On Mon, Apr 06, 2015 at 09:22:51AM -0700, Dmitry Torokhov wrote: > On Tue, Mar 31, 2015 at 04:39:49PM -0400, Tejun Heo wrote: > > On Mon, Mar 30, 2015 at 04:20:02PM -0700, 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. > > > > > > Changes from v1: > > > > > > - Changed verbage in change logs and code to emphasise that > > > PROBE_PREFER_ASYNCHRONOUS is a temporary measure and the end goal is > > > to enable asynchronous probing by default, as requested by Tejun. > > > > Looks good to me. Please feel free to add > > > > Acked-by: Tejun Heo <[email protected]> > > Greg, it would be great if it could make it in 4.1.
It's on my list of patches to review next... -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
