Huang, Ying wrote: >>From: Stefan Richter [mailto:[EMAIL PROTECTED] >> >>How can subsystems control multithreaded vs. singlethreaded probes? >> >>For example, the IEEE 1394 subsystem should probe different nodes in >>parallel, but different units on the same node serially. Similar >>requirements exist with other hardware. > > For subsystems specific dependency problems, a field as follow can be > added into struct device: > > struct device *depend; > > The parallel device probing code will not do probing for the device, > unless the device pointed by "depend" has been probed,
A bad API. Subsystems and the driver core will both traverse the trees (usually just lists) which can be built from the depend pointers, and the trees grow and shrink dynamically. Perhaps it would be simpler if the subsystem would just use a mutex per group of devices which have to be serialized. *However*, IMO parallelized probing should be implemented in the subsystems themselves in the first place, _not in the driver core_. The subsystems know where parallelism is possible and safe and effective, the driver core doesn't. -- Stefan Richter -=====-=-=== -==- -=--- http://arcgraph.de/sr/ - 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/
