[PATCH v3 1/8] perf session: Move all state items to reader object

[Alexey Bayduraev]

We need all the state info about reader in separate object to load data
from multiple files, so we can keep multiple readers at the same time.
Moving all items that need to be kept from reader__process_events to
the reader object. Introducing mmap_cur to keep current mapping.

Suggested-by: Jiri Olsa <jolsa@xxxxxxxxxx>
Acked-by: Namhyung Kim <namhyung@xxxxxxxxx>
Reviewed-by: Riccardo Mancini <rickyman7@xxxxxxxxx>
Tested-by: Riccardo Mancini <rickyman7@xxxxxxxxx>
Signed-off-by: Alexey Bayduraev <alexey.v.bayduraev@xxxxxxxxxxxxxxx>
---
 tools/perf/util/session.c | 63 ++++++++++++++++++++++-----------------
 1 file changed, 35 insertions(+), 28 deletions(-)

diff --git a/tools/perf/util/session.c b/tools/perf/util/session.c
index 069c2cfdd3be..bf73e8c1f15c 100644
--- a/tools/perf/util/session.c
+++ b/tools/perf/util/session.c
@@ -2171,6 +2171,13 @@ struct reader {
 	u64		 data_offset;
 	reader_cb_t	 process;
 	bool		 in_place_update;
+	char		 *mmaps[NUM_MMAPS];
+	size_t		 mmap_size;
+	int		 mmap_idx;
+	char		 *mmap_cur;
+	u64		 file_pos;
+	u64		 file_offset;
+	u64		 head;
 };
 
 static int
@@ -2178,28 +2185,27 @@ reader__process_events(struct reader *rd, struct perf_session *session,
 		       struct ui_progress *prog)
 {
 	u64 data_size = rd->data_size;
-	u64 head, page_offset, file_offset, file_pos, size;
-	int err = 0, mmap_prot, mmap_flags, map_idx = 0;
-	size_t	mmap_size;
-	char *buf, *mmaps[NUM_MMAPS];
+	u64 page_offset, size;
+	int err = 0, mmap_prot, mmap_flags;
+	char *buf, **mmaps = rd->mmaps;
 	union perf_event *event;
 	s64 skip;
 
 	page_offset = page_size * (rd->data_offset / page_size);
-	file_offset = page_offset;
-	head = rd->data_offset - page_offset;
+	rd->file_offset = page_offset;
+	rd->head = rd->data_offset - page_offset;
 
 	ui_progress__init_size(prog, data_size, "Processing events...");
 
 	data_size += rd->data_offset;
 
-	mmap_size = MMAP_SIZE;
-	if (mmap_size > data_size) {
-		mmap_size = data_size;
+	rd->mmap_size = MMAP_SIZE;
+	if (rd->mmap_size > data_size) {
+		rd->mmap_size = data_size;
 		session->one_mmap = true;
 	}
 
-	memset(mmaps, 0, sizeof(mmaps));
+	memset(mmaps, 0, sizeof(rd->mmaps));
 
 	mmap_prot  = PROT_READ;
 	mmap_flags = MAP_SHARED;
@@ -2211,35 +2217,36 @@ reader__process_events(struct reader *rd, struct perf_session *session,
 		mmap_flags = MAP_PRIVATE;
 	}
 remap:
-	buf = mmap(NULL, mmap_size, mmap_prot, mmap_flags, rd->fd,
-		   file_offset);
+	buf = mmap(NULL, rd->mmap_size, mmap_prot, mmap_flags, rd->fd,
+		   rd->file_offset);
 	if (buf == MAP_FAILED) {
 		pr_err("failed to mmap file\n");
 		err = -errno;
 		goto out;
 	}
-	mmaps[map_idx] = buf;
-	map_idx = (map_idx + 1) & (ARRAY_SIZE(mmaps) - 1);
-	file_pos = file_offset + head;
+	mmaps[rd->mmap_idx] = rd->mmap_cur = buf;
+	rd->mmap_idx = (rd->mmap_idx + 1) & (ARRAY_SIZE(rd->mmaps) - 1);
+	rd->file_pos = rd->file_offset + rd->head;
 	if (session->one_mmap) {
 		session->one_mmap_addr = buf;
-		session->one_mmap_offset = file_offset;
+		session->one_mmap_offset = rd->file_offset;
 	}
 
 more:
-	event = fetch_mmaped_event(head, mmap_size, buf, session->header.needs_swap);
+	event = fetch_mmaped_event(rd->head, rd->mmap_size, rd->mmap_cur,
+				   session->header.needs_swap);
 	if (IS_ERR(event))
 		return PTR_ERR(event);
 
 	if (!event) {
-		if (mmaps[map_idx]) {
-			munmap(mmaps[map_idx], mmap_size);
-			mmaps[map_idx] = NULL;
+		if (mmaps[rd->mmap_idx]) {
+			munmap(mmaps[rd->mmap_idx], rd->mmap_size);
+			mmaps[rd->mmap_idx] = NULL;
 		}
 
-		page_offset = page_size * (head / page_size);
-		file_offset += page_offset;
-		head -= page_offset;
+		page_offset = page_size * (rd->head / page_size);
+		rd->file_offset += page_offset;
+		rd->head -= page_offset;
 		goto remap;
 	}
 
@@ -2248,9 +2255,9 @@ reader__process_events(struct reader *rd, struct perf_session *session,
 	skip = -EINVAL;
 
 	if (size < sizeof(struct perf_event_header) ||
-	    (skip = rd->process(session, event, file_pos)) < 0) {
+	    (skip = rd->process(session, event, rd->file_pos)) < 0) {
 		pr_err("%#" PRIx64 " [%#x]: failed to process type: %d [%s]\n",
-		       file_offset + head, event->header.size,
+		       rd->file_offset + rd->head, event->header.size,
 		       event->header.type, strerror(-skip));
 		err = skip;
 		goto out;
@@ -2259,8 +2266,8 @@ reader__process_events(struct reader *rd, struct perf_session *session,
 	if (skip)
 		size += skip;
 
-	head += size;
-	file_pos += size;
+	rd->head += size;
+	rd->file_pos += size;
 
 	err = __perf_session__process_decomp_events(session);
 	if (err)
@@ -2271,7 +2278,7 @@ reader__process_events(struct reader *rd, struct perf_session *session,
 	if (session_done())
 		goto out;
 
-	if (file_pos < data_size)
+	if (rd->file_pos < data_size)
 		goto more;
 
 out:
-- 
2.19.0