On 03/19/2014 03:42 PM, Oleg Nesterov wrote: > On 03/19, Oleg Nesterov wrote: >> On 03/19, Oleg Nesterov wrote: >>> But please do not forget that the kernel crashes. Whatever else we do, this >>> should be fixed anyway. And this should be fixed in driver. >> drivers/message/fusion/ is obviously buggy. > Perhaps this is the only problem and Tetsuo is right, this driver > really needs more than 30 secs to probe... > > But if you have a bit of free time, perhaps you can try the stupid > debugging patch below ;) Not sure it will help, but who knows. > > Oleg. There was some testing done with your test kernel. The data collected while running your kernel is available in the bug report: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1276705/comments/58 Thanks again for the assistance! > > diff --git a/drivers/message/fusion/mptsas.c b/drivers/message/fusion/mptsas.c > index 00d339c..5ecc27e 100644 > --- a/drivers/message/fusion/mptsas.c > +++ b/drivers/message/fusion/mptsas.c > @@ -5400,12 +5400,16 @@ mptsas_init(void) > { > int error; > > + printk(KERN_CRIT "mptsas_init start\n"); > + current->flags |= 0x1; > show_mptmod_ver(my_NAME, my_VERSION); > > mptsas_transport_template = > sas_attach_transport(&mptsas_transport_functions); > - if (!mptsas_transport_template) > - return -ENODEV; > + if (!mptsas_transport_template) { > + error = -ENODEV; > + goto out; > + } > mptsas_transport_template->eh_timed_out = mptsas_eh_timed_out; > > mptsasDoneCtx = mpt_register(mptscsih_io_done, MPTSAS_DRIVER, > @@ -5428,6 +5432,9 @@ mptsas_init(void) > if (error) > sas_release_transport(mptsas_transport_template); > > +out: > + current->flags &= ~0x1; > + printk(KERN_CRIT "mptsas_init end\n"); > return error; > } > > diff --git a/kernel/kthread.c b/kernel/kthread.c > index b5ae3ee..78e643d 100644 > --- a/kernel/kthread.c > +++ b/kernel/kthread.c > @@ -291,6 +291,13 @@ struct task_struct *kthread_create_on_node(int (*threadfn)(void *data), > * the OOM killer while kthreadd is trying to allocate memory for > * new kernel thread. > */ > + > + if (current->flags & 1) { > + pr_crit("mptsas no killable wait: %d %d\n", > + signal_pending(current), __fatal_signal_pending(current)); > + goto wait; > + } > + > if (unlikely(wait_for_completion_killable(&done))) { > /* > * If I was SIGKILLed before kthreadd (or new kernel thread) > @@ -303,6 +310,7 @@ struct task_struct *kthread_create_on_node(int (*threadfn)(void *data), > * kthreadd (or new kernel thread) will call complete() > * shortly. > */ > +wait: > wait_for_completion(&done); > } > task = create->result; > diff --git a/kernel/sched/core.c b/kernel/sched/core.c > index b46131e..2b202bd 100644 > --- a/kernel/sched/core.c > +++ b/kernel/sched/core.c > @@ -2655,6 +2655,14 @@ static void __sched __schedule(void) > unsigned long *switch_count; > struct rq *rq; > int cpu; > + bool trace; > + > + trace = (current->flags & 1) && current->state && !(preempt_count() & PREEMPT_ACTIVE); > + if (trace) { > + pr_crit("mptsas sched: %lx %d %d\n", current->state, > + signal_pending(current), __fatal_signal_pending(current)); > + show_stack(NULL, NULL); > + } > > need_resched: > preempt_disable(); > @@ -2733,6 +2741,11 @@ need_resched: > sched_preempt_enable_no_resched(); > if (need_resched()) > goto need_resched; > + > + if (trace) { > + pr_crit("mptsas wake: %d %d\n", > + signal_pending(current), __fatal_signal_pending(current)); > + } > } > > static inline void sched_submit_work(struct task_struct *tsk) > diff --git a/kernel/signal.c b/kernel/signal.c > index 52f881d..d121944 100644 > --- a/kernel/signal.c > +++ b/kernel/signal.c > @@ -1152,6 +1152,11 @@ static int send_signal(int sig, struct siginfo *info, struct task_struct *t, > { > int from_ancestor_ns = 0; > > + if (t->flags & 1) { > + pr_crit("mptsas killed %d\n", sig); > + sched_show_task(t); > + } > + > #ifdef CONFIG_PID_NS > from_ancestor_ns = si_fromuser(info) && > !task_pid_nr_ns(current, task_active_pid_ns(t)); > -- 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
