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authorPaul E. McKenney <paulmck@linux.vnet.ibm.com>2010-08-10 14:28:53 -0700
committerPaul E. McKenney <paulmck@linux.vnet.ibm.com>2010-08-20 09:00:12 -0700
commit53d84e004d5e8c018be395c4330dc72fd60bd13e (patch)
tree6d5b265442ac42c7cc73147b0de0d029644e312b /kernel/rcutree.c
parent8cdd32a918350430483751feaae1c19cef816f69 (diff)
downloadop-kernel-dev-53d84e004d5e8c018be395c4330dc72fd60bd13e.zip
op-kernel-dev-53d84e004d5e8c018be395c4330dc72fd60bd13e.tar.gz
rcu: permit suppressing current grace period's CPU stall warnings
When using a kernel debugger, a long sojourn in the debugger can get you lots of RCU CPU stall warnings once you resume. This might not be helpful, especially if you are using the system console. This patch therefore allows RCU CPU stall warnings to be suppressed, but only for the duration of the current set of grace periods. This differs from Jason's original patch in that it adds support for tiny RCU and preemptible RCU, and uses a slightly different method for suppressing the RCU CPU stall warning messages. Signed-off-by: Jason Wessel <jason.wessel@windriver.com> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Tested-by: Jason Wessel <jason.wessel@windriver.com>
Diffstat (limited to 'kernel/rcutree.c')
-rw-r--r--kernel/rcutree.c20
1 files changed, 20 insertions, 0 deletions
diff --git a/kernel/rcutree.c b/kernel/rcutree.c
index ff21411..42140a8 100644
--- a/kernel/rcutree.c
+++ b/kernel/rcutree.c
@@ -565,6 +565,22 @@ static int rcu_panic(struct notifier_block *this, unsigned long ev, void *ptr)
return NOTIFY_DONE;
}
+/**
+ * rcu_cpu_stall_reset - prevent further stall warnings in current grace period
+ *
+ * Set the stall-warning timeout way off into the future, thus preventing
+ * any RCU CPU stall-warning messages from appearing in the current set of
+ * RCU grace periods.
+ *
+ * The caller must disable hard irqs.
+ */
+void rcu_cpu_stall_reset(void)
+{
+ rcu_sched_state.jiffies_stall = jiffies + ULONG_MAX / 2;
+ rcu_bh_state.jiffies_stall = jiffies + ULONG_MAX / 2;
+ rcu_preempt_stall_reset();
+}
+
static struct notifier_block rcu_panic_block = {
.notifier_call = rcu_panic,
};
@@ -584,6 +600,10 @@ static void check_cpu_stall(struct rcu_state *rsp, struct rcu_data *rdp)
{
}
+void rcu_cpu_stall_reset(void)
+{
+}
+
static void __init check_cpu_stall_init(void)
{
}
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