Re: [PATCH -next v3] block: remove init_mutex and open-code blk_iolatency_try_init

Hi, Jens

在 2023/08/11 22:12, Jens Axboe 写道:

On Thu, 10 Aug 2023 11:51:11 +0800, Li Lingfeng wrote:

quoted

Commit a13696b83da4 ("blk-iolatency: Make initialization lazy") adds
a mutex named "init_mutex" in blk_iolatency_try_init for the race
condition of initializing RQ_QOS_LATENCY.
Now a new lock has been add to struct request_queue by commit a13bd91be223
("block/rq_qos: protect rq_qos apis with a new lock"). And it has been
held in blkg_conf_open_bdev before calling blk_iolatency_init.
So it's not necessary to keep init_mutex in blk_iolatency_try_init, just
remove it.

[...]

Applied, thanks!

[1/1] block: remove init_mutex and open-code blk_iolatency_try_init
       commit: 4eb44d10766ac0fae5973998fd2a0103df1d3fe1

This version has a minor problem that pss in mutex for
lockdep_assert_held() is not a pointer:

 > lockdep_assert_held(ctx.bdev->bd_queue->rq_qos_mutex);

should be:
lockdep_assert_held(&ctx.bdev->bd_queue->rq_qos_mutex);

Perhaps can you drop this patch for now, and Lingfeng can send a v4?

Thanks,
Kuai

Best regards,