On Tue, 20 May 2008 17:55:54 +0800 Dave Young <hidave.darkstar@xxxxxxxxx> wrote: > Converting class semaphore to mutex cause lockdep warnings due to > class_interface_register/unregister will possible call device_add/del Shouldn't we just fix that? > For the class_interface users here add a class_reclassify macro to > reclassify the lock class of their struct class. > > Signed-off-by: Dave Young <hidave.darkstar@xxxxxxxxx> > > --- > include/linux/device.h | 7 +++++++ > 1 file changed, 7 insertions(+) > > --- linux/include/linux/device.h 2008-05-19 12:29:54.000000000 +0800 > +++ linux.new/include/linux/device.h 2008-05-19 14:42:25.000000000 +0800 > @@ -529,4 +529,11 @@ extern const char *dev_driver_string(str > MODULE_ALIAS("char-major-" __stringify(major) "-" __stringify(minor)) > #define MODULE_ALIAS_CHARDEV_MAJOR(major) \ > MODULE_ALIAS("char-major-" __stringify(major) "-*") > + > +#define class_reclassify(class) \ > +do { \ > + static struct lock_class_key class_key; \ > + lockdep_set_class_and_name(&(class)->mutex, &class_key, \ > + (class)->name); \ > +} while (0) > #endif /* _DEVICE_H_ */ I think it would need a lavish comment explaining what it is for, and the reasons for its existence. Perhaps this should be a kernel-wide thing in lockdep.h. But then that would invite people to use it, and it looks like a bad thing. device.h does not include lockdep.h, so putting this here assumes that callees have already included lockdep.h. This is the sort of assumption which leads to compilation errors. -- To unsubscribe from this list: send the line "unsubscribe linux-scsi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html