diff mbox series

mm/memory_hotplug: use helper function zone_end_pfn() to get end_pfn

Message ID 20210127093211.37714-1-linmiaohe@huawei.com (mailing list archive)
State New
Headers show
Series mm/memory_hotplug: use helper function zone_end_pfn() to get end_pfn | expand

Commit Message

Miaohe Lin Jan. 27, 2021, 9:32 a.m. UTC
Commit 108bcc96ef70 ("mm: add & use zone_end_pfn() and zone_spans_pfn()")
introduced the helper zone_end_pfn() to calculate the zone end pfn.  But
update_pgdat_span() forgot to use it. Use this helper and re-name local
variable zone_end_pfn to end_pfn to fix below compilation error:

mm/memory_hotplug.c: In function ‘update_pgdat_span’:
mm/memory_hotplug.c:448:32: error: called object ‘zone_end_pfn’ is not a
function or function pointer
   unsigned long zone_end_pfn = zone_end_pfn(zone);
                                ^~~~~~~~~~~~
mm/memory_hotplug.c:448:17: note: declared here
   unsigned long zone_end_pfn = zone_end_pfn(zone);
                 ^~~~~~~~~~~~

Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
---
 mm/memory_hotplug.c | 9 ++++-----
 1 file changed, 4 insertions(+), 5 deletions(-)

Comments

David Hildenbrand Jan. 27, 2021, 9:40 a.m. UTC | #1
On 27.01.21 10:32, Miaohe Lin wrote:
> Commit 108bcc96ef70 ("mm: add & use zone_end_pfn() and zone_spans_pfn()")
> introduced the helper zone_end_pfn() to calculate the zone end pfn.  But
> update_pgdat_span() forgot to use it. Use this helper and re-name local
> variable zone_end_pfn to end_pfn to fix below compilation error:
> 
> mm/memory_hotplug.c: In function ‘update_pgdat_span’:
> mm/memory_hotplug.c:448:32: error: called object ‘zone_end_pfn’ is not a
> function or function pointer
>     unsigned long zone_end_pfn = zone_end_pfn(zone);
>                                  ^~~~~~~~~~~~
> mm/memory_hotplug.c:448:17: note: declared here
>     unsigned long zone_end_pfn = zone_end_pfn(zone);
>                   ^~~~~~~~~~~~
> 

Please don't talk about compilation issues your changes introduce in 
that detail, that's just confusing and looks like something would 
already be broken. Please simplify to something like

"Let's use zone_end_pfn(zone). We have to rename the local variable to 
avoid an identifier clash (variable vs. function)."

With that

Reviewed-by: David Hildenbrand <david@redhat.com>

> Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
> ---
>   mm/memory_hotplug.c | 9 ++++-----
>   1 file changed, 4 insertions(+), 5 deletions(-)
> 
> diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c
> index 710e469fb3a1..0483db52b85f 100644
> --- a/mm/memory_hotplug.c
> +++ b/mm/memory_hotplug.c
> @@ -493,20 +493,19 @@ static void update_pgdat_span(struct pglist_data *pgdat)
>   
>   	for (zone = pgdat->node_zones;
>   	     zone < pgdat->node_zones + MAX_NR_ZONES; zone++) {
> -		unsigned long zone_end_pfn = zone->zone_start_pfn +
> -					     zone->spanned_pages;
> +		unsigned long end_pfn = zone_end_pfn(zone);
>   
>   		/* No need to lock the zones, they can't change. */
>   		if (!zone->spanned_pages)
>   			continue;
>   		if (!node_end_pfn) {
>   			node_start_pfn = zone->zone_start_pfn;
> -			node_end_pfn = zone_end_pfn;
> +			node_end_pfn = end_pfn;
>   			continue;
>   		}
>   
> -		if (zone_end_pfn > node_end_pfn)
> -			node_end_pfn = zone_end_pfn;
> +		if (end_pfn > node_end_pfn)
> +			node_end_pfn = end_pfn;
>   		if (zone->zone_start_pfn < node_start_pfn)
>   			node_start_pfn = zone->zone_start_pfn;
>   	}
>
Miaohe Lin Jan. 28, 2021, 1:58 a.m. UTC | #2
Hi:
On 2021/1/27 17:40, David Hildenbrand wrote:
> On 27.01.21 10:32, Miaohe Lin wrote:
>> Commit 108bcc96ef70 ("mm: add & use zone_end_pfn() and zone_spans_pfn()")
>> introduced the helper zone_end_pfn() to calculate the zone end pfn.  But
>> update_pgdat_span() forgot to use it. Use this helper and re-name local
>> variable zone_end_pfn to end_pfn to fix below compilation error:
>>
>> mm/memory_hotplug.c: In function ‘update_pgdat_span’:
>> mm/memory_hotplug.c:448:32: error: called object ‘zone_end_pfn’ is not a
>> function or function pointer
>>     unsigned long zone_end_pfn = zone_end_pfn(zone);
>>                                  ^~~~~~~~~~~~
>> mm/memory_hotplug.c:448:17: note: declared here
>>     unsigned long zone_end_pfn = zone_end_pfn(zone);
>>                   ^~~~~~~~~~~~
>>
> 
> Please don't talk about compilation issues your changes introduce in that detail, that's just confusing and looks like something would already be broken. Please simplify to something like

