Re: [PATCH v3] drivers/base/memory: simplify outputting of valid_zones_show()

[David Hildenbrand <david@redhat.com>]

On 22.01.25 11:14, Shiyang Ruan wrote:
> Hi,
> 
> ping~
> Any other comments?  Thanks.
> 

Hi,

you should always CC Andrew.

@Andrew: 
https://lkml.kernel.org/r/20250108015223.1522887-1-ruansy.fnst@fujitsu.com

> 
> 在 2025/1/8 9:52, Shiyang Ruan 写道:
>> No need to specific position at the first writing to the buf because the
>> @len is always 0 at this time.  Use sysfs_emit() instead to simplify it.
>> Also avoid setting/checking default_zone with a conditional operator.
>>
>> Signed-off-by: Shiyang Ruan <ruansy.fnst@fujitsu.com>
>> Acked-by: David Hildenbrand <david@redhat.com>
>> ---
>>    drivers/base/memory.c | 12 ++++--------
>>    1 file changed, 4 insertions(+), 8 deletions(-)
>>
>> diff --git a/drivers/base/memory.c b/drivers/base/memory.c
>> index 67858eeb92ed..92e6bc6eb21e 100644
>> --- a/drivers/base/memory.c
>> +++ b/drivers/base/memory.c
>> @@ -455,7 +455,7 @@ static ssize_t valid_zones_show(struct device *dev,
>>    	struct memory_group *group = mem->group;
>>    	struct zone *default_zone;
>>    	int nid = mem->nid;
>> -	int len = 0;
>> +	int len;
>>    
>>    	/*
>>    	 * Check the existing zone. Make sure that we do that only on the
>> @@ -466,22 +466,18 @@ static ssize_t valid_zones_show(struct device *dev,
>>    		 * If !mem->zone, the memory block spans multiple zones and
>>    		 * cannot get offlined.
>>    		 */
>> -		default_zone = mem->zone;
>> -		if (!default_zone)
>> -			return sysfs_emit(buf, "%s\n", "none");
>> -		len += sysfs_emit_at(buf, len, "%s", default_zone->name);
>> -		goto out;
>> +		return sysfs_emit(buf, "%s\n",
>> +				  mem->zone ? mem->zone->name : "none");
>>    	}
>>    
>>    	default_zone = zone_for_pfn_range(MMOP_ONLINE, nid, group,
>>    					  start_pfn, nr_pages);
>>    
>> -	len += sysfs_emit_at(buf, len, "%s", default_zone->name);
>> +	len = sysfs_emit(buf, "%s", default_zone->name);
>>    	len += print_allowed_zone(buf, len, nid, group, start_pfn, nr_pages,
>>    				  MMOP_ONLINE_KERNEL, default_zone);
>>    	len += print_allowed_zone(buf, len, nid, group, start_pfn, nr_pages,
>>    				  MMOP_ONLINE_MOVABLE, default_zone);
>> -out:
>>    	len += sysfs_emit_at(buf, len, "\n");
>>    	return len;
>>    }
> 


-- 
Cheers,

David / dhildenb