Re: Re: [PATCH 3/5] trace-cmd: Support trace-agent of virtio-trace

Hi Steven,

(2012/08/22 22:51), Steven Rostedt wrote:

On Wed, 2012-08-22 at 17:43 +0900, Yoshihiro YUNOMAE wrote:

quoted

Add read path and control path to use trace-agent of virtio-trace.
When we use trace-agent, trace-cmd will be used as follows:
	# AGENT_READ_DIR=/tmp/virtio-trace/tracing \
	  AGENT_CTL=/tmp/virtio-trace/agent-ctl-path.in \
	  TRACING_DIR=/tmp/virtio-trace/debugfs/tracing \\

Ha! You used "TRACING_DIR" but patch one introduces TRACE_DIR. Lets
change this to DEBUG_TRACING_DIR instead anyway.

Oh, sorry for the confusion.

Also, I don't like the generic environment variables. Perhaps
VIRTIO_TRACE_DIR, or AGENT_TRACE_DIR and AGENT_TRACE_CTL. Lets try to
keep the environment namespace sparse.

OK, I'll change these name of environment variables as follows:
    AGENT_READ_DIR
    AGENT_TRACE_CTL
    GUEST_TRACING_DIR

quoted

	  trace-cmd record -e "sched:*"
Here, AGENT_READ_DIR is the path for a reading directory of virtio-trace,
AGENT_CTL is a control path of trace-agent, and TRACING_DIR is a debugfs path
of a guest.

Signed-off-by: Yoshihiro YUNOMAE <redacted>
---

  trace-cmd.h      |    1 +
  trace-recorder.c |   57 +++++++++++++++++++++++++++++++++++++++++++++++++++++-
  trace-util.c     |   18 +++++++++++++++++
  3 files changed, 75 insertions(+), 1 deletions(-)

diff --git a/trace-cmd.h b/trace-cmd.h
index f904dc5..75506ed 100644
--- a/trace-cmd.h
+++ b/trace-cmd.h

@@ -72,6 +72,7 @@ static inline int tracecmd_host_bigendian(void)
  }

  char *tracecmd_find_tracing_dir(void);
+char *guest_agent_tracing_read_dir(void);

  /* --- Opening and Reading the trace.dat file --- */

diff --git a/trace-recorder.c b/trace-recorder.c
index 215affc..3b750e9 100644
--- a/trace-recorder.c
+++ b/trace-recorder.c

@@ -33,6 +33,7 @@
  #include <unistd.h>
  #include <ctype.h>
  #include <errno.h>
+#include <stdbool.h>

  #include "trace-cmd.h"

@@ -43,6 +44,8 @@ struct tracecmd_recorder {
  	int		page_size;
  	int		cpu;
  	int		stop;
+	int		ctl_fd;
+	bool		agent_existing;

Thanks for the reminder. I need to convert a lot to use 'bool' instead.

I'll change 'int' just for flag to use 'bool' as much as possible
after finishing this patch set.

quoted

  };

  void tracecmd_free_recorder(struct tracecmd_recorder *recorder)

@@ -59,11 +62,29 @@ void tracecmd_free_recorder(struct tracecmd_recorder *recorder)
  	free(recorder);
  }

+static char *use_trace_agent_dir(char *ctl_path,
+					struct tracecmd_recorder *recorder)
+{
+	ctl_path = strdup(ctl_path);
+	if (!ctl_path)
+		die("malloc");
+	warning("Use environmental control path: %s\n", ctl_path);

s/Use/Using/

OK, I'll correct this.

Thank you,

-- 
Yoshihiro YUNOMAE
Software Platform Research Dept. Linux Technology Center
Hitachi, Ltd., Yokohama Research Laboratory
E-mail: yoshihiro.yunomae.ez@hitachi.com