[v2,2/4] mm/page_alloc.c: bad_[reason|flags] is not necessary when PageHWPoison
diff mbox series

Message ID 20200120030415.15925-3-richardw.yang@linux.intel.com
State New
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Series
  • mm/page_alloc.c: cleanup on check page
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Commit Message

Wei Yang Jan. 20, 2020, 3:04 a.m. UTC
Since function returns directly, bad_[reason|flags] is not used any
where.

This is a following cleanup for commit e570f56cccd21 ("mm:
check_new_page_bad() directly returns in __PG_HWPOISON case")

Signed-off-by: Wei Yang <richardw.yang@linux.intel.com>
Acked-by: David Rientjes <rientjes@google.com>
---
 mm/page_alloc.c | 2 --
 1 file changed, 2 deletions(-)

Comments

Anshuman Khandual Jan. 20, 2020, 6:28 a.m. UTC | #1
On 01/20/2020 08:34 AM, Wei Yang wrote:
> Since function returns directly, bad_[reason|flags] is not used any
> where.
> 
> This is a following cleanup for commit e570f56cccd21 ("mm:
> check_new_page_bad() directly returns in __PG_HWPOISON case")
> 
> Signed-off-by: Wei Yang <richardw.yang@linux.intel.com>
> Acked-by: David Rientjes <rientjes@google.com>
> ---
>  mm/page_alloc.c | 2 --
>  1 file changed, 2 deletions(-)
> 
> diff --git a/mm/page_alloc.c b/mm/page_alloc.c
> index 0cf6218aaba7..a43b9d2482f2 100644
> --- a/mm/page_alloc.c
> +++ b/mm/page_alloc.c
> @@ -2051,8 +2051,6 @@ static void check_new_page_bad(struct page *page)
>  	if (unlikely(page_ref_count(page) != 0))
>  		bad_reason = "nonzero _refcount";
>  	if (unlikely(page->flags & __PG_HWPOISON)) {
> -		bad_reason = "HWPoisoned (hardware-corrupted)";
> -		bad_flags = __PG_HWPOISON;
>  		/* Don't complain about hwpoisoned pages */
>  		page_mapcount_reset(page); /* remove PageBuddy */
>  		return;

This bail out condition should be the first in the function
check_new_page_bad() before evaluating bad_[reason|flags]
as they will never be used.

>
Michal Hocko Jan. 20, 2020, 10:17 a.m. UTC | #2
On Mon 20-01-20 11:04:13, Wei Yang wrote:
> Since function returns directly, bad_[reason|flags] is not used any
> where.
> 
> This is a following cleanup for commit e570f56cccd21 ("mm:
> check_new_page_bad() directly returns in __PG_HWPOISON case")
> 
> Signed-off-by: Wei Yang <richardw.yang@linux.intel.com>
> Acked-by: David Rientjes <rientjes@google.com>

This is a left over from loong time ago. AFAICS bad_reason and flags hav
never been used.

Acked-by: Michal Hocko <mhocko@suse.com>

> ---
>  mm/page_alloc.c | 2 --
>  1 file changed, 2 deletions(-)
> 
> diff --git a/mm/page_alloc.c b/mm/page_alloc.c
> index 0cf6218aaba7..a43b9d2482f2 100644
> --- a/mm/page_alloc.c
> +++ b/mm/page_alloc.c
> @@ -2051,8 +2051,6 @@ static void check_new_page_bad(struct page *page)
>  	if (unlikely(page_ref_count(page) != 0))
>  		bad_reason = "nonzero _refcount";
>  	if (unlikely(page->flags & __PG_HWPOISON)) {
> -		bad_reason = "HWPoisoned (hardware-corrupted)";
> -		bad_flags = __PG_HWPOISON;
>  		/* Don't complain about hwpoisoned pages */
>  		page_mapcount_reset(page); /* remove PageBuddy */
>  		return;
> -- 
> 2.17.1
Wei Yang Jan. 20, 2020, 12:13 p.m. UTC | #3
On Mon, Jan 20, 2020 at 11:58:04AM +0530, Anshuman Khandual wrote:
>
>
>On 01/20/2020 08:34 AM, Wei Yang wrote:
>> Since function returns directly, bad_[reason|flags] is not used any
>> where.
>> 
>> This is a following cleanup for commit e570f56cccd21 ("mm:
>> check_new_page_bad() directly returns in __PG_HWPOISON case")
>> 
>> Signed-off-by: Wei Yang <richardw.yang@linux.intel.com>
>> Acked-by: David Rientjes <rientjes@google.com>
>> ---
>>  mm/page_alloc.c | 2 --
>>  1 file changed, 2 deletions(-)
>> 
>> diff --git a/mm/page_alloc.c b/mm/page_alloc.c
>> index 0cf6218aaba7..a43b9d2482f2 100644
>> --- a/mm/page_alloc.c
>> +++ b/mm/page_alloc.c
>> @@ -2051,8 +2051,6 @@ static void check_new_page_bad(struct page *page)
>>  	if (unlikely(page_ref_count(page) != 0))
>>  		bad_reason = "nonzero _refcount";
>>  	if (unlikely(page->flags & __PG_HWPOISON)) {
>> -		bad_reason = "HWPoisoned (hardware-corrupted)";
>> -		bad_flags = __PG_HWPOISON;
>>  		/* Don't complain about hwpoisoned pages */
>>  		page_mapcount_reset(page); /* remove PageBuddy */
>>  		return;
>
>This bail out condition should be the first in the function
>check_new_page_bad() before evaluating bad_[reason|flags]
>as they will never be used.
>

This is reasonable.

>>
David Hildenbrand Jan. 20, 2020, 12:20 p.m. UTC | #4
On 20.01.20 04:04, Wei Yang wrote:
> Since function returns directly, bad_[reason|flags] is not used any
> where.
> 
> This is a following cleanup for commit e570f56cccd21 ("mm:
> check_new_page_bad() directly returns in __PG_HWPOISON case")
> 
> Signed-off-by: Wei Yang <richardw.yang@linux.intel.com>
> Acked-by: David Rientjes <rientjes@google.com>
> ---
>  mm/page_alloc.c | 2 --
>  1 file changed, 2 deletions(-)
> 
> diff --git a/mm/page_alloc.c b/mm/page_alloc.c
> index 0cf6218aaba7..a43b9d2482f2 100644
> --- a/mm/page_alloc.c
> +++ b/mm/page_alloc.c
> @@ -2051,8 +2051,6 @@ static void check_new_page_bad(struct page *page)
>  	if (unlikely(page_ref_count(page) != 0))
>  		bad_reason = "nonzero _refcount";
>  	if (unlikely(page->flags & __PG_HWPOISON)) {
> -		bad_reason = "HWPoisoned (hardware-corrupted)";
> -		bad_flags = __PG_HWPOISON;
>  		/* Don't complain about hwpoisoned pages */
>  		page_mapcount_reset(page); /* remove PageBuddy */
>  		return;
> 

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

Patch
diff mbox series

diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 0cf6218aaba7..a43b9d2482f2 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -2051,8 +2051,6 @@  static void check_new_page_bad(struct page *page)
 	if (unlikely(page_ref_count(page) != 0))
 		bad_reason = "nonzero _refcount";
 	if (unlikely(page->flags & __PG_HWPOISON)) {
-		bad_reason = "HWPoisoned (hardware-corrupted)";
-		bad_flags = __PG_HWPOISON;
 		/* Don't complain about hwpoisoned pages */
 		page_mapcount_reset(page); /* remove PageBuddy */
 		return;