[PATCH -mm] constify sched.c stat_nam strings

[PATCH -mm] constify sched.c stat_nam strings

[Andreas Mohr]

Hi all,

Signed-off-by: Andreas Mohr <andi@lisas.de>


diff -urN linux-2.6.17-rc6-mm2.orig/kernel/sched.c linux-2.6.17-rc6-mm2.my/kernel/sched.c
--- linux-2.6.17-rc6-mm2.orig/kernel/sched.c	2006-06-13 19:28:17.000000000 +0200
+++ linux-2.6.17-rc6-mm2.my/kernel/sched.c	2006-06-13 19:32:03.000000000 +0200
@@ -4662,7 +4662,7 @@
 	task_t *relative;
 	unsigned state;
 	unsigned long free = 0;
-	static const char *stat_nam[] = { "R", "S", "D", "T", "t", "Z", "X" };
+	static const char * const stat_nam[] = { "R", "S", "D", "T", "t", "Z", "X" };
 
 	printk("%-13.13s ", p->comm);
 	state = p->state ? __ffs(p->state) + 1 : 0;

Re: [PATCH -mm] constify sched.c stat_nam strings

[Michael Tokarev]

Andreas Mohr wrote:
> Hi all,
> 
> Signed-off-by: Andreas Mohr <andi@lisas.de>
> 
> 
> diff -urN linux-2.6.17-rc6-mm2.orig/kernel/sched.c linux-2.6.17-rc6-mm2.my/kernel/sched.c
> --- linux-2.6.17-rc6-mm2.orig/kernel/sched.c	2006-06-13 19:28:17.000000000 +0200
> +++ linux-2.6.17-rc6-mm2.my/kernel/sched.c	2006-06-13 19:32:03.000000000 +0200
> @@ -4662,7 +4662,7 @@
>  	task_t *relative;
>  	unsigned state;
>  	unsigned long free = 0;
> -	static const char *stat_nam[] = { "R", "S", "D", "T", "t", "Z", "X" };
> +	static const char * const stat_nam[] = { "R", "S", "D", "T", "t", "Z", "X" };
>  
>  	printk("%-13.13s ", p->comm);
>  	state = p->state ? __ffs(p->state) + 1 : 0;

How about the following instead:

--- kernel/sched.c.orig 2006-05-31 22:23:53.000000000 +0400
+++ kernel/sched.c      2006-06-14 01:19:17.000000000 +0400
@@ -5287,14 +5287,11 @@ static void show_task(task_t *p)
 	task_t *relative;
 	unsigned state;
 	unsigned long free = 0;
-	static const char *stat_nam[] = { "R", "S", "D", "T", "t", "Z", "X" };
+	static const char stat_nam[] = "RSDTtZX";

-	printk("%-13.13s ", p->comm);
 	state = p->state ? __ffs(p->state) + 1 : 0;
-	if (state < ARRAY_SIZE(stat_nam))
-		printk(stat_nam[state]);
-	else
-		printk("?");
+	printk("%-13.13s %c", p->comm,
+		state < sizeof(stat_nam) - 1 ? stat_nam[state] : '?');
 #if (BITS_PER_LONG == 32)
 	printk(" %08lX ", (unsigned long)p);
 #else

?

/mjt

Re: [PATCH -mm] constify sched.c stat_nam strings

[Andreas Mohr]

Hi,

On Wed, Jun 14, 2006 at 01:22:31AM +0400, Michael Tokarev wrote:
> Andreas Mohr wrote:
> > Hi all,
> > 
> > Signed-off-by: Andreas Mohr <andi@lisas.de>
> > 
> > 
> > diff -urN linux-2.6.17-rc6-mm2.orig/kernel/sched.c linux-2.6.17-rc6-mm2.my/kernel/sched.c
> > --- linux-2.6.17-rc6-mm2.orig/kernel/sched.c	2006-06-13 19:28:17.000000000 +0200
> > +++ linux-2.6.17-rc6-mm2.my/kernel/sched.c	2006-06-13 19:32:03.000000000 +0200
> > @@ -4662,7 +4662,7 @@
> >  	task_t *relative;
> >  	unsigned state;
> >  	unsigned long free = 0;
> > -	static const char *stat_nam[] = { "R", "S", "D", "T", "t", "Z", "X" };
> > +	static const char * const stat_nam[] = { "R", "S", "D", "T", "t", "Z", "X" };
> >  
> >  	printk("%-13.13s ", p->comm);
> >  	state = p->state ? __ffs(p->state) + 1 : 0;
> 
> How about the following instead:
> 
> --- kernel/sched.c.orig 2006-05-31 22:23:53.000000000 +0400
> +++ kernel/sched.c      2006-06-14 01:19:17.000000000 +0400
> @@ -5287,14 +5287,11 @@ static void show_task(task_t *p)
>  	task_t *relative;
>  	unsigned state;
>  	unsigned long free = 0;
> -	static const char *stat_nam[] = { "R", "S", "D", "T", "t", "Z", "X" };
> +	static const char stat_nam[] = "RSDTtZX";
> 
> -	printk("%-13.13s ", p->comm);
>  	state = p->state ? __ffs(p->state) + 1 : 0;
> -	if (state < ARRAY_SIZE(stat_nam))
> -		printk(stat_nam[state]);
> -	else
> -		printk("?");
> +	printk("%-13.13s %c", p->comm,
> +		state < sizeof(stat_nam) - 1 ? stat_nam[state] : '?');
>  #if (BITS_PER_LONG == 32)
>  	printk(" %08lX ", (unsigned long)p);
>  #else
> 
> ?

