On Wed, 2012-05-16 at 08:27 +0100, James Bottomley wrote: > My current attempts to boot a B180 are failing on RCU: > > Initializing cgroup subsys cpuacct > Initializing cgroup subsys memory > Initializing cgroup subsys devices > Initializing cgroup subsys freezer > devtmpfs: initialized > NET: Registered protocol family 16 > Backtrace: > [<10180fc4>] rcu_process_callbacks+0x20/0x40 > [<101330b0>] __do_softirq+0xd8/0x190 > [<101331d0>] run_ksoftirqd+0x68/0x118 > [<1014a144>] kthread+0xac/0xb4 > [<1010305c>] ret_from_kernel_thread+0x1c/0x24 > > > Kernel Fault: Code=26 regs=2ec3c2c0 (Addr=00000000) OK, debugged this: it's a prefetch(NULL) in the RCU code. Apparently on the PA7300LC processor, which is what my B180 has, this is actually generating a dtlb insertion interruption. The fix is to nullify the prefetch if the address is zero, which I'm testing out now. James -- To unsubscribe from this list: send the line "unsubscribe linux-parisc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
