On Thu, Apr 23, 2015 at 02:02:29PM +0200, Paolo Bonzini wrote: > > > On 23/04/2015 13:51, Marcelo Tosatti wrote: > >>> > > https://bugzilla.redhat.com/show_bug.cgi?id=1174664 > >> > > >> > That was the missing volatile in an asm. Older compilers didn't catch > >> > it. :( > > How do you know that? It looks like memory corruption (look at the > > pattern at the end). > > I suspect some kind of operator error there, it makes no sense. if (unlikely(s->flags & SLAB_POISON)) memset(start, POISON_INUSE, PAGE_SIZE << order); * Padding is done using 0x5a (POISON_INUSE) > On the other hand, bug 1178975 is much clearer and the symptoms are the > same. In that bug, you can see that the same kernel source works on f20 > (package version 3.17.7-200.fc20.x86_64) and fails on f21 (package > version 3.17.7-300.fc21.x86_64). Of course the compiler is different. > The newer one hoists the lsl out of the loop; if you get a CPU migration > at the wrong time, the cpu != cpu1 condition will always be true the > loop will never exit. > > Paolo -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
