Commit Graph

3 Commits

Author SHA1 Message Date
Prerna Saxena 9410b56c82 trace: Specify trace file name
Allow users to specify a file for trace-outputs at configuration.
Also, allow trace files to be annotated by <pid> so each qemu instance has
unique traces.

The trace file name can be passed as a config option:
--trace-file=/path/to/file
(Default: trace )
At runtime, the pid of the qemu process is appended to the filename so
that mutiple qemu instances do not have overlapping logs.

Eg : trace-1234 for qemu launched with pid 1234.

I have yet to test this on windows. getpid() is used at many places
in code(including vnc.c), so I'm hoping this would be okay too.

Edited-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
2010-09-09 16:22:44 -05:00
Prerna Saxena 22890ab5e8 trace: Support for dynamically enabling/disabling trace events
This patch adds support for dynamically enabling/disabling of trace events.
This is done by internally maintaining each trace event's state, and
permitting logging of data from a trace event only if it is in an
'active' state.

Monitor commands added :
1) info trace-events 		: to view all available trace events and
				  their state.
2) trace-event NAME on|off 	: to enable/disable data logging from a
				  given trace event.
				  Eg, trace-event paio_submit off
				  	disables logging of data when
					paio_submit is hit.

By default, all trace-events are disabled. One can enable desired trace-events
via the monitor.

Signed-off-by: Prerna Saxena <prerna@linux.vnet.ibm.com>
Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>

trace: Monitor command 'info trace'

Monitor command 'info trace' to display contents of trace buffer

Signed-off-by: Prerna Saxena <prerna@linux.vnet.ibm.com>
Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>

trace: Remove monitor.h dependency from simpletrace

User-mode targets don't have a monitor so the simple trace backend
currently does not build on those targets.  This patch abstracts the
monitor printing interface so there is no direct coupling between
simpletrace and the monitor.

Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
2010-09-09 16:22:44 -05:00
Stefan Hajnoczi 26f7227bfe trace: Add simple built-in tracing backend
This patch adds a simple tracer which produces binary trace files.  To
try out the simple backend:

$ ./configure --trace-backend=simple
$ make

After running QEMU you can pretty-print the trace:

$ ./simpletrace.py trace-events trace.log

The output of simpletrace.py looks like this:

  qemu_realloc 0.699 ptr=0x24363f0 size=0x3 newptr=0x24363f0
  qemu_free 0.768 ptr=0x24363f0
  ^           ^---- timestamp delta (us)
  |____ trace event name

Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>

trace: Make trace record fields 64-bit

Explicitly use 64-bit fields in trace records so that timestamps and
magic numbers work for 32-bit host builds.

Includes fixes from Prerna Saxena <prerna@linux.vnet.ibm.com>.

Signed-off-by: Prerna Saxena <prerna@linux.vnet.ibm.com>
Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
2010-09-09 16:22:44 -05:00