The printk()s in RCU stall warnings do not get flushed to the console
on ARM. Add the oops_in_progress flag back into the special trylock case in
console_trylock_for_printk(), and set the flag using "bust_spinlocks(1)".
This allows the printk() output to be flushed to the console.
Signed-off-by: Frank Rowand <frank.row...@am.sony.com>
---
kernel/printk.c | 5 3 + 2 - 0 !
kernel/rcutree.c | 14 14 + 0 - 0 !
2 files changed, 17 insertions(+), 2 deletions(-)
Index: b/kernel/printk.c
===================================================================
--- a/kernel/printk.c
+++ b/kernel/printk.c
@@ -1390,8 +1390,9 @@ static int console_trylock_for_printk(un
{
int retval = 0, wake = 0;
#ifdef CONFIG_PREEMPT_RT_FULL
- int lock = !early_boot_irqs_disabled && !irqs_disabled_flags(flags) &&
- (preempt_count() <= 1);
+ int lock = oops_in_progress || (
+ !early_boot_irqs_disabled && !irqs_disabled_flags(flags) &&
+ (preempt_count() <= 1));
#else
int lock = 1;
#endif
Index: b/kernel/rcutree.c
===================================================================
--- a/kernel/rcutree.c
+++ b/kernel/rcutree.c
@@ -758,6 +758,11 @@ static void print_other_cpu_stall(struct
raw_spin_unlock_irqrestore(&rnp->lock, flags);
/*
+ * Allow printk() to flush to device
+ */
+ bust_spinlocks(1);
+
+ /*
* OK, time to rat on our buddy...
* See Documentation/RCU/stallwarn.txt for info on how to debug
* RCU CPU stall warnings.
@@ -799,6 +804,8 @@ static void print_other_cpu_stall(struct
rcu_print_detail_task_stall(rsp);
+ bust_spinlocks(0);
+
force_quiescent_state(rsp, 0); /* Kick them all. */
}
@@ -808,6 +815,11 @@ static void print_cpu_stall(struct rcu_s
struct rcu_node *rnp = rcu_get_root(rsp);
/*
+ * Allow printk() to flush to device
+ */
+ bust_spinlocks(1);
+
+ /*
* OK, time to rat on ourselves...
* See Documentation/RCU/stallwarn.txt for info on how to debug
* RCU CPU stall warnings.
@@ -820,6 +832,8 @@ static void print_cpu_stall(struct rcu_s
if (!trigger_all_cpu_backtrace())
dump_stack();
+ bust_spinlocks(0);
+
raw_spin_lock_irqsave(&rnp->lock, flags);
if (ULONG_CMP_GE(jiffies, rsp->jiffies_stall))
rsp->jiffies_stall = jiffies +
--
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