[PATCH v1 2/8] perf session: Document struct and constify auxtrace
From: Ian Rogers
Date: Thu Aug 29 2024 - 11:03:10 EST
perf_session is a central data structure to the tool so let's comment
it. The auxtrace callbacks are never modified in session so constify.
Signed-off-by: Ian Rogers <irogers@xxxxxxxxxx>
---
tools/perf/util/session.h | 48 ++++++++++++++++++++++++++++++++++++++-
1 file changed, 47 insertions(+), 1 deletion(-)
diff --git a/tools/perf/util/session.h b/tools/perf/util/session.h
index 7c8dd6956330..e56518639711 100644
--- a/tools/perf/util/session.h
+++ b/tools/perf/util/session.h
@@ -26,26 +26,72 @@ struct decomp_data {
struct zstd_data *zstd_decomp;
};
+/**
+ * struct perf_session- A Perf session holds the main state when the program is
+ * working with live perf events or reading data from an input file.
+ *
+ * The rough organization of a perf_session is:
+ * ```
+ * +--------------+ +-----------+ +------------+
+ * | Session |1..* ----->| Machine |1..* ----->| Thread |
+ * +--------------+ +-----------+ +------------+
+ * ```
+ */
struct perf_session {
+ /**
+ * @header: The read version of a perf_file_header, or captures global
+ * information from a live session.
+ */
struct perf_header header;
+ /** @machines: Machines within the session a host and 0 or more guests. */
struct machines machines;
+ /** @evlist: List of evsels/events of the session. */
struct evlist *evlist;
- struct auxtrace *auxtrace;
+ /** @auxtrace: callbacks to allow AUX area data decoding. */
+ const struct auxtrace *auxtrace;
+ /** @itrace_synth_opts: AUX area tracing synthesis options. */
struct itrace_synth_opts *itrace_synth_opts;
+ /** @auxtrace_index: index of AUX area tracing events within a perf.data file. */
struct list_head auxtrace_index;
#ifdef HAVE_LIBTRACEEVENT
+ /** @tevent: handles for libtraceevent and plugins. */
struct trace_event tevent;
#endif
+ /** @time_conv: Holds contents of last PERF_RECORD_TIME_CONV event. */
struct perf_record_time_conv time_conv;
+ /**
+ * @repipe: When set causes certain reading (header and trace events) to
+ * also write events. The written file descriptor must be provided for
+ * the header but is implicitly stdout for trace events.
+ */
bool repipe;
+ /**
+ * @one_mmap: The reader will use a single mmap by default. There may be
+ * multiple data files in particular for aux events. If this is true
+ * then the single big mmap for the data file can be assumed.
+ */
bool one_mmap;
+ /** @one_mmap_addr: Address of initial perf data file reader mmap. */
void *one_mmap_addr;
+ /** @one_mmap_offset: File offset in perf.data file when mapped. */
u64 one_mmap_offset;
+ /** @ordered_events: Used to turn unordered events into ordered ones. */
struct ordered_events ordered_events;
+ /** @data: Optional perf data file being read from. */
struct perf_data *data;
+ /** @tool: callbacks for event handling. */
const struct perf_tool *tool;
+ /**
+ * @bytes_transferred: Used by perf record to count written bytes before
+ * compression.
+ */
u64 bytes_transferred;
+ /**
+ * @bytes_compressed: Used by perf record to count written bytes after
+ * compression.
+ */
u64 bytes_compressed;
+ /** @zstd_data: Owner of global compression state, buffers, etc. */
struct zstd_data zstd_data;
struct decomp_data decomp_data;
struct decomp_data *active_decomp;
--
2.46.0.295.g3b9ea8a38a-goog