User emulator builds do not have error_report() so it should not be used
by simpletrace.c. In fact, error reporting inside simpletrace.c is
inappropriate and should be done by the caller instead.
This patch moves st_init() error reporting out to its caller,
vl.c:main().
Reported-by: Blue Swirl <blauwirbel@gmail.com>
Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Signed-off-by: Blue Swirl <blauwirbel@gmail.com>
Trace events outside the global mutex cannot be used with the simple
trace backend since it is not thread-safe. There is no check to prevent
them being enabled so people sometimes learn this the hard way.
This patch restructures the simple trace backend with a ring buffer
suitable for multiple concurrent writers. A writeout thread empties the
trace buffer when threshold fill levels are reached. Should the
writeout thread be unable to keep up with trace generation, records will
simply be dropped.
Each time events are dropped a special record is written to the trace
file indicating how many events were dropped. The event ID is
0xfffffffffffffffe and its signature is dropped(uint32_t count).
Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
fprintf_function adds format checking with GCC_FMT_ATTR.
Cc: Blue Swirl <blauwirbel@gmail.com>
Signed-off-by: Stefan Weil <weil@mail.berlios.de>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
There was no warning if a bad trace event name was given to
'trace-event' command, thus the user could think that the command
was successful even if this was not the case.
Print a warning if the user tries to enable a trace event which is not
known.
Acked-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Signed-off-by: Blue Swirl <blauwirbel@gmail.com>
This patch adds the trace-file command:
trace-file [on|off|flush]
Open, close, or flush the trace file. If no argument is given,
the status of the trace file is displayed.
The trace file is turned on by default but is only written out when the
trace buffer becomes full. The flush operation can be used to force
write out at any time.
Turning off the trace file does not change the state of trace events;
tracing will continue to the trace buffer. When the trace file is off,
use "info trace" to display the contents of the trace buffer in memory.
Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
This commit also contains the trace-file sub-command from the following
commit:
commit 5ce8d1a957afae2c52ad748944ce72848ccf57bd
Author: Prerna Saxena <prerna@linux.vnet.ibm.com>
Date: Wed Aug 4 16:23:54 2010 +0530
trace: Add options to specify trace file name at startup and runtime
This patch adds an optional command line switch '-trace' to specify the
filename to write traces to, when qemu starts.
Eg, If compiled with the 'simple' trace backend,
[temp@system]$ qemu -trace FILENAME IMAGE
Allows the binary traces to be written to FILENAME instead of the option
set at config-time.
Also, this adds monitor sub-command 'set' to trace-file commands to
dynamically change trace log file at runtime.
Eg,
(qemu)trace-file set FILENAME
This allows one to set trace outputs to FILENAME from the default
specified at startup.
Signed-off-by: Prerna Saxena <prerna@linux.vnet.ibm.com>
Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
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>
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>
