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authorPeter Zijlstra <peterz@infradead.org>2016-03-18 16:28:04 +0100
committerSteven Rostedt <rostedt@goodmis.org>2016-03-22 18:04:10 -0400
commit7e6867bf831c71fe0e47438831ae3a94d4c7ab3c (patch)
treeaff6902663d850f314a23900a8caebf9a78e2a86 /kernel/trace/trace_output.c
parent3debb0a9ddb16526de8b456491b7db60114f7b5e (diff)
tracing: Record and show NMI state
The latency tracer format has a nice column to indicate IRQ state, but this is not able to tell us about NMI state. When tracing perf interrupt handlers (which often run in NMI context) it is very useful to see how the events nest. Link: http://lkml.kernel.org/r/20160318153022.105068893@infradead.org Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Diffstat (limited to 'kernel/trace/trace_output.c')
-rw-r--r--kernel/trace/trace_output.c10
1 files changed, 7 insertions, 3 deletions
diff --git a/kernel/trace/trace_output.c b/kernel/trace/trace_output.c
index 282982195e09..0bb9cf2d53e6 100644
--- a/kernel/trace/trace_output.c
+++ b/kernel/trace/trace_output.c
@@ -389,7 +389,9 @@ int trace_print_lat_fmt(struct trace_seq *s, struct trace_entry *entry)
char irqs_off;
int hardirq;
int softirq;
+ int nmi;
+ nmi = entry->flags & TRACE_FLAG_NMI;
hardirq = entry->flags & TRACE_FLAG_HARDIRQ;
softirq = entry->flags & TRACE_FLAG_SOFTIRQ;
@@ -415,10 +417,12 @@ int trace_print_lat_fmt(struct trace_seq *s, struct trace_entry *entry)
}
hardsoft_irq =
+ (nmi && hardirq) ? 'Z' :
+ nmi ? 'z' :
(hardirq && softirq) ? 'H' :
- hardirq ? 'h' :
- softirq ? 's' :
- '.';
+ hardirq ? 'h' :
+ softirq ? 's' :
+ '.' ;
trace_seq_printf(s, "%c%c%c",
irqs_off, need_resched, hardsoft_irq);