Re: [PATCH 3/9] blk-mq: Relocate shared sbitmap resize in blk_mq_update_nr_requests()

John Garry
2021-07-20T08:06:09Z

On 20/07/2021 08:50, Ming Lei wrote:
>> Signed-off-by: John Garry<john.garry@huawei.com>
>> ---
>> block/blk-mq.c | 13 ++++++++-----
>> 1 file changed, 8 insertions(+), 5 deletions(-)
>>
>> diff --git a/block/blk-mq.c b/block/blk-mq.c
>> index ae28f470893c..56e3c6fdba60 100644
>> --- a/block/blk-mq.c
>> +++ b/block/blk-mq.c
>> @@ -3624,8 +3624,6 @@ int blk_mq_update_nr_requests(struct request_queue *q, unsigned int nr)
>> if (!hctx->sched_tags) {
>> ret = blk_mq_tag_update_depth(hctx, &hctx->tags, nr,
>> false);
>> - if (!ret && blk_mq_is_sbitmap_shared(set->flags))
>> - blk_mq_tag_resize_shared_sbitmap(set, nr);
>> } else {
>> ret = blk_mq_tag_update_depth(hctx, &hctx->sched_tags,
>> nr, true);
>> @@ -3643,9 +3641,14 @@ int blk_mq_update_nr_requests(struct request_queue *q, unsigned int nr)
>> }
>> if (!ret) {
>> q->nr_requests = nr;
>> - if (q->elevator && blk_mq_is_sbitmap_shared(set->flags))
>> - sbitmap_queue_resize(&q->sched_bitmap_tags,
>> - nr - set->reserved_tags);
>> + if (blk_mq_is_sbitmap_shared(set->flags)) {

Hi Ming,

>> + if (q->elevator) {
>> + sbitmap_queue_resize(&q->sched_bitmap_tags,
>> + nr - set->reserved_tags);

I have learned that some people prefer {} for multi-line single
statements, like this.

Anyway, more code is added here later in the series, so better to add {}
now, rather than re-arrange code later.

>> + } else {
>> + blk_mq_tag_resize_shared_sbitmap(set, nr);
>> + }
> The above two {} can be removed.

Thanks,
John