[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 --- 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 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 #include #include +#include #include #include #include @@ -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; -- -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/