diff options
Diffstat (limited to 'kernel/rcu/tree_stall.h')
| -rw-r--r-- | kernel/rcu/tree_stall.h | 62 |
1 files changed, 37 insertions, 25 deletions
diff --git a/kernel/rcu/tree_stall.h b/kernel/rcu/tree_stall.h index 5e2fa6fd97f1..0c5d8516516a 100644 --- a/kernel/rcu/tree_stall.h +++ b/kernel/rcu/tree_stall.h @@ -347,26 +347,6 @@ static void rcu_dump_cpu_stacks(void) } } -#ifdef CONFIG_RCU_FAST_NO_HZ - -static void print_cpu_stall_fast_no_hz(char *cp, int cpu) -{ - struct rcu_data *rdp = per_cpu_ptr(&rcu_data, cpu); - - sprintf(cp, "last_accelerate: %04lx/%04lx dyntick_enabled: %d", - rdp->last_accelerate & 0xffff, jiffies & 0xffff, - !!rdp->tick_nohz_enabled_snap); -} - -#else /* #ifdef CONFIG_RCU_FAST_NO_HZ */ - -static void print_cpu_stall_fast_no_hz(char *cp, int cpu) -{ - *cp = '\0'; -} - -#endif /* #else #ifdef CONFIG_RCU_FAST_NO_HZ */ - static const char * const gp_state_names[] = { [RCU_GP_IDLE] = "RCU_GP_IDLE", [RCU_GP_WAIT_GPS] = "RCU_GP_WAIT_GPS", @@ -399,6 +379,15 @@ static bool rcu_is_gp_kthread_starving(unsigned long *jp) return j > 2 * HZ; } +static bool rcu_is_rcuc_kthread_starving(struct rcu_data *rdp, unsigned long *jp) +{ + unsigned long j = jiffies - READ_ONCE(rdp->rcuc_activity); + + if (jp) + *jp = j; + return j > 2 * HZ; +} + /* * Print out diagnostic information for the specified stalled CPU. * @@ -408,13 +397,12 @@ static bool rcu_is_gp_kthread_starving(unsigned long *jp) * of RCU grace periods that this CPU is ignorant of, for example, "1" * if the CPU was aware of the previous grace period. * - * Also print out idle and (if CONFIG_RCU_FAST_NO_HZ) idle-entry info. + * Also print out idle info. */ static void print_cpu_stall_info(int cpu) { unsigned long delta; bool falsepositive; - char fast_no_hz[72]; struct rcu_data *rdp = per_cpu_ptr(&rcu_data, cpu); char *ticks_title; unsigned long ticks_value; @@ -432,11 +420,10 @@ static void print_cpu_stall_info(int cpu) ticks_title = "ticks this GP"; ticks_value = rdp->ticks_this_gp; } - print_cpu_stall_fast_no_hz(fast_no_hz, cpu); delta = rcu_seq_ctr(rdp->mynode->gp_seq - rdp->rcu_iw_gp_seq); falsepositive = rcu_is_gp_kthread_starving(NULL) && rcu_dynticks_in_eqs(rcu_dynticks_snap(rdp)); - pr_err("\t%d-%c%c%c%c: (%lu %s) idle=%03x/%ld/%#lx softirq=%u/%u fqs=%ld %s%s\n", + pr_err("\t%d-%c%c%c%c: (%lu %s) idle=%03x/%ld/%#lx softirq=%u/%u fqs=%ld %s\n", cpu, "O."[!!cpu_online(cpu)], "o."[!!(rdp->grpmask & rdp->mynode->qsmaskinit)], @@ -449,10 +436,32 @@ static void print_cpu_stall_info(int cpu) rdp->dynticks_nesting, rdp->dynticks_nmi_nesting, rdp->softirq_snap, kstat_softirqs_cpu(RCU_SOFTIRQ, cpu), data_race(rcu_state.n_force_qs) - rcu_state.n_force_qs_gpstart, - fast_no_hz, falsepositive ? " (false positive?)" : ""); } +static void rcuc_kthread_dump(struct rcu_data *rdp) +{ + int cpu; + unsigned long j; + struct task_struct *rcuc; + + rcuc = rdp->rcu_cpu_kthread_task; + if (!rcuc) + return; + + cpu = task_cpu(rcuc); + if (cpu_is_offline(cpu) || idle_cpu(cpu)) + return; + + if (!rcu_is_rcuc_kthread_starving(rdp, &j)) + return; + + pr_err("%s kthread starved for %ld jiffies\n", rcuc->comm, j); + sched_show_task(rcuc); + if (!trigger_single_cpu_backtrace(cpu)) + dump_cpu_task(cpu); +} + /* Complain about starvation of grace-period kthread. */ static void rcu_check_gp_kthread_starvation(void) { @@ -624,6 +633,9 @@ static void print_cpu_stall(unsigned long gps) rcu_check_gp_kthread_expired_fqs_timer(); rcu_check_gp_kthread_starvation(); + if (!use_softirq) + rcuc_kthread_dump(rdp); + rcu_dump_cpu_stacks(); raw_spin_lock_irqsave_rcu_node(rnp, flags); |