diff mbox series

[-next] mm/damon/paddr: minor refactor of damon_pa_pageout()

Message ID 20230302144926.40012-1-wangkefeng.wang@huawei.com
State New
Headers
Series [-next] mm/damon/paddr: minor refactor of damon_pa_pageout() |

Commit Message

Kefeng Wang March 2, 2023, 2:49 p.m. UTC 
  Omit two lines by converting if(!folio_isolate_lru()) to
if(folio_isolate_lru()).

Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
---
 mm/damon/paddr.c | 12 +++++-------
 1 file changed, 5 insertions(+), 7 deletions(-)

Comments

SeongJae Park March 2, 2023, 4:47 p.m. UTC | #1 
Hi Kefeng,

On Thu, 2 Mar 2023 22:49:26 +0800 Kefeng Wang <wangkefeng.wang@huawei.com> wrote:

> Omit two lines by converting if(!folio_isolate_lru()) to
> if(folio_isolate_lru()).
> 
> Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
> ---
>  mm/damon/paddr.c | 12 +++++-------
>  1 file changed, 5 insertions(+), 7 deletions(-)
> 
> diff --git a/mm/damon/paddr.c b/mm/damon/paddr.c
> index 6c655d9b5639..a557f3c9300f 100644
> --- a/mm/damon/paddr.c
> +++ b/mm/damon/paddr.c
> @@ -246,14 +246,12 @@ static unsigned long damon_pa_pageout(struct damon_region *r, struct damos *s)
>  
>  		folio_clear_referenced(folio);
>  		folio_test_clear_young(folio);
> -		if (!folio_isolate_lru(folio)) {
> -			folio_put(folio);
> -			continue;
> +		if (folio_isolate_lru(folio)) {
> +			if (folio_test_unevictable(folio))
> +				folio_putback_lru(folio);
> +			else
> +				list_add(&folio->lru, &folio_list);
>  		}
> -		if (folio_test_unevictable(folio))
> -			folio_putback_lru(folio);
> -		else
> -			list_add(&folio->lru, &folio_list);
>  		folio_put(folio);
>  	}

This looks ok to me, thank you for your effort!  Nevertheless, I don't like
increasing depth as much as number of lines.  The
more-than-3-levels-of-indentation[1] warning is not always right, but this 4
levels of indentation is not making me so exciting.

What do you think about adding put_continue label and using it, not only here,
but also above part?  For example:

    --- a/mm/damon/paddr.c
    +++ b/mm/damon/paddr.c
    @@ -239,21 +239,18 @@ static unsigned long damon_pa_pageout(struct damon_region *r, struct damos *s)
                    if (!folio)
                            continue;
    
    -               if (damos_pa_filter_out(s, folio)) {
    -                       folio_put(folio);
    -                       continue;
    -               }
    +               if (damos_pa_filter_out(s, folio))
    +                       goto put_continue;
    
                    folio_clear_referenced(folio);
                    folio_test_clear_young(folio);
    -               if (!folio_isolate_lru(folio)) {
    -                       folio_put(folio);
    -                       continue;
    -               }
    +               if (!folio_isolate_lru(folio))
    +                       goto put_continue;
                    if (folio_test_unevictable(folio))
                            folio_putback_lru(folio);
                    else
                            list_add(&folio->lru, &folio_list);
    +put_continue:
                    folio_put(folio);
            }
            applied = reclaim_pages(&folio_list);

It omits three lines.

    $ git diff --stat
     mm/damon/paddr.c | 13 +++++--------
     1 file changed, 5 insertions(+), 8 deletions(-)

