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2017-09-19Convert remaining error_report() to warn_report()Alistair Francis
In a previous patch (3dc6f8693694a649a9c83f1e2746565b47683923) we converted uses of error_report("warning:"... to use warn_report() instead. This was to help standardise on a single method of printing warnings to the user. There appears to have been some cases that slipped through in patch sets applied around the same time, this patch catches the few remaining cases. All of the warnings were changed using this command: find ./* -type f -exec sed -i \ 's|error_report(".*warning[,:] |warn_report("|Ig' {} + Indentation fixed up manually afterwards. Two messages were manually fixed up as well. Signed-off-by: Alistair Francis <alistair.francis@xilinx.com> Cc: Kevin Wolf <kwolf@redhat.com> Cc: Max Reitz <mreitz@redhat.com> Cc: Christian Borntraeger <borntraeger@de.ibm.com> Cc: Cornelia Huck <cohuck@redhat.com> Cc: Alexander Graf <agraf@suse.de> Cc: Richard Henderson <rth@twiddle.net> Cc: Stefan Hajnoczi <stefanha@redhat.com> Acked-by: Cornelia Huck <cohuck@redhat.com> Reviewed-by: Markus Armbruster <armbru@redhat.com> Message-Id: <eec8cba0d5434bd828639e5e45f12182490ff47d.1505158760.git.alistair.francis@xilinx.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2017-07-17trace: Allocate cpu->trace_dstate in placeLluís Vilanova
There's little point in dynamically allocating the bitmap if we know at compile-time the max number of events we want to support. Thus, make room in the struct for the bitmap, which will make things easier later: this paves the way for upcoming changes, in which we'll use a u32 to fully capture cpu->trace_dstate. This change also increases performance by saving a dereference and improving locality--note that this is important since upcoming work makes reading this bitmap fairly common. Signed-off-by: Emilio G. Cota <cota@braap.org> Reviewed-by: Lluís Vilanova <vilanova@ac.upc.edu> Signed-off-by: Lluís Vilanova <vilanova@ac.upc.edu> Message-id: 149915725977.6295.15069969323605305641.stgit@frigg.lan Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2017-07-13Convert error_report() to warn_report()Alistair Francis
Convert all uses of error_report("warning:"... to use warn_report() instead. This helps standardise on a single method of printing warnings to the user. All of the warnings were changed using these two commands: find ./* -type f -exec sed -i \ 's|error_report(".*warning[,:] |warn_report("|Ig' {} + Indentation fixed up manually afterwards. The test-qdev-global-props test case was manually updated to ensure that this patch passes make check (as the test cases are case sensitive). Signed-off-by: Alistair Francis <alistair.francis@xilinx.com> Suggested-by: Thomas Huth <thuth@redhat.com> Cc: Jeff Cody <jcody@redhat.com> Cc: Kevin Wolf <kwolf@redhat.com> Cc: Max Reitz <mreitz@redhat.com> Cc: Ronnie Sahlberg <ronniesahlberg@gmail.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Peter Lieven <pl@kamp.de> Cc: Josh Durgin <jdurgin@redhat.com> Cc: "Richard W.M. Jones" <rjones@redhat.com> Cc: Markus Armbruster <armbru@redhat.com> Cc: Peter Crosthwaite <crosthwaite.peter@gmail.com> Cc: Richard Henderson <rth@twiddle.net> Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com> Cc: Greg Kurz <groug@kaod.org> Cc: Rob Herring <robh@kernel.org> Cc: Peter Maydell <peter.maydell@linaro.org> Cc: Peter Chubb <peter.chubb@nicta.com.au> Cc: Eduardo Habkost <ehabkost@redhat.com> Cc: Marcel Apfelbaum <marcel@redhat.com> Cc: "Michael S. Tsirkin" <mst@redhat.com> Cc: Igor Mammedov <imammedo@redhat.com> Cc: David Gibson <david@gibson.dropbear.id.au> Cc: Alexander Graf <agraf@suse.de> Cc: Gerd Hoffmann <kraxel@redhat.com> Cc: Jason Wang <jasowang@redhat.com> Cc: Marcelo Tosatti <mtosatti@redhat.com> Cc: Christian Borntraeger <borntraeger@de.ibm.com> Cc: Cornelia Huck <cohuck@redhat.com> Cc: Stefan Hajnoczi <stefanha@redhat.com> Acked-by: David Gibson <david@gibson.dropbear.id.au> Acked-by: Greg Kurz <groug@kaod.org> Acked-by: Cornelia Huck <cohuck@redhat.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Reviewed by: Peter Chubb <peter.chubb@data61.csiro.au> Acked-by: Max Reitz <mreitz@redhat.com> Acked-by: Marcel Apfelbaum <marcel@redhat.com> Message-Id: <e1cfa2cd47087c248dd24caca9c33d9af0c499b0.1499866456.git.alistair.francis@xilinx.com> Reviewed-by: Markus Armbruster <armbru@redhat.com> Signed-off-by: Markus Armbruster <armbru@redhat.com>
