Re: [Patch v3 2/4] mm/migrate.c: wrap do_move_pages_to_node() and store_status()

[Wei Yang <richardw.yang@linux.intel.com>]

On Mon, Jan 27, 2020 at 10:36:42AM +0100, Michal Hocko wrote:
>On Sun 26-01-20 18:26:21, Wei Yang wrote:
>> Usually do_move_pages_to_node() and store_status() is a pair. There are
>> three places call this pair of functions with almost the same form.
>> 
>> This patch just wrap it to make it friendly to audience and also
>> consolidate the move and store action into one place.
>> 
>> Signed-off-by: Wei Yang <richardw.yang@linux.intel.com>
>
>I believe I have already acked this one. Anyway
>Acked-by: Michal Hocko <mhocko@suse.com>
>

Yep, since some change from original code, I dropped your ack.

Thanks

>> ---
>>  mm/migrate.c | 61 ++++++++++++++++++++++++++--------------------------
>>  1 file changed, 30 insertions(+), 31 deletions(-)
>> 
>> diff --git a/mm/migrate.c b/mm/migrate.c
>> index ae3db45c6a42..e816c8990296 100644
>> --- a/mm/migrate.c
>> +++ b/mm/migrate.c
>> @@ -1583,6 +1583,29 @@ static int add_page_for_migration(struct mm_struct *mm, unsigned long addr,
>>  	return err;
>>  }
>>  
>> +static int move_pages_and_store_status(struct mm_struct *mm, int node,
>> +		struct list_head *pagelist, int __user *status,
>> +		unsigned long nr_pages, int start, int i)
>> +{
>> +	int err;
>> +
>> +	err = do_move_pages_to_node(mm, pagelist, node);
>> +	if (err) {
>> +		/*
>> +		 * Positive err means the number of failed
>> +		 * pages to migrate.  Since we are going to
>> +		 * abort and return the number of non-migrated
>> +		 * pages, so need incude the rest of the
>> +		 * nr_pages that have not attempted as well.
>> +		 */
>> +		if (err > 0)
>> +			err += nr_pages - i - 1;
>> +		return err;
>> +	}
>> +	err = store_status(status, start, node, i - start);
>> +	return err;
>> +}
>> +
>>  /*
>>   * Migrate an array of page address onto an array of nodes and fill
>>   * the corresponding array of status.
>> @@ -1626,20 +1649,9 @@ static int do_pages_move(struct mm_struct *mm, nodemask_t task_nodes,
>>  			current_node = node;
>>  			start = i;
>>  		} else if (node != current_node) {
>> -			err = do_move_pages_to_node(mm, &pagelist, current_node);
>> -			if (err) {
>> -				/*
>> -				 * Positive err means the number of failed
>> -				 * pages to migrate.  Since we are going to
>> -				 * abort and return the number of non-migrated
>> -				 * pages, so need incude the rest of the
>> -				 * nr_pages that have not attempted as well.
>> -				 */
>> -				if (err > 0)
>> -					err += nr_pages - i - 1;
>> -				goto out;
>> -			}
>> -			err = store_status(status, start, current_node, i - start);
>> +			err = move_pages_and_store_status(mm, current_node,
>> +					&pagelist, status, nr_pages,
>> +					start, i);
>>  			if (err)
>>  				goto out;
>>  			start = i;
>> @@ -1668,13 +1680,8 @@ static int do_pages_move(struct mm_struct *mm, nodemask_t task_nodes,
>>  		if (err)
>>  			goto out_flush;
>>  
>> -		err = do_move_pages_to_node(mm, &pagelist, current_node);
>> -		if (err) {
>> -			if (err > 0)
>> -				err += nr_pages - i - 1;
>> -			goto out;
>> -		}
>> -		err = store_status(status, start, current_node, i - start);
>> +		err = move_pages_and_store_status(mm, current_node, &pagelist,
>> +				status, nr_pages, start, i);
>>  		if (err)
>>  			goto out;
>>  		current_node = NUMA_NO_NODE;
>> @@ -1684,16 +1691,8 @@ static int do_pages_move(struct mm_struct *mm, nodemask_t task_nodes,
>>  		return err;
>>  
>>  	/* Make sure we do not overwrite the existing error */
>> -	err1 = do_move_pages_to_node(mm, &pagelist, current_node);
>> -	/*
>> -	 * Don't have to report non-attempted pages here since:
>> -	 *     - If the above loop is done gracefully there is not non-attempted
>> -	 *       page.
>> -	 *     - If the above loop is aborted to it means more fatal error
>> -	 *       happened, should return err.
>> -	 */
>> -	if (!err1)
>> -		err1 = store_status(status, start, current_node, i - start);
>> +	err1 = move_pages_and_store_status(mm, current_node, &pagelist,
>> +			status, nr_pages, start, i);
>>  	if (err >= 0)
>>  		err = err1;
>>  out:
>> -- 
>> 2.17.1
>
>-- 
>Michal Hocko
>SUSE Labs

-- 
Wei Yang
Help you, Help me