[PATCH 27/41] perf session: Flag if the event stream is entirely in memory

From: Adrian Hunter
Date: Mon Jul 14 2014 - 06:12:43 EST


Flag if the event stream is a file that has been mmapped
in one go.

This is useful, for example, if a tool needs to keep an
event for later reference. If the new flag is set, a
pointer to the event can be retained, otherwise the
event must be copied.

Signed-off-by: Adrian Hunter <adrian.hunter@xxxxxxxxx>
---
tools/perf/util/session.c | 9 ++++++++-
tools/perf/util/session.h | 3 +++
2 files changed, 11 insertions(+), 1 deletion(-)

diff --git a/tools/perf/util/session.c b/tools/perf/util/session.c
index c1abe6b..7b0fb03 100644
--- a/tools/perf/util/session.c
+++ b/tools/perf/util/session.c
@@ -1319,8 +1319,10 @@ int __perf_session__process_events(struct perf_session *session,
ui_progress__init(&prog, file_size, "Processing events...");

mmap_size = MMAP_SIZE;
- if (mmap_size > file_size)
+ if (mmap_size > file_size) {
mmap_size = file_size;
+ session->one_mmap = true;
+ }

memset(mmaps, 0, sizeof(mmaps));

@@ -1342,6 +1344,10 @@ remap:
mmaps[map_idx] = buf;
map_idx = (map_idx + 1) & (ARRAY_SIZE(mmaps) - 1);
file_pos = file_offset + head;
+ if (session->one_mmap) {
+ session->one_mmap_addr = buf;
+ session->one_mmap_offset = file_offset;
+ }

more:
event = fetch_mmaped_event(session, head, mmap_size, buf);
@@ -1387,6 +1393,7 @@ out_err:
ui_progress__finish();
perf_session__warn_about_errors(session, tool);
perf_session_free_sample_buffers(session);
+ session->one_mmap = false;
return err;
}

diff --git a/tools/perf/util/session.h b/tools/perf/util/session.h
index 3140f8a..0321013 100644
--- a/tools/perf/util/session.h
+++ b/tools/perf/util/session.h
@@ -36,6 +36,9 @@ struct perf_session {
struct trace_event tevent;
struct events_stats stats;
bool repipe;
+ bool one_mmap;
+ void *one_mmap_addr;
+ u64 one_mmap_offset;
struct ordered_samples ordered_samples;
struct perf_data_file *file;
};
--
1.8.3.2

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