Sounds nice, especially as it saves 124 Bytes compared to my version.

I'm planning to merge it into my sched.c cleanup with proper attribution.

Thanks!

Andreas Mohr

[PATCH -mm] small kernel/sched.c cleanup

[Andreas Mohr]

- constify and optimize stat_nam (thanks to Michael Tokarev!)
- spelling and comment fixes

Run-tested on 2.6.17-mm4.

Signed-off-by: Andreas Mohr <andi@lisas.de>


diff -urN linux-2.6.17-mm4.orig/kernel/sched.c linux-2.6.17-mm4.my/kernel/sched.c
--- linux-2.6.17-mm4.orig/kernel/sched.c	2006-06-29 11:57:17.000000000 +0200
+++ linux-2.6.17-mm4.my/kernel/sched.c	2006-06-29 21:48:22.000000000 +0200
@@ -3418,7 +3418,7 @@
 
 #ifdef CONFIG_PREEMPT
 /*
- * this is is the entry point to schedule() from in-kernel preemption
+ * this is the entry point to schedule() from in-kernel preemption
  * off of preempt_enable.  Kernel preemptions off return from interrupt
  * occur there and call schedule directly.
  */
@@ -3461,7 +3461,7 @@
 EXPORT_SYMBOL(preempt_schedule);
 
 /*
- * this is is the entry point to schedule() from kernel preemption
+ * this is the entry point to schedule() from kernel preemption
  * off of irq context.
  * Note, that this is called and return with irqs disabled. This will
  * protect us against recursive calling from irq.
@@ -3473,7 +3473,7 @@
 	struct task_struct *task = current;
 	int saved_lock_depth;
 #endif
-	/* Catch callers which need to be fixed*/
+	/* Catch callers which need to be fixed */
 	BUG_ON(ti->preempt_count || !irqs_disabled());
 
 need_resched:
@@ -4689,7 +4689,7 @@
 	return list_entry(p->sibling.next,struct task_struct,sibling);
 }
 
-static const char *stat_nam[] = { "R", "S", "D", "T", "t", "Z", "X" };
+static const char stat_nam[] = "RSDTtZX";
 
 static void show_task(struct task_struct *p)
 {
@@ -4697,12 +4697,9 @@
 	unsigned long free = 0;
 	unsigned state;
 
-	printk("%-13.13s ", p->comm);
 	state = p->state ? __ffs(p->state) + 1 : 0;
-	if (state < ARRAY_SIZE(stat_nam))
-		printk(stat_nam[state]);
-	else
-		printk("?");
+	printk("%-13.13s %c", p->comm,
+		state < sizeof(stat_nam) - 1 ? stat_nam[state] : '?');
 #if (BITS_PER_LONG == 32)
 	if (state == TASK_RUNNING)
 		printk(" running ");
@@ -5929,7 +5926,7 @@
 	cache = vmalloc(max_size);
 	if (!cache) {
 		printk("could not vmalloc %d bytes for cache!\n", 2*max_size);
-		return 1000000; // return 1 msec on very small boxen
+		return 1000000; /* return 1 msec on very small boxen */
 	}
 
 	while (size <= max_size) {

Re: [PATCH -mm] small kernel/sched.c cleanup

[Ingo Molnar]

* Andreas Mohr <andi@rhlx01.fht-esslingen.de> wrote:

> - constify and optimize stat_nam (thanks to Michael Tokarev!)
> - spelling and comment fixes
> 
> Run-tested on 2.6.17-mm4.
> 
> Signed-off-by: Andreas Mohr <andi@lisas.de>

looks good to me.

Acked-by: Ingo Molnar <mingo@elte.hu>

	Ingo