Re: [PATCH 03/18] powerpc/numa: remove ability to enable topology updates

[Srikar Dronamraju <srikar@linux.vnet.ibm.com>]

* Nathan Lynch <nathanl@linux.ibm.com> [2020-06-12 00:12:23]:

> Remove the /proc/powerpc/topology_updates interface and the
> topology_updates=on/off command line argument. The internal
> topology_updates_enabled flag remains for now, but always false.
> 

Looks good to me.

Reviewed-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>

> Signed-off-by: Nathan Lynch <nathanl@linux.ibm.com>
> ---
>  arch/powerpc/mm/numa.c | 71 +-----------------------------------------
>  1 file changed, 1 insertion(+), 70 deletions(-)
> 
> diff --git a/arch/powerpc/mm/numa.c b/arch/powerpc/mm/numa.c
> index 9fcf2d195830..34d95de77bdd 100644
> --- a/arch/powerpc/mm/numa.c
> +++ b/arch/powerpc/mm/numa.c
> @@ -984,27 +984,7 @@ static int __init early_numa(char *p)
>  }
>  early_param("numa", early_numa);
> 
> -/*
> - * The platform can inform us through one of several mechanisms
> - * (post-migration device tree updates, PRRN or VPHN) that the NUMA
> - * assignment of a resource has changed. This controls whether we act
> - * on that. Disabled by default.
> - */
> -static bool topology_updates_enabled;
> -
> -static int __init early_topology_updates(char *p)
> -{
> -	if (!p)
> -		return 0;
> -
> -	if (!strcmp(p, "on")) {
> -		pr_warn("Caution: enabling topology updates\n");
> -		topology_updates_enabled = true;
> -	}
> -
> -	return 0;
> -}
> -early_param("topology_updates", early_topology_updates);
> +static const bool topology_updates_enabled;
> 
>  #ifdef CONFIG_MEMORY_HOTPLUG
>  /*
> @@ -1632,52 +1612,6 @@ int prrn_is_enabled(void)
>  	return prrn_enabled;
>  }
> 
> -static int topology_read(struct seq_file *file, void *v)
> -{
> -	if (vphn_enabled || prrn_enabled)
> -		seq_puts(file, "on\n");
> -	else
> -		seq_puts(file, "off\n");
> -
> -	return 0;
> -}
> -
> -static int topology_open(struct inode *inode, struct file *file)
> -{
> -	return single_open(file, topology_read, NULL);
> -}
> -
> -static ssize_t topology_write(struct file *file, const char __user *buf,
> -			      size_t count, loff_t *off)
> -{
> -	char kbuf[4]; /* "on" or "off" plus null. */
> -	int read_len;
> -
> -	read_len = count < 3 ? count : 3;
> -	if (copy_from_user(kbuf, buf, read_len))
> -		return -EINVAL;
> -
> -	kbuf[read_len] = '\0';
> -
> -	if (!strncmp(kbuf, "on", 2)) {
> -		topology_updates_enabled = true;
> -		start_topology_update();
> -	} else if (!strncmp(kbuf, "off", 3)) {
> -		stop_topology_update();
> -		topology_updates_enabled = false;
> -	} else
> -		return -EINVAL;
> -
> -	return count;
> -}
> -
> -static const struct proc_ops topology_proc_ops = {
> -	.proc_read	= seq_read,
> -	.proc_write	= topology_write,
> -	.proc_open	= topology_open,
> -	.proc_release	= single_release,
> -};
> -
>  static int topology_update_init(void)
>  {
>  	start_topology_update();
> @@ -1685,9 +1619,6 @@ static int topology_update_init(void)
>  	if (vphn_enabled)
>  		topology_schedule_update();
> 
> -	if (!proc_create("powerpc/topology_updates", 0644, NULL, &topology_proc_ops))
> -		return -ENOMEM;
> -
>  	topology_inited = 1;
>  	return 0;
>  }
> -- 
> 2.25.4
> 

-- 
Thanks and Regards
Srikar Dronamraju