Re: [PATCH 2/2] f2fs:use fggc_set_cold_data instead of set_cold_data in fggc

[Hou Pengyang <houpengyang@huawei.com>]

On 2017/2/24 10:07, Chao Yu wrote:
> On 2017/2/23 10:04, Hou Pengyang wrote:
>> On 2017/2/23 8:39, Jaegeuk Kim wrote:
>>> Hi Pengyang,
Hi Chao,
>>>
>>> On 02/22, Hou Pengyang wrote:
>>>> When no dirty colde segment for fggc ssr, we do NOT set_cold_data.
>>>
>>> The get_ssr_segment() finds a victim segment across all the hot/warm/cold data
>>> logs. When does this happen?
>>>
>> Oh, I miss the travel across hot/warm/cold, sorry.
>> how about the following filter in get_victim_segment, which can avoid
>> unnecessary afterwards bitmap scanning.
>>
>> Thanks,
>>
>> diff --git a/fs/f2fs/gc.c b/fs/f2fs/gc.c
>> index a0eed23..00791d2 100644
>> --- a/fs/f2fs/gc.c
>> +++ b/fs/f2fs/gc.c
>> @@ -290,9 +290,16 @@ static int get_victim_by_default(struct
>> f2fs_sb_info *sbi,
>>           unsigned int secno, last_victim;
>>           unsigned int last_segment = MAIN_SEGS(sbi);
>>           unsigned int nsearched = 0;
>> +       int nr_dirty;
>>
>>           mutex_lock(&dirty_i->seglist_lock);
>>
>> +       if (alloc_mode == SSR) {
>> +               nr_dirty = dirty_i->nr_dirty[type];
>> +               if (!nr_dirty)
>
> Needs to clean up.
>
> if (!dirty_i->nr_dirty[type])

As Jaegeuk explained, p.max_search has skipped no # of victims scenario

	if (p.max_search == 0)
		goto out;
Thanks,
>
> Reviewed-by: Chao Yu <yuchao0@huawei.com>
>
> Thanks,
>
>> +                       goto out;
>> +       }
>> +
>>           p.alloc_mode = alloc_mode;
>>           select_policy(sbi, gc_type, type, &p);
>>
>>
>>> Thanks,
>>>
>>>>
>>>> Signed-off-by: Hou Pengyang <houpengyang@huawei.com>
>>>> ---
>>>>    fs/f2fs/gc.c | 21 ++++++++++++++++++++-
>>>>    1 file changed, 20 insertions(+), 1 deletion(-)
>>>>
>>>> diff --git a/fs/f2fs/gc.c b/fs/f2fs/gc.c
>>>> index 4ee749f..a0eed23 100644
>>>> --- a/fs/f2fs/gc.c
>>>> +++ b/fs/f2fs/gc.c
>>>> @@ -666,6 +666,25 @@ static void move_encrypted_block(struct inode *inode, block_t bidx,
>>>>    	f2fs_put_page(page, 1);
>>>>    }
>>>>
>>>> +/*
>>>> + * If NOT enough dirty cold data segments for fggc, fggc would consume
>>>> + * a valuable free segment, which would slow down the fggc procedure,
>>>> + * If there are NO COLD dirty segment, we do not set_cold_page.
>>>> + */
>>>> +static void fggc_set_cold_data(struct page *page)
>>>> +{
>>>> +	struct f2fs_sb_info *sbi = F2FS_P_SB(page);
>>>> +	struct dirty_seglist_info *dirty_i = DIRTY_I(sbi);
>>>> +	int nr_cold_dirties;
>>>> +
>>>> +	mutex_lock(&dirty_i->seglist_lock);
>>>> +	nr_cold_dirties = dirty_i->nr_dirty[DIRTY_COLD_DATA];
>>>> +	mutex_unlock(&dirty_i->seglist_lock);
>>>> +
>>>> +	if (nr_cold_dirties)
>>>> +		set_cold_data(page);
>>>> +
>>>> +}
>>>>    static void move_data_page(struct inode *inode, block_t bidx, int gc_type,
>>>>    							unsigned int segno, int off)
>>>>    {
>>>> @@ -706,7 +725,7 @@ static void move_data_page(struct inode *inode, block_t bidx, int gc_type,
>>>>    			remove_dirty_inode(inode);
>>>>    		}
>>>>
>>>> -		set_cold_data(page);
>>>> +		fggc_set_cold_data(page);
>>>>
>>>>    		err = do_write_data_page(&fio);
>>>>    		if (err == -ENOMEM && is_dirty) {
>>>> --
>>>> 2.10.1
>>>>
>>>>
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>>>
>>> .
>>>
>>
>>
>>
>> .
>>
>
>
> .
>



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