Re: [PATCH 0/8] Asynchronous device/driver probing support

[Dmitry Torokhov <dmitry.torokhov@gmail.com>]

On Tue, Mar 03, 2015 at 01:18:52PM -0800, Dmitry Torokhov wrote:
> On Sat, Feb 07, 2015 at 06:06:15PM +0800, Greg Kroah-Hartman wrote:
> > On Tue, Feb 03, 2015 at 03:12:19PM -0800, Dmitry Torokhov wrote:
> > > On Fri, Jan 16, 2015 at 03:33:09PM -0800, Dmitry Torokhov wrote:
> > > > This series is a combination of changes proposed by Luis a couple months
> > > > ago and implementation used by Chrome OS. The issue we are trying to solve
> > > > here is "slow" devices and drivers spending "too much time" in their probe()
> > > > methods and it affects:
> > > > 
> > > > - overall kernel boot process when drivers are compiled into the kernel
> > > >   and slow devices stall entire boot progress;
> > > > - systemd desire to time out module loading process.
> > > > 
> > > > Unlike Luis' proposal we do make use of asycn_schedule() infrastructure
> > > > instead of using a dedicated workqueue, so all  existing synchronization
> > > > points in kernel that wait for device registration still work the same.
> > > > Also, the asynchronous probing is done not only during driver registration
> > > > (i.e. when devices are probed asynchronously only if they are registered
> > > > before the driver), but also during device registration and deferred probe
> > > > handling. This way slow devices do not stall kernel boot even when drivers
> > > > are compiled into the kernel.
> > > > 
> > > > The last patch is for adventurous people to try and force
> > > > fully-asynchronous boot. It works for me with limited success - I can boot
> > > > Rockhip-based box to userspace as long as I force serial to be sychronously
> > > > probed and ignore the fact that most devices are using "dummy" regulators
> > > > as regulator subsystem really expects regulators to be registered in
> > > > orderly fashion on OF-based systems.
> > > > 
> > > > Thanks,
> > > > Dmitry
> > > > 
> > > > 
> > > > Dmitry Torokhov (3):
> > > >   driver-core: add asynchronous probing support for drivers
> > > >   driver-core: platform_driver_probe() must probe synchronously
> > > >   module: add core_param_unsafe
> > > > 
> > > > Luis R. Rodriguez (5):
> > > >   module: add extra argument for parse_params() callback
> > > >   driver-core: add driver module asynchronous probe support
> > > >   driver-core: enable drivers to opt-out of async probe
> > > >   amd64_edac: enforce synchronous probe
> > > >   driver-core: allow forcing async probing for modules and builtins
> > > > 
> > > >  Documentation/kernel-parameters.txt |  13 +++
> > > >  arch/powerpc/mm/hugetlbpage.c       |   4 +-
> > > >  drivers/base/base.h                 |   1 +
> > > >  drivers/base/bus.c                  |  31 +++++--
> > > >  drivers/base/dd.c                   | 166 +++++++++++++++++++++++++++++++-----
> > > >  drivers/base/platform.c             |  13 +++
> > > >  drivers/edac/amd64_edac.c           |   1 +
> > > >  include/linux/device.h              |  26 ++++++
> > > >  include/linux/module.h              |   2 +
> > > >  include/linux/moduleparam.h         |  12 ++-
> > > >  init/main.c                         |  25 +++---
> > > >  kernel/module.c                     |  25 +++++-
> > > >  kernel/params.c                     |  11 ++-
> > > >  lib/dynamic_debug.c                 |   4 +-
> > > >  14 files changed, 284 insertions(+), 50 deletions(-)
> > > > 
> > > > -- 
> > > > 2.2.0.rc0.207.ga3a616c
> > > > 
> > > 
> > > *ping*
> > 
> > Sorry, I was waiting for someone else here to speak up.
> > 
> > It's too late for 3.20, I'll look at this when 3.20-rc1 is out, thanks,
> 
> Greg, please take another look.

Greg, since nobody seems to object can it be merged?

Thanks.

-- 
Dmitry