Commit Graph

61 Commits

Author SHA1 Message Date
Stefan Hajnoczi cef517ca4b trace: add make dependencies on tracetool source
Patches that change tracetool can break the build if old build output
files are lying around.

This happens because the Makefile does not specify dependencies on
tracetool.  The build will use old object files that do not match the
current source code.

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2016-01-07 16:59:56 +08:00
Stefan Hajnoczi 9967e4fec0 trace: fix make foo-timestamp rules
The Makefile uses intermediate timestamp files to avoid rebuilding if
tracetool output is unchanged.

Timestamps are implemented incorrectly.  This was fixed for rules.mak in
commit 4b25966ab9 ("rules.mak: cleanup
config generation rules") but never fixed in trace/Makefile.objs.

The problem with the old timestamp implementation was that make doesn't
notice the updated file modification time until the next time it is run.
It was necessary to run make twice in a row to achieve a full rebuild.

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2016-01-07 16:59:38 +08:00
Stefan Weil 857a0e387a trace/simple: Fix warning and wrong trace file name for MinGW
On Windows, getpid() always returns an int value, but pid_t (which is
expected by the format string) is either a 32 bit or a 64 bit value.

Without a type cast (or a modified format string), the compiler prints
a warning when building for 64 bit Windows and the resulting trace_file_name
will include a wrong pid:

trace/simple.c:332:9: warning:
 format ‘%lld’ expects argument of type ‘long long int’,
 but argument 2 has type ‘int’ [-Wformat=]

Signed-off-by: Stefan Weil <sw@weilnetz.de>
2015-11-30 06:47:02 +01:00
Gonglei 81b07353c5 Remove superfluous '\n' around error_report()
Signed-off-by: Gonglei <arei.gonglei@huawei.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>
2015-03-10 08:15:33 +03:00
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
Lluís Vilanova 1dde0f48d5 trace: [qmp] Add commands to query and control event tracing state
Signed-off-by: Lluís Vilanova <vilanova@ac.upc.edu>
Message-id: 20140825111957.31112.31733.stgit@fimbulvetr.bsc.es
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2014-09-26 09:34:38 +01:00
Fam Zheng ddbc41de38 trace: Only link generated-tracers.o with "simple" backend
In any other cases the object file is effectively empty, which is
disliked by ranlib and nm on Mac OS X.

Reported-by: Peter Maydell <peter.maydell@linaro.org>
Tested-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-09-09 13:13:05 +02:00
Lluís Vilanova 465830fbd9 trace: [tcg] Generate TCG tracing routines
Generate header "trace/generated-tcg-tracers.h" with the necessary routines for
tracing events in guest code:

* trace_${event}_tcg

  Convenience wrapper that calls the translation-time tracer
  'trace_${event}_trans', and calls 'gen_helper_trace_${event}_exec to
  generate the TCG code to later trace the event at execution time.

Signed-off-by: Lluís Vilanova <vilanova@ac.upc.edu>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2014-08-12 14:26:12 +01:00
Lluís Vilanova f4654226d4 trace: [tcg] Define TCG tracing helper routine wrappers
Generates header "trace/generated-helpers-wrappers.h" with definitions for TCG
helper wrappers.

These wrappers ('gen_helper_trace_${event}_exec_wrapper') transform mixed native
and TCG argument types to TCG types and call the actual TCG helpers
('gen_helper_trace_${event}_exec_proxy').

Signed-off-by: Lluís Vilanova <vilanova@ac.upc.edu>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2014-08-12 14:26:12 +01:00
Lluís Vilanova 341ea69185 trace: [tcg] Define TCG tracing helper routines
Generates file "trace/generated-helpers.c" with TCG helper definitions to trace
events in guest code at execution time.

The helpers ('helper_trace_${event}_exec_proxy') cast the TCG-compatible native
argument types to their original types (as defined in "trace-events") and call
the tracing routine ('trace_${event}_exec').

Signed-off-by: Lluís Vilanova <vilanova@ac.upc.edu>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2014-08-12 14:26:12 +01:00
Lluís Vilanova 707c8a98e4 trace: [tcg] Declare TCG tracing helper routines
Generates file "trace/generated-helpers.h" with TCG helper declarations to trace
events in guest code at execution time ('trace_${event}_exec_proxy').

Signed-off-by: Lluís Vilanova <vilanova@ac.upc.edu>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2014-08-12 14:26:12 +01:00
Michael Tokarev 86946a2d83 glib-compat.h: add new thread API emulation on top of pre-2.31 API
Thread API changed in glib-2.31 significantly.  Before that version,
conditionals and mutexes were only allocated dynamically, using
_new()/_free() interface.  in 2.31 and up, they're allocated statically
as regular variables, and old interface is deprecated.

