On 9/7/22 7:08 AM, Bart Van Assche wrote:

On 8/28/22 21:00, Ming Lei wrote:

quoted

Firstly task_work_add() is used in several drivers. In ublk driver's
usage, request batching submission can only be applied with task_work_add,
and usually get better IOPS.

Secondly from this API's definition, the added work is always run in
the task context, and when task is exiting, either the work is rejected
to be added, or drained in do_exit(). In this way, not see obvious
disadvantage or potential issue by exporting it for module's usage.

So export it, then ublk driver can get simplified, meantime with better
performance.

If task_work_add() is exported, shouldn't task_work_cancel() be exported
too? Anyway:

Not if it isn't currently used...

On the patch itself, it definitely makes sense in the context of ublk.
My hesitation is mostly around not really wanting to export this to
generic modular users. It's OK for core interfaces, of which ublk is
on the way to becoming, but I really don't like the idea of random
modules using it. But that's not really something we can manage with
the export, it's either exported or it's not...

-- 
Jens Axboe