[PATCH] Add get_range, allows a hyhpenated range to get_options

[PATCH] Add get_range, allows a hyhpenated range to get_options

[Derek Fults]

This allows a hyphenated range of positive numbers in the string passed
to command line helper function, get_options.    
Currently the command line option "isolcpus=" takes as its argument a
list of cpus.  
Format: <cpu number>,...,<cpu number>
This can get extremely long when isolating the majority of cpus on a
large system.  Valid values of <cpu_number>  include all cpus, 0 to
"number of CPUs in system - 1".

Signed-off-by: Derek Fults <dfults@sgi.com>  

Index: linux/lib/cmdline.c
===================================================================
--- linux.orig/lib/cmdline.c	2006-09-19 22:42:06.000000000 -0500
+++ linux/lib/cmdline.c	2006-11-01 10:16:09.988659834 -0600
@@ -16,6 +16,21 @@
 #include <linux/kernel.h>
 #include <linux/string.h>
 
+/* If a hyphen was found in get_option, this will handle the 
+ * range of numbers given. 
+ */
+
+static int get_range(char **str, int *pint)
+{
+	int x, inc_counter = 0, upper_range = 0;
+
+	(*str)++;
+	upper_range = simple_strtol((*str), NULL, 0);
+	inc_counter = upper_range - *pint;
+	for (x = *pint; x < upper_range; x++)
+		*pint++ = x;
+	return inc_counter;
+}
 
 /**
  *	get_option - Parse integer from an option string
@@ -29,6 +44,7 @@
  *	0 : no int in string
  *	1 : int found, no subsequent comma
  *	2 : int found including a subsequent comma
+ *	3 : hyphen found to denote a range
  */
 
 int get_option (char **str, int *pint)
@@ -44,6 +60,8 @@
 		(*str)++;
 		return 2;
 	}
+	if (**str == '-')
+		return 3;
 
 	return 1;
 }
@@ -55,7 +73,8 @@
  *	@ints: integer array
  *
  *	This function parses a string containing a comma-separated
- *	list of integers.  The parse halts when the array is
+ *	list of integers, a hyphen-separated range of _positive_ integers,
+ *	or a combination of both.  The parse halts when the array is
  *	full, or when no more numbers can be retrieved from the
  *	string.
  *
@@ -72,6 +91,14 @@
 		res = get_option ((char **)&str, ints + i);
 		if (res == 0)
 			break;
+		if (res == 3) {
+			int range_nums = 0;
+			range_nums = get_range((char **)&str, ints + i);
+			/* Decrement the result by one to leave out the
+			   last number in the range.  The next iteration
+			   will handle the upper number in the range */
+			i += (range_nums - 1);
+		}
 		i++;
 		if (res == 1)
 			break;

Re: [PATCH] Add get_range, allows a hyhpenated range to get_options

[Randy Dunlap]

On Wed, 01 Nov 2006 10:22:36 -0600 Derek Fults wrote:

> This allows a hyphenated range of positive numbers in the string passed
> to command line helper function, get_options.    
> Currently the command line option "isolcpus=" takes as its argument a
> list of cpus.  
> Format: <cpu number>,...,<cpu number>
> This can get extremely long when isolating the majority of cpus on a
> large system.  Valid values of <cpu_number>  include all cpus, 0 to
> "number of CPUs in system - 1".
> 
> Signed-off-by: Derek Fults <dfults@sgi.com>  
> 
> Index: linux/lib/cmdline.c
> ===================================================================
> --- linux.orig/lib/cmdline.c	2006-09-19 22:42:06.000000000 -0500
> +++ linux/lib/cmdline.c	2006-11-01 10:16:09.988659834 -0600
> @@ -16,6 +16,21 @@
>  #include <linux/kernel.h>
>  #include <linux/string.h>
>  
> +/* If a hyphen was found in get_option, this will handle the 
> + * range of numbers given. 

Still have trailing whitespace in the patch (2 lines above).

I think that this comment should explain that the M-N range
is handled by expanding it to an array of [M, M+1, ..., N].


> + */
> +
> +static int get_range(char **str, int *pint)
> +{
> +	int x, inc_counter = 0, upper_range = 0;

No need to init these variables.

> +	(*str)++;
> +	upper_range = simple_strtol((*str), NULL, 0);
> +	inc_counter = upper_range - *pint;
> +	for (x = *pint; x < upper_range; x++)
> +		*pint++ = x;
> +	return inc_counter;
> +}
>  
>  /**
>   *	get_option - Parse integer from an option string
> @@ -29,6 +44,7 @@
>   *	0 : no int in string
>   *	1 : int found, no subsequent comma
>   *	2 : int found including a subsequent comma
> + *	3 : hyphen found to denote a range
>   */
>  
>  int get_option (char **str, int *pint)
> @@ -44,6 +60,8 @@
>  		(*str)++;
>  		return 2;
>  	}
> +	if (**str == '-')
> +		return 3;
>  
>  	return 1;
>  }
> @@ -55,7 +73,8 @@
>   *	@ints: integer array
>   *
>   *	This function parses a string containing a comma-separated
> - *	list of integers.  The parse halts when the array is
> + *	list of integers, a hyphen-separated range of _positive_ integers,
> + *	or a combination of both.  The parse halts when the array is
>   *	full, or when no more numbers can be retrieved from the
>   *	string.
>   *
> @@ -72,6 +91,14 @@
>  		res = get_option ((char **)&str, ints + i);
>  		if (res == 0)
>  			break;
> +		if (res == 3) {
> +			int range_nums = 0;

no need to init the variable.

