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dynamically tuning msgtql

RFC PATCH New Dhruv Anand 1 participant 1 message Jun 6, 2003 Proc sysctl

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Dhruv Anand

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RFC PATCH 1/1 dynamically tuning msgtql

Hi,
Please find below the patch (RFC) that makes msgtql dynamically tunable through /proc interface.

1) IPC_NOWAIT flag not handled.
Handling this will cause overheads (additional queue, wake-ups etc). Please comment.

Or Handling IPC_NOWAIT may require:
a) An additional global queue for processes when message to be queued is > msgtql && IPC_NOWAIT flag is not set. Please comment.

Thanks,
Dhruv

include/linux/msg.h +4 -4
diff -Nur linux-2.5.70/include/linux/msg.h linux-2.5.70msg/include/linux/msg.h
@@ -49,13 +49,13 @@
 	unsigned short  msgseg; 
 };
 
-#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 */
+#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 */
+#define MSGTQL 0x7fffffff /* <= INT_MAX */   /* number of system message */
 
 /* unused */
 #define MSGPOOL (MSGMNI*MSGMNB/1024)  /* size in kilobytes 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 */
include/linux/sysctl.h +1 -0
diff -Nur linux-2.5.70/include/linux/sysctl.h linux-2.5.70msg/include/linux/sysctl.h
@@ -130,6 +130,7 @@
 	KERN_PIDMAX=55,		/* int: PID # limit */
   	KERN_CORE_PATTERN=56,	/* string: pattern for core-file names */
 	KERN_PANIC_ON_OOPS=57,  /* int: whether we will panic on an oops */
+	KERN_MSGTQL=57,         /* int: Maximum number of messages system wide */
 };
ipc/msg.c +51 -34

111 lines not on this page · raw message

kernel/sysctl.c +6 -3
diff -Nur linux-2.5.70/kernel/sysctl.c linux-2.5.70msg/kernel/sysctl.c
@@ -61,6 +61,9 @@
 /* this is needed for the proc_dointvec_minmax for [fs_]overflow UID and GID */
 static int maxolduid = 65535;
 static int minolduid;
+static int zero = 0;
+static int one = 1;
+static int one_hundred = 100;
 
 #ifdef CONFIG_KMOD
 extern char modprobe_path[];

@@ -78,6 +81,7 @@
 extern int msg_ctlmax;
 extern int msg_ctlmnb;
 extern int msg_ctlmni;
+extern int msg_ctltql;
 extern int sem_ctls[];
 #endif
 

@@ -235,6 +239,8 @@
 	 0644, NULL, &proc_dointvec},
 	{KERN_MSGMNB, "msgmnb", &msg_ctlmnb, sizeof (int),
 	 0644, NULL, &proc_dointvec},
+	{KERN_MSGTQL, "msgtql", &msg_ctltql, sizeof (int),
+         0644, NULL, &proc_dointvec_minmax, NULL, NULL, &zero, NULL},
 	{KERN_SEM, "sem", &sem_ctls, 4*sizeof (int),
 	 0644, NULL, &proc_dointvec},
 #endif

@@ -270,9 +276,6 @@
 
 /* Constants for minimum and maximum testing in vm_table.
    We use these as one-element integer vectors. */
-static int zero = 0;
-static int one = 1;
-static int one_hundred = 100;
 
 
 static ctl_table vm_table[] = {