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* [PATCH] i2o: fix notifiers when max_drivers is configured
@ 2007-05-20 14:27 Akinobu Mita
  2007-05-21  4:16 ` Andrew Morton
  0 siblings, 1 reply; 3+ messages in thread
From: Akinobu Mita @ 2007-05-20 14:27 UTC (permalink / raw)
  To: Markus Lidel; +Cc: linux-kernel

Maxinum number of I2O drivers which could be registered is
configurable by max_drivers module parameter.

But the module parameter is ignored and default value (I2O_MAX_DRIVERS = 8)
is used in the loops to notify all registered drivers.

Cc: Markus Lidel <Markus.Lidel@shadowconnect.com>
Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>

---
 drivers/message/i2o/driver.c |   14 +++++++-------
 1 file changed, 7 insertions(+), 7 deletions(-)

Index: 2.6-mm/drivers/message/i2o/driver.c
===================================================================
--- 2.6-mm.orig/drivers/message/i2o/driver.c
+++ 2.6-mm/drivers/message/i2o/driver.c
@@ -20,6 +20,7 @@
 #include <linux/workqueue.h>
 #include <linux/string.h>
 #include <linux/slab.h>
+#include <linux/log2.h>
 #include "core.h"
 
 #define OSM_NAME	"i2o"
@@ -260,7 +261,7 @@ void i2o_driver_notify_controller_add_al
 	int i;
 	struct i2o_driver *drv;
 
-	for (i = 0; i < I2O_MAX_DRIVERS; i++) {
+	for (i = 0; i < i2o_max_drivers; i++) {
 		drv = i2o_drivers[i];
 
 		if (drv)
@@ -280,7 +281,7 @@ void i2o_driver_notify_controller_remove
 	int i;
 	struct i2o_driver *drv;
 
-	for (i = 0; i < I2O_MAX_DRIVERS; i++) {
+	for (i = 0; i < i2o_max_drivers; i++) {
 		drv = i2o_drivers[i];
 
 		if (drv)
@@ -299,7 +300,7 @@ void i2o_driver_notify_device_add_all(st
 	int i;
 	struct i2o_driver *drv;
 
-	for (i = 0; i < I2O_MAX_DRIVERS; i++) {
+	for (i = 0; i < i2o_max_drivers; i++) {
 		drv = i2o_drivers[i];
 
 		if (drv)
@@ -318,7 +319,7 @@ void i2o_driver_notify_device_remove_all
 	int i;
 	struct i2o_driver *drv;
 
-	for (i = 0; i < I2O_MAX_DRIVERS; i++) {
+	for (i = 0; i < i2o_max_drivers; i++) {
 		drv = i2o_drivers[i];
 
 		if (drv)
@@ -340,8 +341,7 @@ int __init i2o_driver_init(void)
 	spin_lock_init(&i2o_drivers_lock);
 
 	if ((i2o_max_drivers < 2) || (i2o_max_drivers > 64) ||
-	    ((i2o_max_drivers ^ (i2o_max_drivers - 1)) !=
-	     (2 * i2o_max_drivers - 1))) {
+	    !is_power_of_2(i2o_max_drivers)) {
 		osm_warn("max_drivers set to %d, but must be >=2 and <= 64 and "
 			 "a power of 2\n", i2o_max_drivers);
 		i2o_max_drivers = I2O_MAX_DRIVERS;
@@ -349,7 +349,7 @@ int __init i2o_driver_init(void)
 	osm_info("max drivers = %d\n", i2o_max_drivers);
 
 	i2o_drivers =
-	    kzalloc(i2o_max_drivers * sizeof(*i2o_drivers), GFP_KERNEL);
+	    kcalloc(i2o_max_drivers, sizeof(*i2o_drivers), GFP_KERNEL);
 	if (!i2o_drivers)
 		return -ENOMEM;
 

