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authorPaul Mackerras <paulus@samba.org>2008-05-09 20:12:06 +1000
committerPaul Mackerras <paulus@samba.org>2008-05-09 20:12:06 +1000
commit2a5f2e3e6cd1ce9fb3f8b186b6bc9aa1f1497a92 (patch)
treeb2306840f227972a7c9d4a2b75e516fe81358ce8 /include/linux/msg.h
parent02539d71fa98d5737bb668b02286c76241e4bac9 (diff)
parent78be76476a34a77f0ea9db2f78ba46a2b0fd5ab5 (diff)
Merge branch 'for-2.6.26' of master.kernel.org:/pub/scm/linux/kernel/git/jwboyer/powerpc-4xx into merge
Diffstat (limited to 'include/linux/msg.h')
-rw-r--r--include/linux/msg.h14
1 files changed, 12 insertions, 2 deletions
diff --git a/include/linux/msg.h b/include/linux/msg.h
index 10a3d5a1abff..6f3b8e79a991 100644
--- a/include/linux/msg.h
+++ b/include/linux/msg.h
@@ -49,16 +49,26 @@ struct msginfo {
unsigned short msgseg;
};
+/*
+ * Scaling factor to compute msgmni:
+ * the memory dedicated to msg queues (msgmni * msgmnb) should occupy
+ * at most 1/MSG_MEM_SCALE of the lowmem (see the formula in ipc/msg.c):
+ * up to 8MB : msgmni = 16 (MSGMNI)
+ * 4 GB : msgmni = 8K
+ * more than 16 GB : msgmni = 32K (IPCMNI)
+ */
+#define MSG_MEM_SCALE 32
+
#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 (MSGPOOL / MSGSSZ) /* max no. of segments */
#define MSGSEG (__MSGSEG <= 0xffff ? __MSGSEG : 0xffff)
#ifdef __KERNEL__