_ctlmni = MSGMNI;
+
+ /*
+ * Scale msgmni with the available memory size: the memory dedicated
+ * to msg queues should occupy 1/32 of the available memory:
+ * up to 8MB : msgmni = 16 (MSGMNI)
+ * 4 GB : msgmni = 8K
+ * more than 16 GB : msgmni = 32K (IPCMNI)
+ */
+ si_meminfo(&i);
+ allowed = ((i.totalram / MSG_MEM_SCALE) * i.mem_unit) / MSGMNB;
+ ns->msg_ctlmni = min((unsigned long) IPCMNI,
+ max((unsigned long) MSGMNI, allowed));
+
atomic_set(&ns->msg_bytes, 0);
atomic_set(&ns->msg_hdrs, 0);
ipc_init_ids(ids);
@@ -458,7 +474,7 @@ asmlinkage long sys_msgctl(int msqid, in
msginfo.msgmax = ns->msg_ctlmax;
msginfo.msgmnb = ns->msg_ctlmnb;
msginfo.msgssz = MSGSSZ;
- msginfo.msgseg = MSGSEG;
+ msginfo.msgseg = min(MSGPOOL / MSGSSZ, 0xffff);
down_read(&msg_ids(ns).rw_mutex);
if (cmd == MSG_INFO) {
msginfo.msgpool = msg_ids(ns).in_use;
--
--
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