On Mon, Jul 04, 2022 at 07:19:09PM +0300, Sagi Grimberg wrote: > > > > > > > diff --git a/drivers/block/Kconfig b/drivers/block/Kconfig > > > > > > index fdb81f2794cd..d218089cdbec 100644 > > > > > > --- a/drivers/block/Kconfig > > > > > > +++ b/drivers/block/Kconfig > > > > > > @@ -408,6 +408,12 @@ config BLK_DEV_RBD > > > > > > If unsure, say N. > > > > > > +config BLK_DEV_UBLK > > > > > > + bool "Userspace block driver" > > > > > > > > > > Really? why compile this to the kernel and not tristate as loadable > > > > > module? > > > > So far, this is only one reason: task_work_add() is required, which > > > > isn't exported for modules. > > > > > > So why not exporting it? > > > Doesn't seem like a good justification to build it into the kernel. > > > > Sagi, > > > > If I understand correctly, the task_work_add function is quite a core > > API that we probably want to avoid exposing directly to (out-of-tree) > > modules? I agree, though, it would be great to have this buildable as a > > module for general use cases. Would it make sense to have it exposed > > through a thin built-in wrapper, specific to UBD, which is exported, and > > therefore able to invoke that function? Is it a reasonable approach? > > All I'm saying is that either we should expose it (or an interface to > it) if it has merit, or use something else (use a workqueue). There isn't replacement for task_work_add(). If module has to be supported, we can add one command for running the work function in the ubq context, that will add some cost. > Having a block driver driver builtin is probably not the answer. Not sure, there are at least two drivers which use the API. Thanks, Ming
