From: Christian Borntraeger <borntraeger@xxxxxxxxxx> With lockdep we got the following trace after a panic: Badness at /home/autobuild/BUILD/linux-2.6.28-20090204/kernel/lockdep.c:2878 [...] Call Trace: [<0000000000176334>] lock_acquire+0x54/0xbc [<000000000050b4fe>] __atomic_notifier_call_chain+0x6e/0xdc [<000000000050b59c>] atomic_notifier_call_chain+0x30/0x44 [<0000000000504274>] panic+0xd0/0x1e8 [...] INFO: lockdep is turned off. Last Breaking-Event-Address: [<0000000000170e62>] check_flags+0xae/0x15c possible reason: unannotated irqs-off. lockdep is right. We missed a trace_hardirq_off in our smp_send_stop function and smp_send_stop is called before the panic call chain. Reported-by: Mijo <Safradin mijo@xxxxxxxxxxxxxxxxxx> Signed-off-by: Christian Borntraeger <borntraeger@xxxxxxxxxx> Signed-off-by: Martin Schwidefsky <schwidefsky@xxxxxxxxxx> --- arch/s390/kernel/smp.c | 2 ++ 1 file changed, 2 insertions(+) Index: quilt-2.6/arch/s390/kernel/smp.c =================================================================== --- quilt-2.6.orig/arch/s390/kernel/smp.c +++ quilt-2.6/arch/s390/kernel/smp.c @@ -32,6 +32,7 @@ #include <linux/delay.h> #include <linux/cache.h> #include <linux/interrupt.h> +#include <linux/irqflags.h> #include <linux/cpu.h> #include <linux/timex.h> #include <linux/bootmem.h> @@ -75,6 +76,7 @@ void smp_send_stop(void) /* Disable all interrupts/machine checks */ __load_psw_mask(psw_kernel_bits & ~PSW_MASK_MCHECK); + trace_hardirqs_off(); /* stop all processors */ for_each_online_cpu(cpu) { -- blue skies, Martin. "Reality continues to ruin my life." - Calvin. -- To unsubscribe from this list: send the line "unsubscribe linux-s390" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html