On Fri, 19 Sep 2014, Petr Mladek wrote: > The 3rd version of the patchset is slightly reordered and refactored > as suggested earlier. See below for more details. > > IMHO, the result is more clean. But feel free to ask me to revert it. > I do not want to make the review more complicated. Well, I double checked > the diff of patches files between v2 and v3. It is pretty small and only > the expected changes are there. > > Changes in: > + v3: > + split the optimization of hub->hdev reference counting > into separate patch; usable standalone (1st patch) > > + switch order of the two patches that convert the kthread > and that remove the while cycle in hub_event(); it is > cleaner (2nd and 3rd patch) > > + use ordered workqueue by default; it makes it compatible > with the original kthread solution (3rd patch) > > + added optional patch that allows to process events > in parallel (6th patch) > > + fixed the suggested stylistic problems (2nd and 3rd patch) > > > + v2: > + solved potential races: > + get hub->kref in kick_hub_wq() > + call usb_get_dev(hdev) in hub_probe() > and usb_put_dev(hdev) in hub_release() > + INIT_WORK only once in hub_probe() > > + do not call cancel_work_sync() in hub_disconnect() > to keep it fast > > + rename kick_khubd() to kick_hub_wq() already > in the first patch; IMHO, it is cleaner while > adding only very few changes > > > The workqueue API is well defined and tested. It has many options > that could be used to tune the scheduling. The code is usually > easier and thus more safe. It allows to avoid the extra thread > in most cases. It has has clearly defined behavior vrt. system suspend. > > This patchset converts khubd into the workqueue. It saves one thread, > lock, and list. > > It looks huge but the main change is in the first patch. The rest is > simple renaming of functions, comments and documentation. > > > Thanks a lot Alan Stern and Tejun Heo for hints and guidance. > > The patches can be applied either against Linus' tree or linux-next. Very nice work. I haven't tried it out, but it all looks good. No doubt we will be able to sort out unforeseen troubles if any arise, without much difficulty. For all six patches, Acked-by: Alan Stern <stern@xxxxxxxxxxxxxxxxxxx> Alan Stern -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