2017-01-31trace: switch to modular code generation for sub-directoriesDaniel P. Berrange
Introduce rules in the top level Makefile that are able to generate trace.[ch] files in every subdirectory which has a trace-events file. The top level directory is handled specially, so instead of creating trace.h, it creates trace-root.h. This allows sub-directories to include the top level trace-root.h file, without ambiguity wrt to the trace.g file in the current sub-dir. Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Signed-off-by: Daniel P. Berrange <berrange@redhat.com> Message-id: 20170125161417.31949-7-berrange@redhat.com Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2017-01-16trace: Add event "guest_cpu_exit"Lluís Vilanova
Signals the hot-unplugging of a virtual (guest) CPU. Signed-off-by: Lluís Vilanova <vilanova@ac.upc.edu> Message-id: 148278748597.1404.10546320797997984932.stgit@fimbulvetr.bsc.es Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2017-01-16trace: Fix dynamic event state on vCPU hot-unplugLluís Vilanova
We need to disable per-vCPU events on a vCPU that is hot-unplugged to keep the dynamic event state global counters consistent. Signed-off-by: Lluís Vilanova <vilanova@ac.upc.edu> Message-id: 148278748055.1404.1570530281528619895.stgit@fimbulvetr.bsc.es Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2016-10-12trace: dynamically allocate event IDs at runtimeDaniel P. Berrange
Instead of having the code generator assign event IDs and event VCPU IDs, assign them when the events are registered at runtime. This will allow code to be generated from individual trace-events without having to figure out globally unique numbering at build time. Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Reviewed-by: Lluís Vilanova <vilanova@ac.upc.edu> Signed-off-by: Daniel P. Berrange <berrange@redhat.com> Message-id: 1475588159-30598-16-git-send-email-berrange@redhat.com Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2016-10-12trace: dynamically allocate trace_dstate in CPUStateDaniel P. Berrange
The CPUState struct has a bitmap tracking which VCPU events are currently active. This is indexed based on the event ID values, and sized according the maximum TraceEventVCPUID enum value. When we start dynamically assigning IDs at runtime, we can't statically declare a bitmap without making an assumption about the max event count. This problem can be solved by dynamically allocating the per-CPU dstate bitmap. Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Reviewed-by: Lluís Vilanova <vilanova@ac.upc.edu> Signed-off-by: Daniel P. Berrange <berrange@redhat.com> Message-id: 1475588159-30598-15-git-send-email-berrange@redhat.com Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2016-10-12trace: provide mechanism for registering trace eventsDaniel P. Berrange
Remove the notion of there being a single global array of trace events, by introducing a method for registering groups of events. The module_call_init() needs to be invoked at the start of any program that wants to make use of the trace support. Currently this covers system emulators qemu-nbd, qemu-img and qemu-io. [Squashed the following fix from Daniel P. Berrange <berrange@redhat.com>: linux-user/bsd-user: initialize trace events subsystem The bsd-user/linux-user programs make use of the CPU emulation code and this now requires that the trace events subsystem is enabled, otherwise it'll crash trying to allocate an empty trace events bitmap for the CPU object. --Stefan] Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Reviewed-by: Lluís Vilanova <vilanova@ac.upc.edu> Signed-off-by: Daniel P. Berrange <berrange@redhat.com> Message-id: 1475588159-30598-14-git-send-email-berrange@redhat.com Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2016-10-12trace: remove the TraceEventID and TraceEventVCPUID enumsDaniel P. Berrange
