On 2019/03/11 6:31, yuyufen wrote:
> ping?
>
>
> On 2019/3/1 9:28, Yufen Yu wrote:
>> For q->poll_nsec == -1, means doing classic poll, not hybrid poll.
>> We introduce a new flag BLK_MQ_POLL_CLASSIC to replace -1, which
>> may make code much easier to read.
>>
>> Signed-off-by: Yufen Yu <[email protected]>
>> ---
>> 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..e70202e3b378 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_CLASSIC;
>>
>> 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_CLASSIC)
>> return false;
>>
>> if (!blk_qc_t_is_internal(cookie))
>> diff --git a/block/blk-sysfs.c b/block/blk-sysfs.c
>> index 590d1ef2f961..8639e135687e 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_CLASSIC)
>> 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)
Since val is an int obtained with kstrtoint(), val can be a negative value other
than -1. So what about something like:
if (val == BLK_MQ_POLL_CLASSIC)
q->poll_nsec = BLK_MQ_POLL_CLASSIC;
else if (val >= 0)
q->poll_nsec = val * 1000;
else
return -EINVAL;
That would avoid problems with negative values other than -1.
>> - q->poll_nsec = -1;
>> + q->poll_nsec = BLK_MQ_POLL_CLASSIC;
>> else
>> q->poll_nsec = val * 1000;
>>
>> diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
>> index 338604dff7d0..f9c2ebf5e621 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
>>
>> +/* Doing classic polling */
>> +#define BLK_MQ_POLL_CLASSIC -1
>> +
>> /*
>> * Maximum number of blkcg policies allowed to be registered concurrently.
>> * Defined here to simplify include dependency.
--
Damien Le Moal
Western Digital Research
