Commit Graph

8 Commits

Author SHA1 Message Date
Lluís Vilanova 14101d028d trace: [hmp] Reimplement "trace-event" and "info trace-events" using QMP
Signed-off-by: Lluís Vilanova <vilanova@ac.upc.edu>
Message-id: 20140825112002.31112.60143.stgit@fimbulvetr.bsc.es
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2014-09-26 09:34:38 +01:00
Alexey Kardashevskiy a35d9be622 trace: Replace fprintf with error_report and print location
This replaces fprintf(stderr) with error_report.

This moves local variables to the beginning of the function to comply
with QEMU's coding style.

Suggested-by: Lluís Vilanova <vilanova@ac.upc.edu>
Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2014-06-09 15:43:40 +02:00
Lluís Vilanova 5b808275f3 trace: Multi-backend tracing
Adds support to compile QEMU with multiple tracing backends at the same time.

For example, you can compile QEMU with:

  $ ./configure --enable-trace-backends=ftrace,dtrace

Where 'ftrace' can be handy for having an in-flight record of events, and 'dtrace' can be later used to extract more information from the system.

This patch allows having both available without recompiling QEMU.

Signed-off-by: Lluís Vilanova <vilanova@ac.upc.edu>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2014-06-09 15:43:40 +02:00
Alexey Kardashevskiy 82432638eb trace: Replace error with warning if event is not defined
At the moment QEMU exits if trace point is not defined which makes
a developer life harder if he has to switch between branches with
different traces implemented.

This replaces error+exit wit WARNING if the tracepoint does not exist or
not traceable.

Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2014-06-09 15:43:40 +02:00
Lluís Vilanova b1bae816c4 trace: Provide a detailed event control interface
This interface decouples event obtaining from interaction.

Events can be obtained through three different methods:

* identifier
* name
* simple wildcard pattern

Signed-off-by: Lluís Vilanova <vilanova@ac.upc.edu>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2013-03-28 14:19:57 +01:00
Gerd Hoffmann ddde8acc98 trace: allow disabling events in events file
Disable trace events prefixed with a '-'.  Useful
to enable a group of tracepoints with exceptions,
like this:

  usb_xhci_port_*
  -usb_xhci_port_read

which will enable all xhci port tracepoints except reads.

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2012-11-16 13:12:13 +01:00
Alexey Kardashevskiy 794b1f962e trace: added ability to comment out events in the list
It is convenient for debug to be able to switch on/off some events easily.
The only possibility now is to remove event name from the file completely
and type it again when we want it back.

The patch adds '#' symbol handling as a comment specifier.

Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
2012-07-19 11:30:37 +01:00
Lluís 23d15e860b trace: add "-trace events" argument to control initial state
The "-trace events" argument can be used to provide a file with a list of trace
event names that will be enabled prior to starting execution, thus providing
early tracing.

This saves the user from manually toggling event states through the monitor
interface or whichever backend-specific interface.

Signed-off-by: Lluís Vilanova <vilanova@ac.upc.edu>
2011-09-01 10:34:54 +01:00