[1/2] trace-cmd: Move reading of trace.dat options to tracecmd_read_headers()
diff mbox series

Message ID 20200409132825.79475-2-tz.stoyanov@gmail.com
State Accepted
Headers show
Series
  • Split reading the trace.dat options from trace data
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Commit Message

Tzvetomir Stoyanov (VMware) April 9, 2020, 1:28 p.m. UTC
The options section from trace.dat file is logically part of trace headers.
In some use cases it is useful first to read all headers from the file,
analyze the information and do some processing, before reading the tracing
data. In the current implementation, reading of options is just before
reading the tracing data.
Moved the reading of options and a CPU count from read_cpu_data() to
tracecmd_read_headers(). This allows to implement APIs for trace.dat
file reading on stages - headers stage and tracing data stage.

Signed-off-by: Tzvetomir Stoyanov (VMware) <tz.stoyanov@gmail.com>
---
 include/trace-cmd/trace-cmd.h |  1 +
 lib/trace-cmd/trace-input.c   | 89 +++++++++++++++++++++++------------
 2 files changed, 61 insertions(+), 29 deletions(-)

Patch
diff mbox series

diff --git a/include/trace-cmd/trace-cmd.h b/include/trace-cmd/trace-cmd.h
index 595919d5..3f96bbde 100644
--- a/include/trace-cmd/trace-cmd.h
+++ b/include/trace-cmd/trace-cmd.h
@@ -119,6 +119,7 @@  enum {
 	TRACECMD_FL_BUFFER_INSTANCE	= (1 << 1),
 	TRACECMD_FL_LATENCY		= (1 << 2),
 	TRACECMD_FL_IN_USECS		= (1 << 3),
+	TRACECMD_FL_FLYRECORD		= (1 << 4),
 };
 
 struct tracecmd_ftrace {
diff --git a/lib/trace-cmd/trace-input.c b/lib/trace-cmd/trace-input.c
index f04528ae..ee9bfb52 100644
--- a/lib/trace-cmd/trace-input.c
+++ b/lib/trace-cmd/trace-input.c
@@ -141,6 +141,8 @@  struct tracecmd_input {
 
 __thread struct tracecmd_input *tracecmd_curr_thread_handle;
 
+static int read_options_type(struct tracecmd_input *handle);
+
 void tracecmd_set_flag(struct tracecmd_input *handle, int flag)
 {
 	handle->flags |= flag;
@@ -747,6 +749,19 @@  int tracecmd_get_parsing_failures(struct tracecmd_input *handle)
 	return 0;
 }
 
+static int read_cpus(struct tracecmd_input *handle)
+{
+	unsigned int cpus;
+
+	if (read4(handle, &cpus) < 0)
+		return -1;
+
+	handle->cpus = cpus;
+	tep_set_cpus(handle->pevent, handle->cpus);
+
+	return 0;
+}
+
 /**
  * tracecmd_read_headers - read the header information from trace.dat
  * @handle: input handle for the trace.dat file
@@ -784,6 +799,12 @@  int tracecmd_read_headers(struct tracecmd_input *handle)
 	if (read_and_parse_cmdlines(handle) < 0)
 		return -1;
 
+	if (read_cpus(handle) < 0)
+		return -1;
+
+	if (read_options_type(handle) < 0)
+		return -1;
+
 	tep_set_long_size(handle->pevent, handle->long_size);
 
 	return 0;
@@ -2576,23 +2597,13 @@  static int handle_options(struct tracecmd_input *handle)
 	return 0;
 }
 
-static int read_cpu_data(struct tracecmd_input *handle)
+static int read_options_type(struct tracecmd_input *handle)
 {
-	struct tep_handle *pevent = handle->pevent;
-	enum kbuffer_long_size long_size;
-	enum kbuffer_endian endian;
-	unsigned long long size;
-	unsigned long long max_size = 0;
-	unsigned long long pages;
 	char buf[10];
-	int cpus;
-	int cpu;
 
 	if (do_read_check(handle, buf, 10))
 		return -1;
 
-	cpus = handle->cpus;
-
 	/* check if this handles options */
 	if (strncmp(buf, "options", 7) == 0) {
 		if (handle_options(handle) < 0)
@@ -2602,17 +2613,41 @@  static int read_cpu_data(struct tracecmd_input *handle)
 	}
 
 	/*
-	 * Check if this is a latency report or not.
+	 * Check if this is a latency report or flyrecord.
 	 */
-	if (strncmp(buf, "latency", 7) == 0) {
+	if (strncmp(buf, "latency", 7) == 0)
 		handle->flags |= TRACECMD_FL_LATENCY;
+	else if (strncmp(buf, "flyrecord", 9) == 0)
+		handle->flags |= TRACECMD_FL_FLYRECORD;
+	else
+		return -1;
+
+	return 0;
+}
+
+static int read_cpu_data(struct tracecmd_input *handle)
+{
+	struct tep_handle *pevent = handle->pevent;
+	enum kbuffer_long_size long_size;
+	enum kbuffer_endian endian;
+	unsigned long long size;
+	unsigned long long max_size = 0;
+	unsigned long long pages;
+	int cpus;
+	int cpu;
+
+	/*
+	 * Check if this is a latency report or not.
+	 */
+	if (handle->flags & TRACECMD_FL_LATENCY)
 		return 1;
-	}
 
 	/* We expect this to be flyrecord */
-	if (strncmp(buf, "flyrecord", 9) != 0)
+	if (!(handle->flags & TRACECMD_FL_FLYRECORD))
 		return -1;
 
+	cpus = handle->cpus;
+
 	handle->cpu_data = malloc(sizeof(*handle->cpu_data) * handle->cpus);
 	if (!handle->cpu_data)
 		return -1;
@@ -2795,15 +2830,8 @@  static int read_and_parse_trace_clock(struct tracecmd_input *handle,
 int tracecmd_init_data(struct tracecmd_input *handle)
 {
 	struct tep_handle *pevent = handle->pevent;
-	unsigned int cpus;
 	int ret;
 
-	if (read4(handle, &cpus) < 0)
-		return -1;
-	handle->cpus = cpus;
-
-	tep_set_cpus(pevent, handle->cpus);
-
 	ret = read_cpu_data(handle);
 	if (ret < 0)
 		return ret;
@@ -3579,25 +3607,28 @@  tracecmd_buffer_instance_handle(struct tracecmd_input *handle, int indx)
 	if (ret < 0) {
 		warning("could not seek to buffer %s offset %ld\n",
 			buffer->name, buffer->offset);
-		tracecmd_close(new_handle);
-		return NULL;
+		goto error;
 	}
 
-	ret = read_cpu_data(new_handle);
+	ret = read_options_type(new_handle);
+	if (!ret)
+		ret = read_cpu_data(new_handle);
 	if (ret < 0) {
 		warning("failed to read sub buffer %s\n", buffer->name);
-		tracecmd_close(new_handle);
-		return NULL;
+		goto error;
 	}
 
 	ret = lseek64(handle->fd, offset, SEEK_SET);
 	if (ret < 0) {
 		warning("could not seek to back to offset %ld\n", offset);
-		tracecmd_close(new_handle);
-		return NULL;
+		goto error;
 	}
 
 	return new_handle;
+
+error:
+	tracecmd_close(new_handle);
+	return NULL;
 }
 
 int tracecmd_is_buffer_instance(struct tracecmd_input *handle)