^ permalink raw reply	[flat|nested] 3+ messages in thread

* Re: [PATCH] i2o: fix notifiers when max_drivers is configured
  2007-05-20 14:27 [PATCH] i2o: fix notifiers when max_drivers is configured Akinobu Mita
@ 2007-05-21  4:16 ` Andrew Morton
  2007-05-21 16:58   ` Akinobu Mita
  0 siblings, 1 reply; 3+ messages in thread
From: Andrew Morton @ 2007-05-21  4:16 UTC (permalink / raw)
  To: Akinobu Mita; +Cc: Markus Lidel, linux-kernel

On Sun, 20 May 2007 23:27:28 +0900 Akinobu Mita <akinobu.mita@gmail.com> wrote:

> Maxinum number of I2O drivers which could be registered is
> configurable by max_drivers module parameter.
> 
> But the module parameter is ignored and default value (I2O_MAX_DRIVERS = 8)
> is used in the loops to notify all registered drivers.
> 
> Cc: Markus Lidel <Markus.Lidel@shadowconnect.com>
> Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
> 
> ---
>  drivers/message/i2o/driver.c |   14 +++++++-------
>  1 file changed, 7 insertions(+), 7 deletions(-)
> 
> Index: 2.6-mm/drivers/message/i2o/driver.c
> ===================================================================
> --- 2.6-mm.orig/drivers/message/i2o/driver.c
> +++ 2.6-mm/drivers/message/i2o/driver.c
> @@ -20,6 +20,7 @@
>  #include <linux/workqueue.h>
>  #include <linux/string.h>
>  #include <linux/slab.h>
> +#include <linux/log2.h>
>  #include "core.h"
>  
>  #define OSM_NAME	"i2o"
> @@ -260,7 +261,7 @@ void i2o_driver_notify_controller_add_al
>  	int i;
>  	struct i2o_driver *drv;
>  
> -	for (i = 0; i < I2O_MAX_DRIVERS; i++) {
> +	for (i = 0; i < i2o_max_drivers; i++) {
>  		drv = i2o_drivers[i];
>  
>  		if (drv)
> @@ -280,7 +281,7 @@ void i2o_driver_notify_controller_remove
>  	int i;
>  	struct i2o_driver *drv;
>  
> -	for (i = 0; i < I2O_MAX_DRIVERS; i++) {
> +	for (i = 0; i < i2o_max_drivers; i++) {
>  		drv = i2o_drivers[i];
>  
>  		if (drv)
> @@ -299,7 +300,7 @@ void i2o_driver_notify_device_add_all(st
>  	int i;
>  	struct i2o_driver *drv;
>  
> -	for (i = 0; i < I2O_MAX_DRIVERS; i++) {
> +	for (i = 0; i < i2o_max_drivers; i++) {
>  		drv = i2o_drivers[i];
>  
>  		if (drv)
> @@ -318,7 +319,7 @@ void i2o_driver_notify_device_remove_all
>  	int i;
>  	struct i2o_driver *drv;
>  
> -	for (i = 0; i < I2O_MAX_DRIVERS; i++) {
> +	for (i = 0; i < i2o_max_drivers; i++) {
>  		drv = i2o_drivers[i];
>  
>  		if (drv)
> @@ -340,8 +341,7 @@ int __init i2o_driver_init(void)
>  	spin_lock_init(&i2o_drivers_lock);
>  
>  	if ((i2o_max_drivers < 2) || (i2o_max_drivers > 64) ||
> -	    ((i2o_max_drivers ^ (i2o_max_drivers - 1)) !=
> -	     (2 * i2o_max_drivers - 1))) {
> +	    !is_power_of_2(i2o_max_drivers)) {
>  		osm_warn("max_drivers set to %d, but must be >=2 and <= 64 and "
>  			 "a power of 2\n", i2o_max_drivers);
>  		i2o_max_drivers = I2O_MAX_DRIVERS;
> @@ -349,7 +349,7 @@ int __init i2o_driver_init(void)
>  	osm_info("max drivers = %d\n", i2o_max_drivers);
>  
>  	i2o_drivers =
> -	    kzalloc(i2o_max_drivers * sizeof(*i2o_drivers), GFP_KERNEL);
> +	    kcalloc(i2o_max_drivers, sizeof(*i2o_drivers), GFP_KERNEL);
>  	if (!i2o_drivers)
>  		return -ENOMEM;
>  

Is there any particular reason why i2o_max_drivers must be a power of two? 
It seems a peculiar constraint.

