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author | Sangmoon Kim <sangmoon.kim@samsung.com> | 2021-03-02 20:55:15 +0900 |
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committer | Paul E. McKenney <paulmck@kernel.org> | 2021-03-15 13:53:24 -0700 |
commit | 565cfb9e64dac1aadf7e2130fcda19a1c018df66 (patch) | |
tree | 07a85851e876c0cb1b270e51f6677c5fa9e44180 /kernel/rcu/tree_exp.h | |
parent | 7e937220afa3eada0d4611b31e4e3c60770e39b4 (diff) |
rcu/tree: Add a trace event for RCU CPU stall warnings
This commit adds a trace event which allows tracing the beginnings of RCU
CPU stall warnings on systems where sysctl_panic_on_rcu_stall is disabled.
The first parameter is the name of RCU flavor like other trace events.
The second parameter indicates whether this is a stall of an expedited
grace period, a self-detected stall of a normal grace period, or a stall
of a normal grace period detected by some CPU other than the one that
is stalled.
RCU CPU stall warnings are often caused by external-to-RCU issues,
for example, in interrupt handling or task scheduling. Therefore,
this event uses TRACE_EVENT, not TRACE_EVENT_RCU, to avoid requiring
those interested in tracing RCU CPU stalls to rebuild their kernels
with CONFIG_RCU_TRACE=y.
Reviewed-by: Uladzislau Rezki (Sony) <urezki@gmail.com>
Reviewed-by: Neeraj Upadhyay <neeraju@codeaurora.org>
Signed-off-by: Sangmoon Kim <sangmoon.kim@samsung.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Diffstat (limited to 'kernel/rcu/tree_exp.h')
-rw-r--r-- | kernel/rcu/tree_exp.h | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/kernel/rcu/tree_exp.h b/kernel/rcu/tree_exp.h index 6c6ff06d4ae6..2796084ef85a 100644 --- a/kernel/rcu/tree_exp.h +++ b/kernel/rcu/tree_exp.h @@ -521,6 +521,7 @@ static void synchronize_rcu_expedited_wait(void) if (rcu_stall_is_suppressed()) continue; panic_on_rcu_stall(); + trace_rcu_stall_warning(rcu_state.name, TPS("ExpeditedStall")); pr_err("INFO: %s detected expedited stalls on CPUs/tasks: {", rcu_state.name); ndetected = 0; |