On Wed, Oct 5, 2016 at 12:16 PM, Bart Van Assche <bart.vanassche@xxxxxxxxxxx> wrote: > On 10/01/16 15:56, Ming Lei wrote: >> >> If we just call the rcu/srcu read lock(or the mutex) around .queue_rq(), >> the >> above code needn't to be duplicated any more. > > > Hello Ming, > > Can you have a look at the attached patch? That patch uses an srcu read lock > for all queue types, whether or not the BLK_MQ_F_BLOCKING flag has been set. That is much cleaner now. > Additionally, I have dropped the QUEUE_FLAG_QUIESCING flag. Just like > previous versions, this patch has been tested. I think the flag of QUEUE_FLAG_QUIESCING is still needed because we have to set this flag to prevent new coming .queue_rq() from being run, and synchronize_srcu() won't wait for completion of that at all (see section of 'Update-Side Primitives' in [1]). [1] https://lwn.net/Articles/202847/ -- Ming Lei -- To unsubscribe from this list: send the line "unsubscribe linux-block" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
