Commit-ID: e057a5e5647a1c9d0d0054fbd298bfa04b3d1cb4
Gitweb: http://git.kernel.org/tip/e057a5e5647a1c9d0d0054fbd298bfa04b3d1cb4
Author: Frederic Weisbecker <fweisbec@xxxxxxxxx>
AuthorDate: Sun, 19 Apr 2009 23:38:12 +0200
Committer: Frederic Weisbecker <fweisbec@xxxxxxxxx>
CommitDate: Sun, 19 Apr 2009 23:38:12 +0200
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@xxxxxxxxx>
---
kernel/trace/ring_buffer.c | 7 +++++++
1 files changed, 7 insertions(+), 0 deletions(-)
diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c
index b421b0e..bffde63 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;
}
--
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