(Note: glib docs says the new interface is available since version
2.32, but it was actually introduced in version 2.31).

Create the new interface using old primitives, by providing non-opaque
definitions of the base types (GCond and GMutex) using GOnces.

Replace #ifdeffery around GCond and GMutex in trace/simple.c and
coroutine-gthread.c too because it does not work anymore with the new
glib-compat.h.

Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
[Use GOnce to support lazy initialization; introduce CompatGMutex
 and CompatGCond.  - Paolo]
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-06-10 07:44:01 +02:00
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
Stefan Hajnoczi 26896cbf35 trace: add pid field to simpletrace record
It is useful to know the QEMU process ID when working with traces from
multiple VMs.  Although the trace filename may contain the pid, tools
that aggregate traces or even trace globally need somewhere to record
the pid.

There is a reserved field in the trace event header struct that we can
use.

It is not necessary to bump the simpletrace file format version number
because it has already been incremented for the QEMU 2.1 release cycle
in commit "trace: [simple] Bump up log version number".

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2014-06-09 15:43:40 +02:00
Lluís Vilanova 1dad2ce973 trace: [tracetool] Minimize the amount of per-backend code
Backends now only contain the essential backend-specific code, and most of the work is moved to frontend code.

Signed-off-by: Lluís Vilanova <vilanova@ac.upc.edu>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2014-05-07 19:07:18 +02:00
Lluís Vilanova ef0bd3bba6 trace: [simple] Bump up log version number
The following tracetool cleanup changes the event numbering policy.

Signed-off-by: Lluís Vilanova <vilanova@ac.upc.edu>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2014-05-07 19:07:18 +02:00
Stefan Hajnoczi ae2990c259 osdep: initialize glib threads in all QEMU tools
glib versions prior to 2.31.0 require an explicit g_thread_init() call
to enable multi-threading.

Failure to initialize threading causes glib to take single-threaded code
paths without synchronization.  For example, the g_slice allocator will
crash due to race conditions.

Fix this for all QEMU tool programs (qemu-nbd, qemu-io, qemu-img) by
moving the g_thread_init() call from vl.c:main() into a new
osdep.c:thread_init() constructor function.

thread_init() has __attribute__((constructor)) and is automatically
invoked by the runtime during startup.

We can now drop the "simple" trace backend's g_thread_init() call since
thread_init() already called it.

Note that we must keep coroutine-gthread.c's g_thread_init() call which
is located in a constructor function.  There is no guarantee for
constructor function ordering so thread_init() may only be called later.

Reported-by: Mario de Chenno <mario.dechenno@unina2.it>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2014-03-25 13:39:31 +01:00
Peter Maydell 84f3fe1b07 trace: Fix build warnings for Win32 build
The Win32 build warns about trace/control-internal.h:

warning: 'trace_event_count' declared inline after being called

Fix this by simply reordering trace_event_id() and
trace_event_count().

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Stefan Weil <sw@weilnetz.de>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2014-03-12 14:19:58 +01:00
Mohamad Gebai e6bf23f82d Adapt Makefiles to the new LTTng ust interface
Add generation of new files for LTTng ust.

Signed-off-by: Mohamad Gebai <mohamad.gebai@polymtl.ca>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2014-02-19 11:08:53 +01:00
Stefan Hajnoczi 05735a2a9c trace: add glib 2.32+ static GMutex support
The GStaticMutex API was deprecated in glib 2.32.  We cannot switch over
to GMutex unconditionally since we would drop support for older glib
versions.  But the deprecated API warnings during build are annoying so
use static GMutex when possible.

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2014-01-27 15:49:39 +01:00
Lluís Vilanova b618c28831 trace: [simple] Do not include "trace/simple.h" in generated tracer headers
The header is not necessary, given that the simple backend does not define any
inlined tracing routines.

Signed-off-by: Lluís Vilanova <vilanova@ac.upc.edu>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2014-01-27 15:49:39 +01:00
Eiichi Tsukata 781e9545db trace: Add ftrace tracing backend
This patch adds a ftrace tracing backend which sends trace event to
ftrace marker file. You can effectively compare qemu trace data and
kernel(especially, kvm.ko when using KVM) trace data.
The ftrace backend is restricted to Linux only.

To try out the ftrace backend:

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

if you use KVM, enable kvm events in ftrace:

 # sudo echo 1 > /sys/kernel/debug/tracing/events/kvm/enable

After running qemu by root user, you can get the trace:

 # cat /sys/kernel/debug/tracing/trace

Signed-off-by: Eiichi Tsukata <eiichi.tsukata.xh@hitachi.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2013-05-03 13:58:09 +02:00
Stefan Hajnoczi a7373b1f61 trace: rebuild generated-events.o when configuration changes
Make sure to rebuild generated-events.o when ./configure options change.
This prevents linker errors when a stale generated-events.o gets linked
with code compiled against fresh headers.  For example, try building
with ./configure --enable-trace-backend=stderr followed by ./configure
--enable-trace-backend=dtrace.

