Re: [PATCH v2 3/4] block: rename IOPRIO_BE_NR

[Damien Le Moal <Damien.LeMoal@wdc.com>]

On 2021/08/06 15:38, Hannes Reinecke wrote:
> On 8/6/21 7:11 AM, Damien Le Moal wrote:
>> The BFQ scheduler and ioprio_check_cap() both assume that the RT
>> priority class (IOPRIO_CLASS_RT) can have up to 8 different priority
>> levels. This is controlled using the macro IOPRIO_BE_NR, which is badly
>> named as the number of levels applies to the RT class.
>>
>> Rename IOPRIO_BE_NR to the class independent IOPRIO_NR_LEVELS to make
>> things clear.
>>
>> Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com>
>> ---
>>   block/bfq-iosched.c         | 8 ++++----
>>   block/bfq-iosched.h         | 4 ++--
>>   block/bfq-wf2q.c            | 6 +++---
>>   block/ioprio.c              | 3 +--
>>   fs/f2fs/sysfs.c             | 2 +-
>>   include/uapi/linux/ioprio.h | 4 ++--
>>   6 files changed, 13 insertions(+), 14 deletions(-)
>>
>> diff --git a/block/bfq-iosched.c b/block/bfq-iosched.c
>> index 1f38d75524ae..d5824cab34d7 100644
>> --- a/block/bfq-iosched.c
>> +++ b/block/bfq-iosched.c
>> @@ -2505,7 +2505,7 @@ void bfq_end_wr_async_queues(struct bfq_data *bfqd,
>>   	int i, j;
>>   
>>   	for (i = 0; i < 2; i++)
>> -		for (j = 0; j < IOPRIO_BE_NR; j++)
>> +		for (j = 0; j < IOPRIO_NR_LEVELS; j++)
>>   			if (bfqg->async_bfqq[i][j])
>>   				bfq_bfqq_end_wr(bfqg->async_bfqq[i][j]);
>>   	if (bfqg->async_idle_bfqq)
>> @@ -5290,10 +5290,10 @@ bfq_set_next_ioprio_data(struct bfq_queue *bfqq, struct bfq_io_cq *bic)
>>   		break;
>>   	}
>>   
>> -	if (bfqq->new_ioprio >= IOPRIO_BE_NR) {
>> +	if (bfqq->new_ioprio >= IOPRIO_NR_LEVELS) {
>>   		pr_crit("bfq_set_next_ioprio_data: new_ioprio %d\n",
>>   			bfqq->new_ioprio);
>> -		bfqq->new_ioprio = IOPRIO_BE_NR - 1;
>> +		bfqq->new_ioprio = IOPRIO_NR_LEVELS - 1;
>>   	}
>>   
>>   	bfqq->entity.new_weight = bfq_ioprio_to_weight(bfqq->new_ioprio);
>> @@ -6822,7 +6822,7 @@ void bfq_put_async_queues(struct bfq_data *bfqd, struct bfq_group *bfqg)
>>   	int i, j;
>>   
>>   	for (i = 0; i < 2; i++)
>> -		for (j = 0; j < IOPRIO_BE_NR; j++)
>> +		for (j = 0; j < IOPRIO_NR_LEVELS; j++)
>>   			__bfq_put_async_bfqq(bfqd, &bfqg->async_bfqq[i][j]);
>>   
>>   	__bfq_put_async_bfqq(bfqd, &bfqg->async_idle_bfqq);
>> diff --git a/block/bfq-iosched.h b/block/bfq-iosched.h
>> index 99c2a3cb081e..385e28a843d1 100644
>> --- a/block/bfq-iosched.h
>> +++ b/block/bfq-iosched.h
>> @@ -931,7 +931,7 @@ struct bfq_group {
>>   
>>   	void *bfqd;
>>   
>> -	struct bfq_queue *async_bfqq[2][IOPRIO_BE_NR];
>> +	struct bfq_queue *async_bfqq[2][IOPRIO_NR_LEVELS];
>>   	struct bfq_queue *async_idle_bfqq;
>>   
>>   	struct bfq_entity *my_entity;
>> @@ -948,7 +948,7 @@ struct bfq_group {
>>   	struct bfq_entity entity;
>>   	struct bfq_sched_data sched_data;
>>   
>> -	struct bfq_queue *async_bfqq[2][IOPRIO_BE_NR];
>> +	struct bfq_queue *async_bfqq[2][IOPRIO_NR_LEVELS];
