perf record: Add new -I option to sample interrupted machine state

Add -I/--intr-regs option to capture machine state registers at
interrupt.

Add the corresponding man page description

Signed-off-by: Stephane Eranian <eranian@google.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1411559322-16548-6-git-send-email-eranian@google.com
Cc: cebbert.lkml@gmail.com
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Anshuman Khandual <khandual@linux.vnet.ibm.com>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Masanari Iida <standby24x7@gmail.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>

2 files changed, 8 insertions, 0 deletions

diff --git a/tools/perf/Documentation/perf-record.txt b/tools/perf/Documentation/perf-record.txt
index 398f8d53bd6d..af9a54ece024 100644
--- a/tools/perf/Documentation/perf-record.txt
+++ b/tools/perf/Documentation/perf-record.txt
@@ -214,6 +214,12 @@ if combined with -a or -C options.
 After starting the program, wait msecs before measuring. This is useful to
 filter out the startup phase of the program, which is often very different.
 
+-I::
+--intr-regs::
+Capture machine state (registers) at interrupt, i.e., on counter overflows for
+each sample. List of captured registers depends on the architecture. This option
+is off by default.
+
 SEE ALSO
 --------
 linkperf:perf-stat[1], linkperf:perf-list[1]
diff --git a/tools/perf/builtin-record.c b/tools/perf/builtin-record.c
index 582c4da155ea..8648c6d3003d 100644
--- a/tools/perf/builtin-record.c
+++ b/tools/perf/builtin-record.c
@@ -811,6 +811,8 @@ struct option __record_options[] = {
                     "sample transaction flags (special events only)"),
         OPT_BOOLEAN(0, "per-thread", &record.opts.target.per_thread,
                     "use per-thread mmaps"),
+        OPT_BOOLEAN('I', "intr-regs", &record.opts.sample_intr_regs,
+                    "Sample machine registers on interrupt"),
         OPT_END()
 };