The TraceEventID and TraceEventVCPUID enums constants are no longer actually used for anything critical. The TRACE_EVENT_COUNT limit is used to determine the size of the TraceEvents array, and can be removed if we just NULL terminate the array instead. The TRACE_VCPU_EVENT_COUNT limit is used as a magic value for marking non-vCPU events, and also for declaring the size of the trace dstate mask in the CPUState struct. The former usage can be replaced by a dedicated constant TRACE_EVENT_VCPU_NONE, defined as (uint32_t)-1. For the latter usage, we can simply define a constant for the number of VCPUs, avoiding the need for the full enum. The only other usages of the enum values can be replaced by accesing the id/vcpu_id fields via the named TraceEvent structs. Reviewed-by: Lluís Vilanova <vilanova@ac.upc.edu> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Signed-off-by: Daniel P. Berrange <berrange@redhat.com> Message-id: 1475588159-30598-11-git-send-email-berrange@redhat.com Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2016-10-12trace: give each trace event a named TraceEvent structDaniel P. Berrange
Currently we only expose a TraceEvent array, which must be indexed via the TraceEventID enum constants. This changes the generator to expose a named TraceEvent instance for each event, with an _EVENT suffix. Reviewed-by: Lluís Vilanova <vilanova@ac.upc.edu> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Signed-off-by: Daniel P. Berrange <berrange@redhat.com> Message-id: 1475588159-30598-10-git-send-email-berrange@redhat.com Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2016-10-12trace: remove global 'uint16 dstate[]' arrayDaniel P. Berrange
Instead of having a global dstate array, declare a single 'uint16 TRACE_${EVENT_NAME}_DSTATE' variable for each trace event. Record a pointer to this variable in the TraceEvent struct too. By turning trace_event_get_state_dynamic_by_id into a macro, this still hits the fast path, and cache affinity is ensured by declaring all the uint16 vars adjacent to each other. Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Reviewed-by: Lluís Vilanova <vilanova@ac.upc.edu> Signed-off-by: Daniel P. Berrange <berrange@redhat.com> Message-id: 1475588159-30598-7-git-send-email-berrange@redhat.com Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2016-10-12trace: remove some now unused functionsDaniel P. Berrange
The trace_event_count, trace_event_id and trace_event_pattern methods are no longer required now that everything is using the iterator APIs The trace_event_set_state and trace_event_set_vcpu_state macros were also unused. Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Reviewed-by: Lluís Vilanova <vilanova@ac.upc.edu> Signed-off-by: Daniel P. Berrange <berrange@redhat.com> Message-id: 1475588159-30598-6-git-send-email-berrange@redhat.com Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2016-10-12trace: convert code to use event iteratorsDaniel P. Berrange
This converts the HMP/QMP monitor API implementations and some internal trace control methods to use the new trace event iterator APIs. Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Signed-off-by: Daniel P. Berrange <berrange@redhat.com> Reviewed-by: Lluís Vilanova <vilanova@ac.upc.edu> Message-id: 1475588159-30598-5-git-send-email-berrange@redhat.com Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2016-10-12trace: add trace event iterator APIsDaniel P. Berrange
Currently methods which want to iterate over trace events, do so using the trace_event_count() and trace_event_id() methods. This leaks the concept of a single ID enum to the callers. There is an alternative trace_event_pattern() method which can be used in an iteration context, but its design is stateless, so is not easy to expand it in the future. This defines a formal iterator API will provide a future- proof way of iterating over events. The iterator is also able to apply a pattern match filter to events, further removing the need for the pattern Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Reviewed-by: Lluís Vilanova <vilanova@ac.upc.edu> Signed-off-by: Daniel P. Berrange <berrange@redhat.com> Message-id: 1475588159-30598-4-git-send-email-berrange@redhat.com Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2016-09-28trace: Properly initialize dynamic event states in hot-plugged vCPUsLluís Vilanova
