[tip:perf/core] perf session: Add reader object

[tip-bot for Jiri Olsa]

Commit-ID:  82715eb184c55b5097c8f1022f54303c2ddbc329
Gitweb:     https://git.kernel.org/tip/82715eb184c55b5097c8f1022f54303c2ddbc329
Author:     Jiri Olsa <jolsa@xxxxxxxxxx>
AuthorDate: Thu, 10 Jan 2019 11:12:58 +0100
Committer:  Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
CommitDate: Mon, 21 Jan 2019 15:15:57 -0300

perf session: Add reader object

Add a session private reader object to encapsulate the reading of the
event data block. Starting with a 'fd' field.

Signed-off-by: Jiri Olsa <jolsa@xxxxxxxxxx>
Acked-by: Namhyung Kim <namhyung@xxxxxxxxxx>
Cc: Alexander Shishkin <alexander.shishkin@xxxxxxxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Link: http://lkml.kernel.org/r/20190110101301.6196-4-jolsa@xxxxxxxxxx
Signed-off-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
---
 tools/perf/util/session.c | 10 ++++++++--
 1 file changed, 8 insertions(+), 2 deletions(-)

diff --git a/tools/perf/util/session.c b/tools/perf/util/session.c
index c8c2069fb01e..06379cc87f59 100644
--- a/tools/perf/util/session.c
+++ b/tools/perf/util/session.c
@@ -1820,11 +1820,17 @@ fetch_mmaped_event(struct perf_session *session,
 #define NUM_MMAPS 128
 #endif
 
+struct reader {
+	int	fd;
+};
+
 static int __perf_session__process_events(struct perf_session *session)
 {
+	struct reader rd = {
+		.fd		= perf_data__fd(session->data),
+	};
 	struct ordered_events *oe = &session->ordered_events;
 	struct perf_tool *tool = session->tool;
-	int fd = perf_data__fd(session->data);
 	u64 data_offset = session->header.data_offset;
 	u64 data_size = session->header.data_size;
 	u64 head, page_offset, file_offset, file_pos, size;
@@ -1864,7 +1870,7 @@ static int __perf_session__process_events(struct perf_session *session)
 		mmap_flags = MAP_PRIVATE;
 	}
 remap:
-	buf = mmap(NULL, mmap_size, mmap_prot, mmap_flags, fd,
+	buf = mmap(NULL, mmap_size, mmap_prot, mmap_flags, rd.fd,
 		   file_offset);
 	if (buf == MAP_FAILED) {
 		pr_err("failed to mmap file\n");