 0c4df02d73
			
		
	
	
	0c4df02d73
	
	
	
		
			
			This patch has been invaluable in my adventures finding issues in the perf NMI handler. I'm as big a fan of printk() as anybody is, but using printk() in NMIs is deadly when they're happening frequently. Even hacking in trace_printk() ended up eating enough CPU to throw off some of the measurements I was making. Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: paulus@samba.org Cc: acme@ghostprotocols.net Cc: Dave Hansen <dave@sr71.net> Signed-off-by: Ingo Molnar <mingo@kernel.org>
		
			
				
	
	
		
			37 lines
		
	
	
	
		
			741 B
			
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			37 lines
		
	
	
	
		
			741 B
			
		
	
	
	
		
			C
		
	
	
	
	
	
| #undef TRACE_SYSTEM
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| #define TRACE_SYSTEM nmi
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| 
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| #if !defined(_TRACE_NMI_H) || defined(TRACE_HEADER_MULTI_READ)
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| #define _TRACE_NMI_H
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| 
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| #include <linux/ktime.h>
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| #include <linux/tracepoint.h>
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| 
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| TRACE_EVENT(nmi_handler,
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| 
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| 	TP_PROTO(void *handler, s64 delta_ns, int handled),
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| 
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| 	TP_ARGS(handler, delta_ns, handled),
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| 
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| 	TP_STRUCT__entry(
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| 		__field(	void *,		handler	)
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| 		__field(	s64,		delta_ns)
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| 		__field(	int,		handled	)
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| 	),
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| 
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| 	TP_fast_assign(
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| 		__entry->handler = handler;
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| 		__entry->delta_ns = delta_ns;
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| 		__entry->handled = handled;
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| 	),
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| 
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| 	TP_printk("%ps() delta_ns: %lld handled: %d",
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| 		__entry->handler,
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| 		__entry->delta_ns,
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| 		__entry->handled)
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| );
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| 
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| #endif /* _TRACE_NMI_H */
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| 
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| /* This part ust be outside protection */
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| #include <trace/define_trace.h>
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