[RFC][PATCH 2.5.70] Static tunable semvmx and semaem

Arvind Kandhare (arvind.kan@wipro.com)
Fri, 06 Jun 2003 11:23:23 +0530


Hi,
Please find below patch(RFC) for implementing semvmx and semaem
as static tunable parameters.

These can be modified at boot time using command line interface.

Please comment/suggest.

cheers,
Arvind

diff -Naur linux-2.5.70/include/linux/sysctl.h linux-2.5.70.n/include/linux/sysctl.h
--- linux-2.5.70/include/linux/sysctl.h Tue May 27 06:30:40 2003
+++ linux-2.5.70.n/include/linux/sysctl.h Wed Jun 4 16:21:19 2003
@@ -130,6 +130,8 @@
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_SEMVMX=58, /* int: maximum limit on semval */
+
KERN_SEMAEM=59,
/* int: maximun limit on semaem */
};

diff -Naur linux-2.5.70/init/main.c linux-2.5.70.n/init/main.c
--- linux-2.5.70/init/main.c Tue May 27 06:30:25 2003
+++ linux-2.5.70.n/init/main.c Wed Jun 4 16:19:46 2003
@@ -67,6 +67,9 @@

extern char *linux_banner;

+extern unsigned int semvmx;
+extern unsigned int semaem;
+
static int init(void *);

extern void init_IRQ(void);
@@ -141,6 +144,29 @@

__setup("maxcpus=", maxcpus);

+static int __init _semvmx(char *str)
+{
+
get_option(&str, &semvmx);
+
if(semvmx>65535 || semvmx <=0)
+
{
+
semvmx=32767;
+
}
+
return 1;
+}
+__setup("semvmx=", _semvmx);
+
+static int __init _semaem(char *str)
+{
+
get_option(&str, &semaem);
+
if(semaem>32767 || semaem <=0)
+
{
+
semaem=16384;
+
}
+
return 1;
+}
+__setup("semaem=", _semaem);
+
+
static char * argv_init[MAX_INIT_ARGS+2] = { "init", NULL, };
char * envp_init[MAX_INIT_ENVS+2] = { "HOME=/", "TERM=linux", NULL, };

diff -Naur linux-2.5.70/ipc/sem.c linux-2.5.70.n/ipc/sem.c
--- linux-2.5.70/ipc/sem.c Tue May 27 06:30:38 2003
+++ linux-2.5.70.n/ipc/sem.c Wed Jun 4 17:01:46 2003
@@ -102,6 +102,9 @@
#define sc_semopm (sem_ctls[2])
#define sc_semmni (sem_ctls[3])

+unsigned int semvmx=32767;
+int semaem=16384;
+
static int used_sems;

void __init sem_init (void)
@@ -280,7 +283,7 @@

/*
* Exceeding the undo range is an error.

*/
-
if (undo < (-SEMAEM - 1) || undo > SEMAEM)
+
if (undo < (-semaem - 1) || undo > semaem)

{

/* Don't undo the undo */

sop->sem_flg &= ~SEM_UNDO;
@@ -290,7 +293,7 @@
}
if (curr->semval < 0)

goto would_block;
-
if (curr->semval > SEMVMX)
+
if (curr->semval > semvmx)

goto out_of_range;
}

@@ -482,7 +485,7 @@
seminfo.semmns = sc_semmns;
seminfo.semmsl = sc_semmsl;
seminfo.semopm = sc_semopm;
-
seminfo.semvmx = SEMVMX;
+
seminfo.semvmx = semvmx;
seminfo.semmnu = SEMMNU;
seminfo.semmap = SEMMAP;
seminfo.semume = SEMUME;
@@ -492,7 +495,7 @@

seminfo.semaem = used_sems;
} else {

seminfo.semusz = SEMUSZ;
-
seminfo.semaem = SEMAEM;
+
seminfo.semaem = semaem;
}
max_id = sem_ids.max_id;
up(&sem_ids.sem);
@@ -613,7 +616,7 @@
}

for (i = 0; i < nsems; i++) {
-
if (sem_io[i] > SEMVMX) {
+
if (sem_io[i] > semvmx) {

err = -ERANGE;

goto out_free;

}
@@ -672,7 +675,7 @@
int val = arg.val;
struct sem_undo *un;
err = -ERANGE;
-
if (val > SEMVMX || val < 0)
+
if (val > semvmx || val < 0)

goto out_unlock;

for (un = sma->undo; un; un = un->id_next)
diff -Naur linux-2.5.70/kernel/sysctl.c linux-2.5.70.n/kernel/sysctl.c
--- linux-2.5.70/kernel/sysctl.c Tue May 27 06:30:23 2003
+++ linux-2.5.70.n/kernel/sysctl.c Wed Jun 4 17:02:52 2003
@@ -79,6 +79,8 @@
extern int msg_ctlmnb;
extern int msg_ctlmni;
extern int sem_ctls[];
+extern unsigned int semvmx;
+extern int semaem;
#endif

#ifdef __sparc__
@@ -237,6 +239,10 @@
0644, NULL, &proc_dointvec},
{KERN_SEM, "sem", &sem_ctls, 4*sizeof (int),
0644, NULL, &proc_dointvec},
+
{KERN_SEMVMX, "semvmx", &semvmx, sizeof (int),
+
0444, NULL, &proc_dointvec},
+
{KERN_SEMAEM, "semaem", &semaem, sizeof (int),
+
0444, NULL, &proc_dointvec},
#endif
#ifdef CONFIG_MAGIC_SYSRQ
{KERN_SYSRQ, "sysrq", &sysrq_enabled, sizeof (int),

-
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