On Tue, May 27, 2008 at 2:59 PM, Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> wrote: > On Tue, 27 May 2008 14:42:51 +0800 "Dave Young" <hidave.darkstar@xxxxxxxxx> wrote: > >> On Wed, May 21, 2008 at 1:21 AM, Greg KH <greg@xxxxxxxxx> wrote: >> > On Tue, May 20, 2008 at 03:02:32AM -0700, Andrew Morton wrote: >> >> 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? >> > >> > Um, no, that's a "feature" that some types of hardware and interfaces >> > require. >> > >> > This is one reason I really don't like this type of conversion, it's >> > causing lots of problems for no known gain. >> > >> > So I would just recommend dropping this patch set, the current "convert >> > class semaphore to a mutex" patch in the -mm tree is already causing >> > lockdep warnings, and trying to do something like this isn't really >> > going to solve the root problem here. >> >> At last, I decide to give up. >> >> Andrew, I could not do more for this issue now, you can drop the >> conversion patch if there's no suitable fix from others. >> > > If that semaphore is being used as a mutex then we should convert it to > a mutex (dammit). > > Leaving it implemented as a semphore is not the proper way of > suppressing the lockdep warnings. It would be better to convert it to > a mutex then add suitable (and suitably commented) open-coded lockdep > annotations to suppress the runtime warnings. I agree. > > And afaik that's pretty much what your patch did, except you added that > unpopular macro. If instead of the macro we were to convert that patch > to add open-coded lockdep annotation, what problems remain? > > Actually I want a best fix which could be accepted by all of you, and by me. It's not so easy. I can give another try without the macro. Thanks. --- Regards dave -- 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
