On Sun, Feb 08, 2015 at 08:59:41AM +0800, Greg KH wrote: > On Sun, Feb 08, 2015 at 01:47:29PM +1300, Michael Cree wrote: > > On Sat, Feb 07, 2015 at 10:30:44PM +0000, Mathieu Desnoyers wrote: > > > > On Fri, Feb 06, 2015 at 09:08:21PM -0500, Mathieu Desnoyers wrote: > > > > > A lockless_dereference() appears to be missing in llist_del_first(). > > > > > It should only matter for Alpha in practice. > > > > What could one anticipate to be the symptoms of such a missing > > lockless_dereference()? > > > > The Alpha kernel is behaving pretty well provided one builds a machine > > specific kernel and UP. When running an SMP kernel some packages > > (most notably the java runtime, but there are a few others) occasionally > > lock up in a pthread call --- could be a problem in libc rather then the > > kernel. > > Hm, if only UP alpha needs to be supported, odds are we could rip a lot > of odd stuff out of the kernel that deals with memory barriers and other > nasty locking things that the Alpha requires. > > Would that be ok? Or is someone somewhere going to want to be running a > SMP kernel on Alpha in the future? I am running an SMP kernel on a 3-cpu Alpha system; it mostly works just fine. I was just noting that there is something up with java---it locks up occassionally in a pthread call, and there are a few other packages that occasionally fail in test suites when being built under an SMP kernel but always pass when built under an UP kernel which suggests there is a little buglet somewhere in the SMP code, either in the kernel or in libc. Running an SMP system for the Debian Alpha build daemon at debian-ports is really useful for keeping up with the other architectures. Cheers Michael. -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html