On 2022/2/24 5:37 上午, Tejun Heo wrote:

Hello,

quoted

quoted

We just want to provide the flexibility for the user to open/close a policy
per device. If we need to the policy on a device, we needn't to waste cpu

sorry, it should be "If we don't need the policy on a device" ;)

Yeah, that's what modularization does but why does it need a separate user
interface for loading? Everything else inits on insmod and exits on rmmod
and autoloading has been delegated to udev a very long time ago. The
interface you added for loading module doesn't make sense to me.

The initial version of this patchset has two targets：
(1) Add a sysfs interface to open/close the policy per device. Then we needn't
    waste cpu cycles and memory if the device doesn't need the policy.
(2) Make the policies modular, then it easy to maintain the code of policy in
    production environment as we only need to close the policy and replace the
    .ko file.

The loading module when open policy in sysfs interface is just to avoid modprobe
manually. There is similar operation when switch io scheduler.

And as Christoph suggested, the modularization has been get rid of in next version.

Thanks
Jianchao