On 2019/02/27 5:38, yuyufen wrote:
>
> On 2019/2/27 18:27, Marcos Paulo de Souza wrote:
>> Hello Yufen,
>>
>> On 2/27/19 3:21 AM, Yufen Yu wrote:
>>> For q->poll_nsec == -1, means using classic poll, not hybrid poll.
>>> We introduce a new flag BLK_POLL_DELAY_INVALID to replace -1, which
>>> may make code much easier to read.
>>
>> In the commit message you say BLK_POLL_DELAY_INVALID, but the code and
>> the commit title use BLK_MQ_POLL_HYBRID_INVALID. Is this a typo?
>>
>
> Thanks a lot for pointing out this fault. What I want to
> say is BLK_MQ_POLL_HYBRID_INVALID, not BLK_POLL_DELAY_INVALID.
>
> Yufen
> Thanks
>
>> Thanks.
>>
>>>
>>> Signed-off-by: Yufen Yu <yuyufen@xxxxxxxxxx>
>>> ---
>>> block/blk-mq.c | 4 ++--
>>> block/blk-sysfs.c | 4 ++--
>>> include/linux/blkdev.h | 3 +++
>>> 3 files changed, 7 insertions(+), 4 deletions(-)
>>>
>>> diff --git a/block/blk-mq.c b/block/blk-mq.c
>>> index 9437a5eb07cf..8df9f6e97d2e 100644
>>> --- a/block/blk-mq.c
>>> +++ b/block/blk-mq.c
>>> @@ -2857,7 +2857,7 @@ struct request_queue
>>> *blk_mq_init_allocated_queue(struct blk_mq_tag_set *set,
>>> /*
>>> * Default to classic polling
>>> */
>>> - q->poll_nsec = -1;
>>> + q->poll_nsec = BLK_MQ_POLL_HYBRID_INVALID;
>>> blk_mq_init_cpu_queues(q, set->nr_hw_queues);
>>> blk_mq_add_queue_tag_set(set, q);
>>> @@ -3389,7 +3389,7 @@ static bool blk_mq_poll_hybrid(struct
>>> request_queue *q,
>>> {
>>> struct request *rq;
>>> - if (q->poll_nsec == -1)
>>> + if (q->poll_nsec == BLK_MQ_POLL_HYBRID_INVALID)
>>> return false;
>>> if (!blk_qc_t_is_internal(cookie))
>>> diff --git a/block/blk-sysfs.c b/block/blk-sysfs.c
>>> index 590d1ef2f961..8775b898f96d 100644
>>> --- a/block/blk-sysfs.c
>>> +++ b/block/blk-sysfs.c
>>> @@ -360,7 +360,7 @@ static ssize_t queue_poll_delay_show(struct
>>> request_queue *q, char *page)
>>> {
>>> int val;
>>> - if (q->poll_nsec == -1)
>>> + if (q->poll_nsec == BLK_MQ_POLL_HYBRID_INVALID)
>>> val = -1;
>>> else
>>> val = q->poll_nsec / 1000;
>>> @@ -381,7 +381,7 @@ static ssize_t queue_poll_delay_store(struct
>>> request_queue *q, const char *page,
>>> return err;
>>> if (val == -1)
>>> - q->poll_nsec = -1;
>>> + q->poll_nsec = BLK_MQ_POLL_HYBRID_INVALID;
>>> else
>>> q->poll_nsec = val * 1000;
>>> diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
>>> index 338604dff7d0..2102447b67d9 100644
>>> --- a/include/linux/blkdev.h
>>> +++ b/include/linux/blkdev.h
>>> @@ -50,6 +50,9 @@ struct blk_stat_callback;
>>> /* Must be consistent with blk_mq_poll_stats_bkt() */
>>> #define BLK_MQ_POLL_STATS_BKTS 16
>>> +/* Using default classic polling */
>>> +#define BLK_MQ_POLL_HYBRID_INVALID -1
May be simply renaming this as BLK_MQ_POLL_CLASSIC would be even simpler ?
That matches the comment and also the actual use of the macro, i.e.:
if (q->poll_nsec == -1)
means "do classic polling", which would nicely fits with:
if (q->poll_nsec == BLK_MQ_POLL_CLASSIC)
A lot easier to understand in my opinion. Using BLK_MQ_POLL_HYBRID_INVALID as a
name is confusing with potential error cases where we actually want to do hybrid
polling but the poll sleep time is invalid.
>>> +
>>> /*
>>> * Maximum number of blkcg policies allowed to be registered
>>> concurrently.
>>> * Defined here to simplify include dependency.
>>>
>>
>> .
>>
>
>
>
--
Damien Le Moal
Western Digital Research
