perf intel-pt: Improve PT documentation slightly

Document the higher level --insn-trace etc. perf script options.

Include the howto how to build xed into the manpage
Signed-off-by: Andi Kleen <ak@linux.intel.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Link: http://lore.kernel.org/lkml/20201014035346.4772-1-andi@firstfloor.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/Documentation/perf-intel-pt.txt

@@ -112,6 +112,32 @@ The flags are "bcrosyiABEx" which stand for branch, call, return, conditional,
 system, asynchronous, interrupt, transaction abort, trace begin, trace end, and
 in transaction, respectively.
 
+perf script also supports higher level ways to dump instruction traces:
+
+	perf script --insn-trace --xed
+
+Dump all instructions. This requires installing the xed tool (see XED below)
+Dumping all instructions in a long trace can be fairly slow. It is usually better
+to start with higher level decoding, like
+
+	perf script --call-trace
+
+or
+
+	perf script --call-ret-trace
+
+and then select a time range of interest. The time range can then be examined
+in detail with
+
+	perf script --time starttime,stoptime --insn-trace --xed
+
+While examining the trace it's also useful to filter on specific CPUs using
+the -C option
+
+	perf script --time starttime,stoptime --insn-trace --xed -C 1
+
+Dump all instructions in time range on CPU 1.
+
 Another interesting field that is not printed by default is 'ipc' which can be
 displayed as follows:
 
@@ -1110,6 +1136,10 @@ To display PEBS events from the Intel PT trace, use the itrace 'o' option e.g.
 
 	perf script --itrace=oe
 
+XED
+---
+
+include::build-xed.txt[]
 
 SEE ALSO
 --------