[PATCH] rcu: fix rcu stall detection in tiny implementation

[Miroslav Benes]

The current tiny RCU stall detection depends on presence of pending callbacks in
the list (*rcp->curtail et al.). But they are none even in case of real CPU
stalls prohibiting the detection. When the check for callback presence is
removed, INFO about the stall is correctly printed.

Signed-off-by: Miroslav Benes <mbenes@xxxxxxx>
---
 kernel/rcu/tiny_plugin.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/kernel/rcu/tiny_plugin.h b/kernel/rcu/tiny_plugin.h
index 858c565..3f743fa 100644
--- a/kernel/rcu/tiny_plugin.h
+++ b/kernel/rcu/tiny_plugin.h
@@ -145,7 +145,7 @@ static void check_cpu_stall(struct rcu_ctrlblk *rcp)
 	rcp->ticks_this_gp++;
 	j = jiffies;
 	js = ACCESS_ONCE(rcp->jiffies_stall);
-	if (*rcp->curtail && ULONG_CMP_GE(j, js)) {
+	if (ULONG_CMP_GE(j, js)) {
 		pr_err("INFO: %s stall on CPU (%lu ticks this GP) idle=%llx (t=%lu jiffies q=%ld)\n",
 		       rcp->name, rcp->ticks_this_gp, rcu_dynticks_nesting,
 		       jiffies - rcp->gp_start, rcp->qlen);
-- 
2.1.2

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