[PATCH] f2fs: continue to do fg_gc even if beyond max_victim_search

[PATCH] f2fs: continue to do fg_gc even if beyond max_victim_search

[Yunlei He]

For forground gc, if can't find a victim in one max_victim_search,
try it again.

Signed-off-by: Yunlei He <heyunlei@huawei.com>
---
 fs/f2fs/gc.c | 23 ++++++++++++-----------
 1 file changed, 12 insertions(+), 11 deletions(-)

diff --git a/fs/f2fs/gc.c b/fs/f2fs/gc.c
index 24acbbb..19e51a5 100644
--- a/fs/f2fs/gc.c
+++ b/fs/f2fs/gc.c
@@ -916,24 +916,25 @@ gc_more:
 		goto stop;
 	}
 
-	if (gc_type == BG_GC && has_not_enough_free_secs(sbi, sec_freed, 0)) {
-		gc_type = FG_GC;
+	if (gc_type == BG_GC && has_not_enough_free_secs(sbi, 0, 0)) {
 		/*
 		 * If there is no victim and no prefree segment but still not
 		 * enough free sections, we should flush dent/node blocks and do
 		 * garbage collections.
 		 */
-		if (__get_victim(sbi, &segno, gc_type) ||
-						prefree_segments(sbi)) {
-			write_checkpoint(sbi, &cpc);
-			segno = NULL_SEGNO;
-		} else if (has_not_enough_free_secs(sbi, 0, 0)) {
-			write_checkpoint(sbi, &cpc);
-		}
+		gc_type = FG_GC;
+		write_checkpoint(sbi, &cpc);
 	}
 
-	if (segno == NULL_SEGNO && !__get_victim(sbi, &segno, gc_type))
-		goto stop;
+	if (!__get_victim(sbi, &segno, gc_type)) {
+		if (sync)
+			goto stop;
+		else if (gc_type == FG_GC
+				&& has_not_enough_free_secs(sbi, sec_freed, 0))
+			goto gc_more;
+		else
+			goto stop;
+	}
 	ret = 0;
 
 	if (do_garbage_collect(sbi, segno, &gc_list, gc_type) &&
-- 
1.9.1


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Re: [PATCH] f2fs: continue to do fg_gc even if beyond max_victim_search

[Chao Yu]

On 2016/9/22 11:48, Yunlei He wrote:
> For forground gc, if can't find a victim in one max_victim_search,
> try it again.
> 
> Signed-off-by: Yunlei He <heyunlei@huawei.com>
> ---
>  fs/f2fs/gc.c | 23 ++++++++++++-----------
>  1 file changed, 12 insertions(+), 11 deletions(-)
> 
> diff --git a/fs/f2fs/gc.c b/fs/f2fs/gc.c
> index 24acbbb..19e51a5 100644
> --- a/fs/f2fs/gc.c
> +++ b/fs/f2fs/gc.c
> @@ -916,24 +916,25 @@ gc_more:
>  		goto stop;
>  	}
>  
> -	if (gc_type == BG_GC && has_not_enough_free_secs(sbi, sec_freed, 0)) {
> -		gc_type = FG_GC;
> +	if (gc_type == BG_GC && has_not_enough_free_secs(sbi, 0, 0)) {
>  		/*
>  		 * If there is no victim and no prefree segment but still not
>  		 * enough free sections, we should flush dent/node blocks and do
>  		 * garbage collections.
>  		 */
> -		if (__get_victim(sbi, &segno, gc_type) ||
> -						prefree_segments(sbi)) {
> -			write_checkpoint(sbi, &cpc);
> -			segno = NULL_SEGNO;
> -		} else if (has_not_enough_free_secs(sbi, 0, 0)) {
> -			write_checkpoint(sbi, &cpc);
> -		}
> +		gc_type = FG_GC;
> +		write_checkpoint(sbi, &cpc);
>  	}
>  
> -	if (segno == NULL_SEGNO && !__get_victim(sbi, &segno, gc_type))
> -		goto stop;
> +	if (!__get_victim(sbi, &segno, gc_type)) {
> +		if (sync)
> +			goto stop;
> +		else if (gc_type == FG_GC
> +				&& has_not_enough_free_secs(sbi, sec_freed, 0))
> +			goto gc_more;

Will we deadloop here?

Thanks,

> +		else
> +			goto stop;
> +	}
>  	ret = 0;
>  
>  	if (do_garbage_collect(sbi, segno, &gc_list, gc_type) &&
> 


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Re: [PATCH] f2fs: continue to do fg_gc even if beyond max_victim_search

[heyunlei]

On 2016/9/22 18:55, Chao Yu wrote:
> On 2016/9/22 11:48, Yunlei He wrote:
>> For forground gc, if can't find a victim in one max_victim_search,
>> try it again.
>>
>> Signed-off-by: Yunlei He <heyunlei@huawei.com>
>> ---
>>  fs/f2fs/gc.c | 23 ++++++++++++-----------
>>  1 file changed, 12 insertions(+), 11 deletions(-)
>>
>> diff --git a/fs/f2fs/gc.c b/fs/f2fs/gc.c
>> index 24acbbb..19e51a5 100644
>> --- a/fs/f2fs/gc.c
>> +++ b/fs/f2fs/gc.c
>> @@ -916,24 +916,25 @@ gc_more:
>>  		goto stop;
>>  	}
>>
>> -	if (gc_type == BG_GC && has_not_enough_free_secs(sbi, sec_freed, 0)) {
>> -		gc_type = FG_GC;
>> +	if (gc_type == BG_GC && has_not_enough_free_secs(sbi, 0, 0)) {
>>  		/*
>>  		 * If there is no victim and no prefree segment but still not
>>  		 * enough free sections, we should flush dent/node blocks and do
>>  		 * garbage collections.
>>  		 */
>> -		if (__get_victim(sbi, &segno, gc_type) ||
>> -						prefree_segments(sbi)) {
>> -			write_checkpoint(sbi, &cpc);
>> -			segno = NULL_SEGNO;
>> -		} else if (has_not_enough_free_secs(sbi, 0, 0)) {
>> -			write_checkpoint(sbi, &cpc);
>> -		}
>> +		gc_type = FG_GC;
>> +		write_checkpoint(sbi, &cpc);
>>  	}
>>
>> -	if (segno == NULL_SEGNO && !__get_victim(sbi, &segno, gc_type))
>> -		goto stop;
>> +	if (!__get_victim(sbi, &segno, gc_type)) {
>> +		if (sync)
>> +			goto stop;
>> +		else if (gc_type == FG_GC
>> +				&& has_not_enough_free_secs(sbi, sec_freed, 0))
>> +			goto gc_more;
>
> Will we deadloop here?
>
Does no victim(whole partition) and has_not_enough_free_secs both satisfied at the same time?

If stop FG_GC here, it will come again soon, besides, sec_freed will not change to free segments,

for no checkpoint update.

Thanks,

> Thanks,
>
>> +		else
>> +			goto stop;
>> +	}
>>  	ret = 0;
>>
>>  	if (do_garbage_collect(sbi, segno, &gc_list, gc_type) &&
>>
>
>
> .
>


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