Every time a vCPU is hot-plugged, it will "inherit" its tracing state from the global state array. That is, if *any* existing vCPU has an event enabled, new vCPUs will have too. Signed-off-by: Lluís Vilanova <vilanova@ac.upc.edu> Message-id: 147428970768.15111.7664565956870423529.stgit@fimbulvetr.bsc.es Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2016-09-05trace: Remove 'trace_events_dstate_init'Lluís Vilanova
Removes the event state array used for early initialization. Since only events with the "vcpu" property need a late initialization fixup, threats their initialization specially. Assumes that the user won't touch the state of "vcpu" events between early and late initialization (e.g., through QMP). Signed-off-by: Lluís Vilanova <vilanova@ac.upc.edu> Message-id: 147194273191.26836.14423079546263831356.stgit@fimbulvetr.bsc.es Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2016-09-05trace: add syslog tracing backendPaul Durrant
This patch adds a tracing backend which sends output using syslog(). The syslog backend is limited to POSIX compliant systems. openlog() is called with facility set to LOG_DAEMON, with the LOG_PID option. Trace events are logged at level LOG_INFO. Signed-off-by: Paul Durrant <paul.durrant@citrix.com> Message-id: 1470318254-29989-1-git-send-email-paul.durrant@citrix.com Cc: Stefan Hajnoczi <stefanha@redhat.com> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2016-07-18trace: Add per-vCPU tracing states for events with the 'vcpu' propertyLluís Vilanova
Each vCPU gets a 'trace_dstate' bitmap to control the per-vCPU dynamic tracing state of events with the 'vcpu' property. Signed-off-by: Lluís Vilanova <vilanova@ac.upc.edu> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2016-06-28trace: move qemu_trace_opts to trace/control.cDenis V. Lunev
The patch also creates trace_opt_parse() helper in trace/control.c to reuse this code in next patches for qemu-nbd and qemu-io. The patch also makes trace_init_events() static, as this call is not used outside the module anymore. Signed-off-by: Denis V. Lunev <den@openvz.org> Reviewed-by: Eric Blake <eblake@redhat.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Message-id: 1466174654-30130-4-git-send-email-den@openvz.org CC: Paolo Bonzini <pbonzini@redhat.com> CC: Stefan Hajnoczi <stefanha@redhat.com> CC: Kevin Wolf <kwolf@redhat.com> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2016-06-20log: Fix qemu_set_log_filename() error handlingMarkus Armbruster
When qemu_set_log_filename() detects an invalid file name, it reports an error, closes the log file (if any), and starts logging to stderr (unless daemonized or nothing is being logged). This is wrong. Asking for an invalid log file on the command line should be fatal. Asking for one in the monitor should fail without messing up an existing logfile. Fix by converting qemu_set_log_filename() to Error. Pass it &error_fatal, except for hmp_logfile report errors. This also permits testing without a subprocess, so do that. Signed-off-by: Markus Armbruster <armbru@redhat.com> Message-Id: <1466011636-6112-4-git-send-email-armbru@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com>
2016-03-31trace: do not always call exit() in trace_enable_eventsDenis V. Lunev
The problem is that virsh qemu-monitor-command --hmp VM log trace:help forces QEMU to exit even when running VM normally. Signed-off-by: Denis V. Lunev <den@openvz.org> Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> Message-id: 1458128212-4197-2-git-send-email-den@openvz.org CC: Stefan Hajnoczi <stefanha@redhat.com> Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2016-03-22util: move declarations out of qemu-common.hVeronia Bahaa
Move declarations out of qemu-common.h for functions declared in utils/ files: e.g. include/qemu/path.h for utils/path.c. Move inline functions out of qemu-common.h and into new files (e.g. include/qemu/bcd.h) Signed-off-by: Veronia Bahaa <veroniabahaa@gmail.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-02-04all: Clean up includesPeter Maydell
