[v2,1/1] mm/page_isolation: fix clang deadcode warning

Message ID 20221021051936.15346-2-quic_aiquny@quicinc.com
State New
Headers
Series mm/page_isolation: fix clang deadcode warning |

Commit Message

Aiqun Yu (Maria) Oct. 21, 2022, 5:19 a.m. UTC
  When !CONFIG_VM_BUG_ON, there is warning of
clang-analyzer-deadcode.DeadStores:
Value stored to 'mt' during its initialization
is never read.

Signed-off-by: Maria Yu <quic_aiquny@quicinc.com>
---
 mm/page_isolation.c | 5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)
  

Comments

David Hildenbrand Oct. 21, 2022, 6:54 a.m. UTC | #1
On 21.10.22 07:19, Maria Yu wrote:
> When !CONFIG_VM_BUG_ON, there is warning of
> clang-analyzer-deadcode.DeadStores:
> Value stored to 'mt' during its initialization
> is never read.
> 
> Signed-off-by: Maria Yu <quic_aiquny@quicinc.com>
> ---
>   mm/page_isolation.c | 5 ++---
>   1 file changed, 2 insertions(+), 3 deletions(-)
> 
> diff --git a/mm/page_isolation.c b/mm/page_isolation.c
> index 04141a9bea70..a7a478a22123 100644
> --- a/mm/page_isolation.c
> +++ b/mm/page_isolation.c
> @@ -330,9 +330,8 @@ static int isolate_single_pageblock(unsigned long boundary_pfn, int flags,
>   				      zone->zone_start_pfn);
>   
>   	if (skip_isolation) {
> -		int mt = get_pageblock_migratetype(pfn_to_page(isolate_pageblock));

__maybe_unused should work as well. Was that considered?
  
Aiqun Yu (Maria) Oct. 21, 2022, 8:21 a.m. UTC | #2
On 10/21/2022 2:54 PM, David Hildenbrand wrote:
> On 21.10.22 07:19, Maria Yu wrote:
>> When !CONFIG_VM_BUG_ON, there is warning of
>> clang-analyzer-deadcode.DeadStores:
>> Value stored to 'mt' during its initialization
>> is never read.
>>
>> Signed-off-by: Maria Yu <quic_aiquny@quicinc.com>
>> ---
>>   mm/page_isolation.c | 5 ++---
>>   1 file changed, 2 insertions(+), 3 deletions(-)
>>
>> diff --git a/mm/page_isolation.c b/mm/page_isolation.c
>> index 04141a9bea70..a7a478a22123 100644
>> --- a/mm/page_isolation.c
>> +++ b/mm/page_isolation.c
>> @@ -330,9 +330,8 @@ static int isolate_single_pageblock(unsigned long 
>> boundary_pfn, int flags,
>>                         zone->zone_start_pfn);
>>       if (skip_isolation) {
>> -        int mt = 
>> get_pageblock_migratetype(pfn_to_page(isolate_pageblock));
> 
> __maybe_unused should work as well. Was that considered?
> 
good idea.
  

Patch

diff --git a/mm/page_isolation.c b/mm/page_isolation.c
index 04141a9bea70..a7a478a22123 100644
--- a/mm/page_isolation.c
+++ b/mm/page_isolation.c
@@ -330,9 +330,8 @@  static int isolate_single_pageblock(unsigned long boundary_pfn, int flags,
 				      zone->zone_start_pfn);
 
 	if (skip_isolation) {
-		int mt = get_pageblock_migratetype(pfn_to_page(isolate_pageblock));
-
-		VM_BUG_ON(!is_migrate_isolate(mt));
+		VM_BUG_ON(!is_migrate_isolate(get_pageblock_migratetype(
+						pfn_to_page(isolate_pageblock))));
 	} else {
 		ret = set_migratetype_isolate(pfn_to_page(isolate_pageblock), migratetype,
 				flags, isolate_pageblock, isolate_pageblock + pageblock_nr_pages);