[31/87] trace-cmd library: Fit CPU latency trace data in the new trace file version 7 format

Commit Message

Tzvetomir Stoyanov (VMware) July 28, 2021, 1:31 p.m. UTC

Trace file version 7 format is based on sections. To fit the latency
trace data in this structure, a new section and option for it is
defined:
  BUFFER_LAT
It is similar to the BUFFER section which holds the flyrecord data, but
has a latency specific design. The BUFFER_LAT section has:
 - section header, as all other sections
 - compression of the trace data, optional
 - corresponding trace option, pointing to the section

Signed-off-by: Tzvetomir Stoyanov (VMware) <[e-mail]>
---
 .../include/private/trace-cmd-private.h       |  3 +-
 lib/trace-cmd/trace-output.c                  | 36 ++++++++++++++++---
 tracecmd/trace-record.c                       |  2 +-
 3 files changed, 35 insertions(+), 6 deletions(-)

Patch

diff --git a/lib/trace-cmd/include/private/trace-cmd-private.h b/lib/trace-cmd/include/private/trace-cmd-private.h
index 4e718c40..f2868576 100644
--- a/lib/trace-cmd/include/private/trace-cmd-private.h
+++ b/lib/trace-cmd/include/private/trace-cmd-private.h
@@ -135,6 +135,7 @@  enum {
 	TRACECMD_OPTION_TIME_SHIFT,
 	TRACECMD_OPTION_GUEST,
 	TRACECMD_OPTION_TSC2NSEC,
+	TRACECMD_OPTION_BUFFER_LAT,
 	TRACECMD_OPTION_HEADER_INFO,
 	TRACECMD_OPTION_FTRACE_EVENTS,
 	TRACECMD_OPTION_EVENT_FORMATS,
@@ -294,7 +295,7 @@  int tracecmd_output_write_headers(struct tracecmd_output *handler,
 				  struct tracecmd_event_list *list);
 
 struct tracecmd_output *tracecmd_create_file_latency(const char *output_file, int cpus,
-						     int file_version);
+						     int file_version, const char *compression);
 struct tracecmd_output *tracecmd_create_init_fd(int fd);
 
 struct tracecmd_output *tracecmd_create_init_file(const char *output_file);
diff --git a/lib/trace-cmd/trace-output.c b/lib/trace-cmd/trace-output.c
index e027dd93..e6dadba5 100644
--- a/lib/trace-cmd/trace-output.c
+++ b/lib/trace-cmd/trace-output.c
@@ -2030,9 +2030,11 @@  out_add_buffer_option_v7(struct tracecmd_output *handle, const char *name,
 }
 
 struct tracecmd_output *tracecmd_create_file_latency(const char *output_file, int cpus,
-						     int file_version)
+						     int file_version, const char *compression)
 {
+	enum tracecmd_section_flags flags = 0;
 	struct tracecmd_output *handle;
+	tsize_t offset;
 	char *path;
 	int fd;
 
@@ -2045,6 +2047,12 @@  struct tracecmd_output *tracecmd_create_file_latency(const char *output_file, in
 		goto out_free;
 	if (file_version && tracecmd_output_set_version(handle, file_version))
 		goto out_free;
+	if (compression) {
+		if (tracecmd_output_set_compression(handle, compression))
+			goto out_free;
+	} else if (file_version >= 7) {
+		tracecmd_output_set_compression(handle, "any");
+	}
 	if (tracecmd_output_write_init(handle))
 		goto out_free;
 	if (tracecmd_output_write_headers(handle, NULL))
@@ -2057,7 +2065,8 @@  struct tracecmd_output *tracecmd_create_file_latency(const char *output_file, in
 
 	if (tracecmd_write_cpus(handle, cpus) < 0)
 		goto out_free;
-
+	if (tracecmd_write_buffer_info(handle) < 0)
+		goto out_free;
 	if (tracecmd_write_options(handle) < 0)
 		goto out_free;
 
@@ -2067,23 +2076,42 @@  struct tracecmd_output *tracecmd_create_file_latency(const char *output_file, in
 		goto out_free;
 	}
 
-	if (do_write_check(handle, "latency  ", 10))
+	if (handle->file_version < 7 && do_write_check(handle, "latency  ", 10))
 		goto out_free;
 
 	path = get_tracing_file(handle, "trace");
 	if (!path)
 		goto out_free;
 
+	offset = do_lseek(handle, 0, SEEK_CUR);
+	if (handle->file_version >= 7 &&
+	    !out_add_buffer_option_v7(handle, "", TRACECMD_OPTION_BUFFER_LAT, offset, 0, NULL))
+		goto out_free;
+	if (handle->compress)
+		flags |= TRACECMD_SEC_FL_COMPRESS;
+
+	offset = out_write_section_header(handle, TRACECMD_OPTION_BUFFER_LAT,
+					  "buffer latency", flags, false);
+
 	copy_file_compress(handle, path, NULL);
+	if (out_update_section_header(handle, offset))
+		goto out_free;
 
 	put_tracing_file(path);
 
 	handle->file_state = TRACECMD_FILE_CPU_LATENCY;
 
+	if (tracecmd_get_out_file_version(handle) >= 7)
+		tracecmd_write_options(handle);
+
 	return handle;
 
 out_free:
-	tracecmd_output_close(handle);
+	if (handle)
+		tracecmd_output_close(handle);
+	else
+		close(fd);
+	unlink(output_file);
 	return NULL;
 }
 
diff --git a/tracecmd/trace-record.c b/tracecmd/trace-record.c
index f8c1c090..2e8db8a4 100644
--- a/tracecmd/trace-record.c
+++ b/tracecmd/trace-record.c
@@ -4531,7 +4531,7 @@  static void record_data(struct common_record_context *ctx)
 
 	if (latency) {
 		handle = tracecmd_create_file_latency(ctx->output, local_cpu_count,
-						      ctx->file_version);
+						      ctx->file_version, ctx->compression);
 		tracecmd_set_quiet(handle, quiet);
 	} else {
 		if (!local_cpu_count)