I will keep this in mind. Thanks.

> 
> "Let's use zone_end_pfn(zone). We have to rename the local variable to avoid an identifier clash (variable vs. function)."
> 
> With that
> 
> Reviewed-by: David Hildenbrand <david@redhat.com>
> 

Many thanks for review and reply.

>> Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
>> ---
>>   mm/memory_hotplug.c | 9 ++++-----
>>   1 file changed, 4 insertions(+), 5 deletions(-)
>>
>> diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c
>> index 710e469fb3a1..0483db52b85f 100644
>> --- a/mm/memory_hotplug.c
>> +++ b/mm/memory_hotplug.c
>> @@ -493,20 +493,19 @@ static void update_pgdat_span(struct pglist_data *pgdat)
>>         for (zone = pgdat->node_zones;
>>            zone < pgdat->node_zones + MAX_NR_ZONES; zone++) {
>> -        unsigned long zone_end_pfn = zone->zone_start_pfn +
>> -                         zone->spanned_pages;
>> +        unsigned long end_pfn = zone_end_pfn(zone);
>>             /* No need to lock the zones, they can't change. */
>>           if (!zone->spanned_pages)
>>               continue;
>>           if (!node_end_pfn) {
>>               node_start_pfn = zone->zone_start_pfn;
>> -            node_end_pfn = zone_end_pfn;
>> +            node_end_pfn = end_pfn;
>>               continue;
>>           }
>>   -        if (zone_end_pfn > node_end_pfn)
>> -            node_end_pfn = zone_end_pfn;
>> +        if (end_pfn > node_end_pfn)
>> +            node_end_pfn = end_pfn;
>>           if (zone->zone_start_pfn < node_start_pfn)
>>               node_start_pfn = zone->zone_start_pfn;
>>       }
>>
> 
>
diff mbox series

Patch

diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c
index 710e469fb3a1..0483db52b85f 100644
--- a/mm/memory_hotplug.c
+++ b/mm/memory_hotplug.c
@@ -493,20 +493,19 @@  static void update_pgdat_span(struct pglist_data *pgdat)
 
 	for (zone = pgdat->node_zones;
 	     zone < pgdat->node_zones + MAX_NR_ZONES; zone++) {
-		unsigned long zone_end_pfn = zone->zone_start_pfn +
-					     zone->spanned_pages;
+		unsigned long end_pfn = zone_end_pfn(zone);
 
 		/* No need to lock the zones, they can't change. */
 		if (!zone->spanned_pages)
 			continue;
 		if (!node_end_pfn) {
 			node_start_pfn = zone->zone_start_pfn;
-			node_end_pfn = zone_end_pfn;
+			node_end_pfn = end_pfn;
 			continue;
 		}
 
-		if (zone_end_pfn > node_end_pfn)
-			node_end_pfn = zone_end_pfn;
+		if (end_pfn > node_end_pfn)
+			node_end_pfn = end_pfn;
 		if (zone->zone_start_pfn < node_start_pfn)
 			node_start_pfn = zone->zone_start_pfn;
 	}