>>   	struct bfq_queue *async_idle_bfqq;
>>   
>>   	struct rb_root rq_pos_tree;
>> diff --git a/block/bfq-wf2q.c b/block/bfq-wf2q.c
>> index 7a462df71f68..b74cc0da118e 100644
>> --- a/block/bfq-wf2q.c
>> +++ b/block/bfq-wf2q.c
>> @@ -505,7 +505,7 @@ static void bfq_active_insert(struct bfq_service_tree *st,
>>    */
>>   unsigned short bfq_ioprio_to_weight(int ioprio)
>>   {
>> -	return (IOPRIO_BE_NR - ioprio) * BFQ_WEIGHT_CONVERSION_COEFF;
>> +	return (IOPRIO_NR_LEVELS - ioprio) * BFQ_WEIGHT_CONVERSION_COEFF;
>>   }
>>   
>>   /**
>> @@ -514,12 +514,12 @@ unsigned short bfq_ioprio_to_weight(int ioprio)
>>    *
>>    * To preserve as much as possible the old only-ioprio user interface,
>>    * 0 is used as an escape ioprio value for weights (numerically) equal or
>> - * larger than IOPRIO_BE_NR * BFQ_WEIGHT_CONVERSION_COEFF.
>> + * larger than IOPRIO_NR_LEVELS * BFQ_WEIGHT_CONVERSION_COEFF.
>>    */
>>   static unsigned short bfq_weight_to_ioprio(int weight)
>>   {
>>   	return max_t(int, 0,
>> -		     IOPRIO_BE_NR * BFQ_WEIGHT_CONVERSION_COEFF - weight);
>> +		     IOPRIO_NR_LEVELS * BFQ_WEIGHT_CONVERSION_COEFF - weight);
>>   }
>>   
>>   static void bfq_get_entity(struct bfq_entity *entity)
>> diff --git a/block/ioprio.c b/block/ioprio.c
>> index bee628f9f1b2..ca6b136c5586 100644
>> --- a/block/ioprio.c
>> +++ b/block/ioprio.c
>> @@ -74,9 +74,8 @@ int ioprio_check_cap(int ioprio)
>>   			fallthrough;
>>   			/* rt has prio field too */
>>   		case IOPRIO_CLASS_BE:
>> -			if (data >= IOPRIO_BE_NR || data < 0)
>> +			if (data >= IOPRIO_NR_LEVELS || data < 0)
>>   				return -EINVAL;
>> -
>>   			break;
>>   		case IOPRIO_CLASS_IDLE:
>>   			break;
>> diff --git a/fs/f2fs/sysfs.c b/fs/f2fs/sysfs.c
>> index 6642246206bd..daad532a4e2b 100644
>> --- a/fs/f2fs/sysfs.c
>> +++ b/fs/f2fs/sysfs.c
>> @@ -378,7 +378,7 @@ static ssize_t __sbi_store(struct f2fs_attr *a,
>>   		ret = kstrtol(name, 10, &data);
>>   		if (ret)
>>   			return ret;
>> -		if (data >= IOPRIO_BE_NR || data < 0)
>> +		if (data >= IOPRIO_NR_LEVELS || data < 0)
>>   			return -EINVAL;
>>   
>>   		cprc->ckpt_thread_ioprio = IOPRIO_PRIO_VALUE(class, data);
>> diff --git a/include/uapi/linux/ioprio.h b/include/uapi/linux/ioprio.h
>> index abc40965aa96..b9d48744dacb 100644
>> --- a/include/uapi/linux/ioprio.h
>> +++ b/include/uapi/linux/ioprio.h
>> @@ -31,9 +31,9 @@ enum {
>>   };
>>   
>>   /*
>> - * 8 best effort priority levels are supported
>> + * The RT an BE priority classes support up to 8 priority levels.
> 
> This sentence no verb :-)

Hu ? "support" is a verb (to support). It is a noun too, but here, I use the verb :)

There is a typo though: s/an/and

"The RT and BE priority classes support up to 8 priority levels."

Arg... Sending v3 :)

> (maybe 'The RT class is an BE priority ...'?)
> 
> Cheers,
> 
> Hannes
> 


-- 
Damien Le Moal
Western Digital Research