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authorFrederic Weisbecker <fweisbec@gmail.com>2009-04-19 23:38:12 +0200
committerFrederic Weisbecker <fweisbec@gmail.com>2009-04-19 23:38:12 +0200
commite057a5e5647a1c9d0d0054fbd298bfa04b3d1cb4 (patch)
tree4495ffacfb31ff535c9e6fde5ea03f62dd3c3b53
parent8e668b5b3455207e4540fc7ccab9ecf70142f288 (diff)
tracing/core: Add current context on tracing recursion warning
In case of tracing recursion detection, we only get the stacktrace. But the current context may be very useful to debug the issue. This patch adds the softirq/hardirq/nmi context with the warning using lockdep context display to have a familiar output. v2: Use printk_once() v3: drop {hardirq,softirq}_context which depend on lockdep, only keep what is part of current->trace_recursion, sufficient to debug the warning source. [ Impact: print context necessary to debug recursion ] Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
-rw-r--r--kernel/trace/ring_buffer.c7
1 files changed, 7 insertions, 0 deletions
diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c
index b421b0ea9112..bffde630c4e2 100644
--- a/kernel/trace/ring_buffer.c
+++ b/kernel/trace/ring_buffer.c
@@ -1495,6 +1495,13 @@ static int trace_recursive_lock(void)
if (unlikely(current->trace_recursion & (1 << level))) {
/* Disable all tracing before we do anything else */
tracing_off_permanent();
+
+ printk_once(KERN_WARNING "Tracing recursion: "
+ "HC[%lu]:SC[%lu]:NMI[%lu]\n",
+ hardirq_count() >> HARDIRQ_SHIFT,
+ softirq_count() >> SOFTIRQ_SHIFT,
+ in_nmi());
+
WARN_ON_ONCE(1);
return -1;
}