On Mon, Sep 8, 2014 at 8:03 PM, Tejun Heo [off-list ref] wrote:

On Mon, Sep 08, 2014 at 07:57:28PM -0700, Luis R. Rodriguez wrote:

quoted

quoted

I think we
just should make exceptions sensible so that it works fine in practice
for now (and I don't think that'd be too hard).  So, the only
cooperation necessary from userland would be just saying "I don't
wanna wait for device probing on module load."

But we're talking about drivers that have a flag that says 'you gotta
wait sucker', what do we want systemd to do then? I'd be happy if it'd
would not send the sigkill for these drivers, for example.

Hah?  Can you give me an example?  I'm having hard time imagining a
driver with such requirement given our current driver core
implementation.

I didn't say I had one in mind, but if you're certain these *shouldn't
exist* that's sufficient by me as well.

OK so I'll respin this series to enable a sysctl that would enable
async probe for *all drivers* using queue_work(system_unbound_wq) and
only use sync probe for now on request_module() users, we'll address
scheduling issues as they come up. I'll be ignoring built-in.

On the systemd side of things it should enable this sysctl and for
older kernels what should it do?

 Luis