Why was this change necessary? Can't you just add MarshalText ?

Why was this change necessary?

It can avoid type conversion like time.Duration(cfg.ScheduleDelay).

Can't you just add MarshalText ?

UnmarshalText is not added by me.
Isn't it used when loading config file? I will verify it.

@dnephin We need UnmarshalText when loading config file, otherwise containerd service can not start with the error log:

containerd: toml: type mismatch for scheduler.duration: expected table but found string

But I modify UnmarshalText like:

func (d duration) UnmarshalText(_ []byte) error {
	return nil
}

Still works well, don't know why! 😅

return nil is probably ignoring the problem, it suspect it will serialize to nothing.

My comment wasn't about UnarmshalText. I think it was correct and doesn't need to change.

I was suggesting it would be better to leave the type as type duration time.Duration and remove the other changes from this PR. I don't think the type conversion is a problem. The only thing that needs to change is adding MarshalText

@dnephin Thanks for review, have address your comment.