Andi Kleen 7f47d8cc03 x86, tracing, perf: Add trace point for MSR accesses ... For debugging low level code interacting with the CPU it is often useful to trace the MSR read/writes. This gives a concise summary of PMU and other operations. perf has an ad-hoc way to do this using trace_printk, but it's somewhat limited (and also now spews ugly boot messages when enabled) Instead define real trace points for all MSR accesses. This adds three new trace points: read_msr and write_msr and rdpmc. They also report if the access faulted (if *_safe is used) This allows filtering and triggering on specific MSR values, which allows various more advanced debugging techniques. All the values are well defined in the CPU documentation. The trace can be post processed with Documentation/trace/postprocess/decode_msr.py to add symbolic MSR names to the trace. I only added it to native MSR accesses in C, not paravirtualized or in entry*.S (which is not too interesting) Originally the patch kit moved the MSRs out of line. This uses an alternative approach recommended by Steven Rostedt of only moving the trace calls out of line, but open coding the access to the jump label. Signed-off-by: Andi Kleen <ak@linux.intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Steven Rostedt <rostedt@goodmis.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephane Eranian <eranian@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vince Weaver <vincent.weaver@maine.edu> Link: http://lkml.kernel.org/r/1449018060-1742-3-git-send-email-andi@firstfloor.org Signed-off-by: Ingo Molnar <mingo@kernel.org>		2015-12-06 12:56:10 +01:00
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postprocess	x86, tracing, perf: Add trace point for MSR accesses	2015-12-06 12:56:10 +01:00
coresight.txt
events-kmem.txt
events-msr.txt	x86, tracing, perf: Add trace point for MSR accesses	2015-12-06 12:56:10 +01:00
events-nmi.txt
events-power.txt
events.txt	tracing: Add some documentation about set_event_pid	2015-11-03 16:37:15 -05:00
ftrace-design.txt
ftrace.txt	tracing: Add some documentation about set_event_pid	2015-11-03 16:37:15 -05:00
function-graph-fold.vim
intel_th.txt	intel_th: Add driver infrastructure for Intel(R) Trace Hub devices	2015-10-04 20:28:58 +01:00
kprobetrace.txt
mmiotrace.txt
ring-buffer-design.txt
stm.txt
tracepoint-analysis.txt
tracepoints.txt
uprobetracer.txt