Re: [PATCH] Change synchronize_rcu() in scsi_device_quiesce() into synchronize_sched()

Hello,

On Mon, Mar 19, 2018 at 04:18:54PM +0000, Bart Van Assche wrote:

The algorithm explained above does not depend on sched-rcu. But because percpu_ref_tryget_live() uses sched-rcu and because we need to add an RCU lock around that call we are forced to use sched-rcu. I hope this makes it clear.

This could be me being slow but can you explain how what percpu_ref_tryget_live() uses internally affects whether we can use regular RCU around it?

Thanks.