[1] https://docs.kernel.org/process/coding-style.html#indentation


Thanks,
SJ

>  	applied = reclaim_pages(&folio_list);
> -- 
> 2.35.3
> 
>
Kefeng Wang March 3, 2023, 1:42 a.m. UTC | #2 
On 2023/3/3 0:47, SeongJae Park wrote:
> Hi Kefeng,
> 
> On Thu, 2 Mar 2023 22:49:26 +0800 Kefeng Wang <wangkefeng.wang@huawei.com> wrote:
> 
>> Omit two lines by converting if(!folio_isolate_lru()) to
>> if(folio_isolate_lru()).
>>
>> Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
>> ---
>>   mm/damon/paddr.c | 12 +++++-------
>>   1 file changed, 5 insertions(+), 7 deletions(-)
>>
>> diff --git a/mm/damon/paddr.c b/mm/damon/paddr.c
>> index 6c655d9b5639..a557f3c9300f 100644
>> --- a/mm/damon/paddr.c
>> +++ b/mm/damon/paddr.c
>> @@ -246,14 +246,12 @@ static unsigned long damon_pa_pageout(struct damon_region *r, struct damos *s)
>>   
>>   		folio_clear_referenced(folio);
>>   		folio_test_clear_young(folio);
>> -		if (!folio_isolate_lru(folio)) {
>> -			folio_put(folio);
>> -			continue;
>> +		if (folio_isolate_lru(folio)) {
>> +			if (folio_test_unevictable(folio))
>> +				folio_putback_lru(folio);
>> +			else
>> +				list_add(&folio->lru, &folio_list);
>>   		}
>> -		if (folio_test_unevictable(folio))
>> -			folio_putback_lru(folio);
>> -		else
>> -			list_add(&folio->lru, &folio_list);
>>   		folio_put(folio);
>>   	}
> 
> This looks ok to me, thank you for your effort!  Nevertheless, I don't like
> increasing depth as much as number of lines.  The
> more-than-3-levels-of-indentation[1] warning is not always right, but this 4
> levels of indentation is not making me so exciting.
> 
> What do you think about adding put_continue label and using it, not only here,
> but also above part?  For example:
> 
>      --- a/mm/damon/paddr.c
>      +++ b/mm/damon/paddr.c
>      @@ -239,21 +239,18 @@ static unsigned long damon_pa_pageout(struct damon_region *r, struct damos *s)
>                      if (!folio)
>                              continue;
>      
>      -               if (damos_pa_filter_out(s, folio)) {
>      -                       folio_put(folio);
>      -                       continue;
>      -               }
>      +               if (damos_pa_filter_out(s, folio))
>      +                       goto put_continue;
>      
>                      folio_clear_referenced(folio);
>                      folio_test_clear_young(folio);
>      -               if (!folio_isolate_lru(folio)) {
>      -                       folio_put(folio);
>      -                       continue;
>      -               }
>      +               if (!folio_isolate_lru(folio))
>      +                       goto put_continue;
>                      if (folio_test_unevictable(folio))
>                              folio_putback_lru(folio);
>                      else
>                              list_add(&folio->lru, &folio_list);
>      +put_continue:
>                      folio_put(folio);
>              }
>              applied = reclaim_pages(&folio_list);
> 
> It omits three lines.

It looks good, will update, thanks

> 
>      $ git diff --stat
>       mm/damon/paddr.c | 13 +++++--------
>       1 file changed, 5 insertions(+), 8 deletions(-)
> 
> [1] https://docs.kernel.org/process/coding-style.html#indentation
> 
> 
> Thanks,
> SJ
> 
>>   	applied = reclaim_pages(&folio_list);
>> -- 
>> 2.35.3
>>
>>
diff mbox series

Patch

diff --git a/mm/damon/paddr.c b/mm/damon/paddr.c
index 6c655d9b5639..a557f3c9300f 100644
--- a/mm/damon/paddr.c
+++ b/mm/damon/paddr.c
@@ -246,14 +246,12 @@  static unsigned long damon_pa_pageout(struct damon_region *r, struct damos *s)
 
 		folio_clear_referenced(folio);
 		folio_test_clear_young(folio);
-		if (!folio_isolate_lru(folio)) {
-			folio_put(folio);
-			continue;
+		if (folio_isolate_lru(folio)) {
+			if (folio_test_unevictable(folio))
+				folio_putback_lru(folio);
+			else
+				list_add(&folio->lru, &folio_list);
 		}
-		if (folio_test_unevictable(folio))
-			folio_putback_lru(folio);
-		else
-			list_add(&folio->lru, &folio_list);
 		folio_put(folio);
 	}
 	applied = reclaim_pages(&folio_list);