Clean up includes so that osdep.h is included first and headers which it implies are not included manually. This commit was created with scripts/clean-includes. Signed-off-by: Peter Maydell <peter.maydell@linaro.org> Message-id: 1454089805-5470-16-git-send-email-peter.maydell@linaro.org
2016-02-03trace: convert stderr backend to logPaolo Bonzini
[Also update .travis.yml --enable-trace-backends=stderr --Stefan] Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Denis V. Lunev <den@openvz.org> Acked-by: Christian Borntraeger <borntraeger@de.ibm.com> Message-id: 1452174932-28657-10-git-send-email-den@openvz.org Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2016-02-03trace: add "-trace help"Paolo Bonzini
Print a list of trace points Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Denis V. Lunev <den@openvz.org> Acked-by: Christian Borntraeger <borntraeger@de.ibm.com> Message-id: 1452174932-28657-7-git-send-email-den@openvz.org Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2016-02-03trace: add "-trace enable=..."Paolo Bonzini
Allow enabling events without going through a file, for example: qemu-system-x86_64 -trace bdrv_aio_writev -trace bdrv_aio_readv or with globbing too: qemu-system-x86_64 -trace 'bdrv_aio_*' if an appropriate backend is enabled (simple, stderr, ftrace). Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Denis V. Lunev <den@openvz.org> Acked-by: Christian Borntraeger <borntraeger@de.ibm.com> Message-id: 1452174932-28657-6-git-send-email-den@openvz.org Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2016-02-03trace: split trace_init_file out of trace_init_backendsPaolo Bonzini
This is cleaner, and improves error reporting with -daemonize. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Denis V. Lunev <den@openvz.org> Acked-by: Christian Borntraeger <borntraeger@de.ibm.com> Message-id: 1452174932-28657-4-git-send-email-den@openvz.org Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2016-02-03trace: split trace_init_events out of trace_init_backendsPaolo Bonzini
This is cleaner and has two advantages. First, it improves error reporting with -daemonize. Second, multiple "-trace events" options now cumulate. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Denis V. Lunev <den@openvz.org> Acked-by: Christian Borntraeger <borntraeger@de.ibm.com> Message-id: 1452174932-28657-3-git-send-email-den@openvz.org Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2016-02-03trace: track enabled events in a separate arrayPaolo Bonzini
This is more cache friendly on the fast path, where we already have the event id available. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2016-02-03trace: count number of enabled eventsPaolo Bonzini
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: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2015-03-10Remove superfluous '\n' around error_report()Gonglei
Signed-off-by: Gonglei <arei.gonglei@huawei.com> Reviewed-by: Markus Armbruster <armbru@redhat.com> Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>
2014-09-26trace: [hmp] Reimplement "trace-event" and "info trace-events" using QMPLluís Vilanova
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>
2014-06-09trace: Replace fprintf with error_report and print locationAlexey Kardashevskiy
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>
2014-06-09trace: Multi-backend tracingLluís Vilanova
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>
2014-06-09trace: Replace error with warning if event is not definedAlexey Kardashevskiy
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>
2013-03-28trace: Provide a detailed event control interfaceLluís Vilanova
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>
2012-11-16trace: allow disabling events in events fileGerd Hoffmann
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>
2012-07-19trace: added ability to comment out events in the listAlexey Kardashevskiy
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>
2011-09-01trace: add "-trace events" argument to control initial stateLluís
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>