> +			range_nums = get_range((char **)&str, ints + i);
> +			/* Decrement the result by one to leave out the
> +			   last number in the range.  The next iteration
> +			   will handle the upper number in the range */
> +			i += (range_nums - 1);
> +		}
>  		i++;
>  		if (res == 1)
>  			break;
> -


---
~Randy

Re: [PATCH] Add get_range, allows a hyhpenated range to get_options

[Derek Fults]

On Wed, 2006-11-01 at 08:57 -0800, Randy Dunlap wrote:
> On Wed, 01 Nov 2006 10:22:36 -0600 Derek Fults wrote:
> 
> > This allows a hyphenated range of positive numbers in the string passed
> > to command line helper function, get_options.    
> > Currently the command line option "isolcpus=" takes as its argument a
> > list of cpus.  
> > Format: <cpu number>,...,<cpu number>
> > This can get extremely long when isolating the majority of cpus on a
> > large system.  Valid values of <cpu_number>  include all cpus, 0 to
> > "number of CPUs in system - 1".
> > 
> > Signed-off-by: Derek Fults <dfults@sgi.com>  
> > 
> > Index: linux/lib/cmdline.c
> > ===================================================================
> > --- linux.orig/lib/cmdline.c	2006-09-19 22:42:06.000000000 -0500
> > +++ linux/lib/cmdline.c	2006-11-01 10:16:09.988659834 -0600
> > @@ -16,6 +16,21 @@
> >  #include <linux/kernel.h>
> >  #include <linux/string.h>
> >  
> > +/* If a hyphen was found in get_option, this will handle the 
> > + * range of numbers given. 
> 
> Still have trailing whitespace in the patch (2 lines above).
> 
> I think that this comment should explain that the M-N range
> is handled by expanding it to an array of [M, M+1, ..., N].
> 
How's this for a description?

/* If a hyphen was found in get_option, this will handle the
 * range of numbers, M-N.  This will expand the range and insert
 * the values[M, M+1, ..., N] into the ints array in get_options.
 */

Thanks,
Derek

Re: [PATCH] Add get_range, allows a hyhpenated range to get_options

[Randy Dunlap]

Derek Fults wrote:
> On Wed, 2006-11-01 at 08:57 -0800, Randy Dunlap wrote:
>> On Wed, 01 Nov 2006 10:22:36 -0600 Derek Fults wrote:
>>
>>> This allows a hyphenated range of positive numbers in the string passed
>>> to command line helper function, get_options.    
>>> Currently the command line option "isolcpus=" takes as its argument a
>>> list of cpus.  
>>> Format: <cpu number>,...,<cpu number>
>>> This can get extremely long when isolating the majority of cpus on a
>>> large system.  Valid values of <cpu_number>  include all cpus, 0 to
>>> "number of CPUs in system - 1".
>>>
>>> Signed-off-by: Derek Fults <dfults@sgi.com>  
>>>
>>> Index: linux/lib/cmdline.c
>>> ===================================================================
>>> --- linux.orig/lib/cmdline.c	2006-09-19 22:42:06.000000000 -0500
>>> +++ linux/lib/cmdline.c	2006-11-01 10:16:09.988659834 -0600
>>> @@ -16,6 +16,21 @@
>>>  #include <linux/kernel.h>
>>>  #include <linux/string.h>
>>>  
>>> +/* If a hyphen was found in get_option, this will handle the 
>>> + * range of numbers given. 
>> Still have trailing whitespace in the patch (2 lines above).
>>
>> I think that this comment should explain that the M-N range
>> is handled by expanding it to an array of [M, M+1, ..., N].
>>
> How's this for a description?
> 
> /* If a hyphen was found in get_option, this will handle the
>  * range of numbers, M-N.  This will expand the range and insert
>  * the values[M, M+1, ..., N] into the ints array in get_options.
>  */

That text is good.  Please look at lib/cmdline.c and put this text
into the same comment-block format as the rest of the file.

How does get_range() handle errors, like input of
	64-60
or	64-N
or	64-
?

-- 
~Randy

Re: [PATCH] Add get_range, allows a hyhpenated range to get_options

[Derek Fults]

> How does get_range() handle errors, like input of
> 	64-60
> or	64-N
> or	64-
> ?
> 
get_range will return a negative value which caused it to break out of
the while loop on the next iteration.  I've added a check of the
get_range return value to break immediately. See snippet.  
If get_options is called with a bad range, 
64-N,65
returns and empty array.
63,64-N
returns an array with just 63.  

		if (res == 3) {
			int range_nums;
			range_nums = get_range((char **)&str, ints + i);
+			if ( range_nums < 0)
+					break;
			/* Decrement the result by one to leave out the
			   last number in the range.  The next iteration
			   will handle the upper number in the range */
			i += (range_nums - 1);
		}

Derek

Re: [PATCH] Add get_range, allows a hyhpenated range to get_options

[Randy Dunlap]

Derek Fults wrote:
>> How does get_range() handle errors, like input of
>> 	64-60
>> or	64-N
>> or	64-
>> ?
>>
> get_range will return a negative value which caused it to break out of
> the while loop on the next iteration.  I've added a check of the
> get_range return value to break immediately. See snippet.  
> If get_options is called with a bad range, 
> 64-N,65
> returns and empty array.
> 63,64-N
> returns an array with just 63.  

OK, thanks.

> 		if (res == 3) {
> 			int range_nums;
> 			range_nums = get_range((char **)&str, ints + i);
> +			if ( range_nums < 0)

no space after '('

> +					break;
> 			/* Decrement the result by one to leave out the
> 			   last number in the range.  The next iteration
> 			   will handle the upper number in the range */
> 			i += (range_nums - 1);
> 		}
> 
> Derek


-- 
~Randy