Re: [PATCH/RFC] Add node 'states' sysfs class attribute - V2

[Yasunori Goto <y-goto@jp.fujitsu.com>]

Hi.

> Add a sysfs class attribute file to /sys/devices/system/node
> to display node state masks.

IIRC, sysfs has the policy that each file shows only one value,
and all files keep it.

But, this states file shows 4 values.
I think you should  make 4 files which show just one value like
followings.
  /sys/devices/system/node/possible
                          /online
                          /has_normal_memory
                          /has_cpu

Thanks.

> 
> Signed-off-by:  Lee Schermerhorn <lee.schermerhorn@hp.com>
> 
>  drivers/base/node.c |   71 +++++++++++++++++++++++++++++++++++++++++++++++++++-
>  1 file changed, 70 insertions(+), 1 deletion(-)
> 
> Index: Linux/drivers/base/node.c
> ===================================================================
> --- Linux.orig/drivers/base/node.c	2007-08-27 12:31:32.000000000 -0400
> +++ Linux/drivers/base/node.c	2007-08-27 16:30:18.000000000 -0400
> @@ -12,6 +12,7 @@
>  #include <linux/topology.h>
>  #include <linux/nodemask.h>
>  #include <linux/cpu.h>
> +#include <linux/device.h>
>  
>  static struct sysdev_class node_class = {
>  	set_kset_name("node"),
> @@ -232,8 +233,76 @@ void unregister_one_node(int nid)
>  	unregister_node(&node_devices[nid]);
>  }
>  
> +/*
> + * [node] states attribute
> + */
> +static char * node_state_names[] = {
> +	"possible:",
> +	"on-line:",
> +	"normal memory:",
> +#ifdef CONFIG_HIGHMEM
> +	"high memory:",
> +#endif
> +	"cpu:",
> +};
> +
> +static ssize_t
> +print_node_states(struct class *class, char *buf)
> +{
> +	int i;
> +	int n;
> +	ssize_t  size = PAGE_SIZE;
> +
> +	for (i = 0; i < NR_NODE_STATES; i++) {
> +		n = snprintf(buf, size, "%14s  ", node_state_names[i]);
> +		if (n <= 0)
> +			break;
> +		buf += n;
> +		size -= n;
> +		if (size <= 0)
> +			break;
> +
> +		n = nodelist_scnprintf(buf, size, node_states[i]);
> +		if (n <= 0)
> +			break;
> +		buf += n;
> +		size -=n;
> +		if (size <= 0)
> +			break;
> +
> +		n = snprintf(buf, size, "\n");
> +		if (n <= 0)
> +			break;
> +		buf += n;
> +		size -= n;
> +		if (size <= 0)
> +			break;
> +	}
> +
> +	if (n > 0) {
> +		n = PAGE_SIZE;
> +		if (size > 0)
> +			n -= size;
> +	}
> +	return n;
> +}
> +
> +static CLASS_ATTR(states, 0444, print_node_states, NULL);
> +
> +static int node_states_init(void)
> +{
> +	return sysfs_create_file(&node_class.kset.kobj,
> +				&class_attr_states.attr);
> +}
> +
>  static int __init register_node_type(void)
>  {
> -	return sysdev_class_register(&node_class);
> +	int ret;
> +
> +	ret = sysdev_class_register(&node_class);
> +	if (!ret)
> +		ret = node_states_init();
> +
> +	return ret;
>  }
>  postcore_initcall(register_node_type);
> 

-- 
Yasunori Goto 


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