perf session: Define 'bytes_transferred' and 'bytes_compressed' metrics

Define 'bytes_transferred' and 'bytes_compressed' metrics to calculate
ratio in the end of the data collection:

	compression ratio = bytes_transferred / bytes_compressed

The 'bytes_transferred' metric accumulates the amount of bytes that was
extracted from the mmaped kernel buffers for compression, while
'bytes_compressed' accumulates the amount of bytes that was received
after applying compression.

Signed-off-by: Alexey Budankov <alexey.budankov@linux.intel.com>
Reviewed-by: Jiri Olsa <jolsa@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1d4bf499-cb03-26dc-6fc6-f14fec7622ce@linux.intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
diff --git a/tools/perf/util/env.h b/tools/perf/util/env.h
index 4f8e2b4..34868ca 100644
--- a/tools/perf/util/env.h
+++ b/tools/perf/util/env.h
@@ -62,6 +62,7 @@ struct perf_env {
 	struct cpu_topology_map	*cpu;
 	struct cpu_cache_level	*caches;
 	int			 caches_cnt;
+	u32			comp_ratio;
 	struct numa_node	*numa_nodes;
 	struct memory_node	*memory_nodes;
 	unsigned long long	 memory_bsize;
diff --git a/tools/perf/util/session.h b/tools/perf/util/session.h
index d96eccd..0e14884 100644
--- a/tools/perf/util/session.h
+++ b/tools/perf/util/session.h
@@ -35,6 +35,8 @@ struct perf_session {
 	struct ordered_events	ordered_events;
 	struct perf_data	*data;
 	struct perf_tool	*tool;
+	u64			bytes_transferred;
+	u64			bytes_compressed;
 };
 
 struct perf_tool;