^ permalink raw reply	[flat|nested] 3+ messages in thread

* Re: [PATCH] i2o: fix notifiers when max_drivers is configured
  2007-05-21  4:16 ` Andrew Morton
@ 2007-05-21 16:58   ` Akinobu Mita
  0 siblings, 0 replies; 3+ messages in thread
From: Akinobu Mita @ 2007-05-21 16:58 UTC (permalink / raw)
  To: Andrew Morton; +Cc: Markus Lidel, linux-kernel

On Sun, May 20, 2007 at 09:16:59PM -0700, Andrew Morton wrote:
> > @@ -340,8 +341,7 @@ int __init i2o_driver_init(void)
> >  	spin_lock_init(&i2o_drivers_lock);
> >  
> >  	if ((i2o_max_drivers < 2) || (i2o_max_drivers > 64) ||
> > -	    ((i2o_max_drivers ^ (i2o_max_drivers - 1)) !=
> > -	     (2 * i2o_max_drivers - 1))) {
> > +	    !is_power_of_2(i2o_max_drivers)) {
> >  		osm_warn("max_drivers set to %d, but must be >=2 and <= 64 and "
> >  			 "a power of 2\n", i2o_max_drivers);
> >  		i2o_max_drivers = I2O_MAX_DRIVERS;
> 
> Is there any particular reason why i2o_max_drivers must be a power of two? 
> It seems a peculiar constraint.

I can't find the reason.

Subject: [patch -mm] i2o: eliminate a peculiar constraint on i2o_max_drivers

There is no reason i2o_max_drivers must be a power of two.
This patch eliminates such a constraint.

Cc: Markus Lidel <Markus.Lidel@shadowconnect.com>
Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>

---
 drivers/message/i2o/driver.c |    8 +++-----
 1 file changed, 3 insertions(+), 5 deletions(-)

Index: 2.6-mm/drivers/message/i2o/driver.c
===================================================================
--- 2.6-mm.orig/drivers/message/i2o/driver.c
+++ 2.6-mm/drivers/message/i2o/driver.c
@@ -20,7 +20,6 @@
 #include <linux/workqueue.h>
 #include <linux/string.h>
 #include <linux/slab.h>
-#include <linux/log2.h>
 #include "core.h"
 
 #define OSM_NAME	"i2o"
@@ -340,10 +339,9 @@ int __init i2o_driver_init(void)
 
 	spin_lock_init(&i2o_drivers_lock);
 
-	if ((i2o_max_drivers < 2) || (i2o_max_drivers > 64) ||
-	    !is_power_of_2(i2o_max_drivers)) {
-		osm_warn("max_drivers set to %d, but must be >=2 and <= 64 and "
-			 "a power of 2\n", i2o_max_drivers);
+	if ((i2o_max_drivers < 2) || (i2o_max_drivers > 64)) {
+		osm_warn("max_drivers set to %d, but must be >=2 and <= 64\n",
+			 i2o_max_drivers);
 		i2o_max_drivers = I2O_MAX_DRIVERS;
 	}
 	osm_info("max drivers = %d\n", i2o_max_drivers);

^ permalink raw reply	[flat|nested] 3+ messages in thread

end of thread, other threads:[~2007-05-21 17:05 UTC | newest]

Thread overview: 3+ messages (download: mbox.gz follow: Atom feed
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2007-05-20 14:27 [PATCH] i2o: fix notifiers when max_drivers is configured Akinobu Mita
2007-05-21  4:16 ` Andrew Morton
2007-05-21 16:58   ` Akinobu Mita

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