[dm-devel] [PATCH 13/15] dm-zoned: allocate zone by device index

[Hannes Reinecke]

On 5/28/20 6:08 AM, Damien Le Moal wrote:
> On Wed, 2020-05-27 at 08:22 +0200, Hannes Reinecke wrote:
>> When allocating a zone we should pass in an indicator on which
>> device the zone should be allocated; this increases performance
>> for a multi-device setup as then reclaim can allocate zones on
>> the device for which reclaim is running.
>>
>> Signed-off-by: Hannes Reinecke <hare at suse.de>
>> ---
>>   drivers/md/dm-zoned-metadata.c | 17 +++++++++++------
>>   drivers/md/dm-zoned-reclaim.c  |  3 ++-
>>   drivers/md/dm-zoned.h          |  3 ++-
>>   3 files changed, 15 insertions(+), 8 deletions(-)
>>
>> diff --git a/drivers/md/dm-zoned-metadata.c b/drivers/md/dm-zoned-metadata.c
>> index 689c1dd7ab20..0d65af94309a 100644
>> --- a/drivers/md/dm-zoned-metadata.c
>> +++ b/drivers/md/dm-zoned-metadata.c
>> @@ -2045,7 +2045,7 @@ struct dm_zone *dmz_get_chunk_mapping(struct dmz_metadata *zmd, unsigned int chu
>>   			goto out;
>>   
>>   		/* Allocate a random zone */
>> -		dzone = dmz_alloc_zone(zmd, alloc_flags);
>> +		dzone = dmz_alloc_zone(zmd, 0, alloc_flags);
>>   		if (!dzone) {
>>   			if (dmz_dev_is_dying(zmd)) {
>>   				dzone = ERR_PTR(-EIO);
>> @@ -2151,7 +2151,7 @@ struct dm_zone *dmz_get_chunk_buffer(struct dmz_metadata *zmd,
>>   		goto out;
>>   
>>   	/* Allocate a random zone */
>> -	bzone = dmz_alloc_zone(zmd, alloc_flags);
>> +	bzone = dmz_alloc_zone(zmd, 0, alloc_flags);
>>   	if (!bzone) {
>>   		if (dmz_dev_is_dying(zmd)) {
>>   			bzone = ERR_PTR(-EIO);
>> @@ -2182,11 +2182,12 @@ struct dm_zone *dmz_get_chunk_buffer(struct dmz_metadata *zmd,
>>    * Get an unmapped (free) zone.
>>    * This must be called with the mapping lock held.
>>    */
>> -struct dm_zone *dmz_alloc_zone(struct dmz_metadata *zmd, unsigned long flags)
>> +struct dm_zone *dmz_alloc_zone(struct dmz_metadata *zmd, unsigned int dev_idx,
>> +			       unsigned long flags)
>>   {
>>   	struct list_head *list;
>>   	struct dm_zone *zone;
>> -	unsigned int dev_idx = 0;
>> +	int i = 0;
>>   
>>   again:
>>   	if (flags & DMZ_ALLOC_CACHE)
>> @@ -2202,8 +2203,12 @@ struct dm_zone *dmz_alloc_zone(struct dmz_metadata *zmd, unsigned long flags)
>>   		 */
>>   		if (!(flags & DMZ_ALLOC_RECLAIM))
>>   			return NULL;
>> -		if (dev_idx < zmd->nr_devs) {
>> -			dev_idx++;
>> +		/*
>> +		 * Try to allocate from other devices
>> +		 */
>> +		if (i < zmd->nr_devs) {
>> +			dev_idx = (dev_idx + 1) % zmd->nr_devs;
> 
> Hu ? You deleted dev_idx declaration above...
> 
It's now the function argument ...

Cheers,

Hannes
-- 
Dr. Hannes Reinecke            Teamlead Storage & Networking
hare at suse.de                               +49 911 74053 688
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