This is cleaner, and improves error reporting with -daemonize.
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
Signed-off-by: NDenis V. Lunev <den@openvz.org>
Acked-by: NChristian Borntraeger <borntraeger@de.ibm.com>
Message-id: 1452174932-28657-4-git-send-email-den@openvz.org
Signed-off-by: NStefan Hajnoczi <stefanha@redhat.com>

This is cleaner and has two advantages.  First, it improves error
reporting with -daemonize.  Second, multiple "-trace events" options
now cumulate.
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
Signed-off-by: NDenis V. Lunev <den@openvz.org>
Acked-by: NChristian Borntraeger <borntraeger@de.ibm.com>
Message-id: 1452174932-28657-3-git-send-email-den@openvz.org
Signed-off-by: NStefan Hajnoczi <stefanha@redhat.com>

This is more cache friendly on the fast path, where we already have
the event id available.
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
Signed-off-by: NStefan Hajnoczi <stefanha@redhat.com>

This lets trace_event_get_state_dynamic quickly return false.  Right
now there is hardly any benefit because there are also many assertions
and indirections, but the next patch will streamline all of this.
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
Signed-off-by: NStefan Hajnoczi <stefanha@redhat.com>

Signed-off-by: NGonglei <arei.gonglei@huawei.com>
Reviewed-by: NMarkus Armbruster <armbru@redhat.com>
Signed-off-by: NMichael Tokarev <mjt@tls.msk.ru>

Signed-off-by: NLluís Vilanova <vilanova@ac.upc.edu>
Message-id: 20140825112002.31112.60143.stgit@fimbulvetr.bsc.es
Signed-off-by: NStefan Hajnoczi <stefanha@redhat.com>

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: NLluís Vilanova <vilanova@ac.upc.edu>
Signed-off-by: NAlexey Kardashevskiy <aik@ozlabs.ru>
Signed-off-by: NStefan Hajnoczi <stefanha@redhat.com>

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: NLluís Vilanova <vilanova@ac.upc.edu>
Signed-off-by: NStefan Hajnoczi <stefanha@redhat.com>

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: NAlexey Kardashevskiy <aik@ozlabs.ru>
Signed-off-by: NStefan Hajnoczi <stefanha@redhat.com>

This interface decouples event obtaining from interaction.

Events can be obtained through three different methods:

* identifier
* name
* simple wildcard pattern
Signed-off-by: NLluís Vilanova <vilanova@ac.upc.edu>
Signed-off-by: NStefan Hajnoczi <stefanha@redhat.com>

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: NGerd Hoffmann <kraxel@redhat.com>
Signed-off-by: NStefan Hajnoczi <stefanha@redhat.com>

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: NAlexey Kardashevskiy <aik@ozlabs.ru>
Signed-off-by: NStefan Hajnoczi <stefanha@linux.vnet.ibm.com>

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: NLluís Vilanova <vilanova@ac.upc.edu>