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2013-03-28 14:19:57 +01:00
Lluís Vilanova c6f18b9195 trace: [stderr] Port to generic event information and new control interface
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
Lluís Vilanova 60481e210d trace: [simple] Port to generic event information and new control interface
The backend is forced to dump event numbers using 64 bits, as TraceEventID is
an enum.

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
Lluís Vilanova fd068a953c trace: [default] Port to generic event information and new control interface
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
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
Lluís Vilanova 45be2f5d0d trace: Provide a generic tracing event descriptor
Uses tracetool to generate a backend-independent tracing event description
(struct TraceEvent).

The values for such structure are generated with the non-public "events"
backend ("events-c" frontend).

The generation of the defines to check if an event is statically enabled is also
moved to the "events" backend ("events-h" frontend).

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
Stefan Hajnoczi 4a0e6714b0 trace: deal with deprecated glib thread functions
g_thread_create() was deprecated in favor of g_thread_new() and
g_cond_new() was deprecated in favor of GCond initialization.  If the
host has glib 2.31 or newer, avoid using the deprecated functions.

This patch solves compiler warnings that are generated when glib's
deprecated functions are used.

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-id: 1360676045-9204-3-git-send-email-stefanha@redhat.com
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2013-02-12 16:26:44 -06:00
Stefan Hajnoczi 30d940875d trace: use glib atomic int types
Juan reported that RHEL 6.4 hosts give compiler warnings because we use
unsigned int while glib prototypes use volatile gint in trace/simple.c.

  trace/simple.c:223: error: pointer targets in passing argument 1 of 'g_atomic_int_compare_and_exchange' differ in signedness

These variables are only accessed with glib atomic int functions so
let's play it by the book and use volatile gint.

Reported-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-id: 1360676045-9204-2-git-send-email-stefanha@redhat.com
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2013-02-12 16:26:43 -06:00
Markus Armbruster b6b2c96280 trace: Clean up the "try to update atomic until it worked" loops
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Laszlo Ersek <lersek@redhat.com>
Reviewed-by: Harsh Prateek Bora <harsh@linux.vnet.ibm.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2013-02-05 21:52:55 +01:00
Markus Armbruster e722d705ae trace: Direct access of atomics is verboten, use the API
The GLib Reference Manual says:

    It is very important that all accesses to a particular integer or
    pointer be performed using only this API and that different sizes
    of operation are not mixed or used on overlapping memory
    regions. Never read or assign directly from or to a value --
    always use this API.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Laszlo Ersek <lersek@redhat.com>
Reviewed-by: Harsh Prateek Bora <harsh@linux.vnet.ibm.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2013-02-05 21:52:55 +01:00
Markus Armbruster fb3a508531 trace: Fix simple trace dropped event record for big endian
We use atomic operations to keep track of dropped events.

Inconveniently, GLib supports only int and void * atomics, but the
counter dropped_events is uint64_t.  Can't stop commit 62bab732: a
quick (gint *)&dropped_events bludgeons the compiler into submission.

That cast is okay only when int is exactly 64 bits wide, which it
commonly isn't.

If int is even wider, we clobber whatever follows dropped_events.  Not
worth worrying about, as none of the machines that interest us have
such morbidly obese ints.

That leaves the common case: int narrower than 64 bits.

Harmless on little endian hosts: we just don't access the most
significant bits of dropped_events.  They remain zero.

On big endian hosts, we use only the most significant bits of
dropped_events as counter.  The least significant bits remain zero.
However, we write out the full value, which is the correct counter
shifted left a bunch of places.

Fix by changing the variables involved to int.

There's another, equally suspicious-looking (gint *)&trace_idx
argument to g_atomic_int_compare_and_exchange(), but that one casts
unsigned *, so it's okay.  But it's also superfluous, because GLib's
atomic int operations work just fine for unsigned.  Drop it.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Laszlo Ersek <lersek@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2013-02-05 21:52:55 +01:00
Michael S. Tsirkin 6f329a5530 Makefile: clean timestamp generation rule
create timestamp by rule without sideeffects.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2013-01-30 01:31:08 +02:00
Paolo Bonzini ff667e2e9b build: fold trace-obj-y into libqemuutil.a
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2013-01-12 18:42:51 +01:00
Paolo Bonzini 0e848f482b build: some simplifications for "trace/Makefile.objs"
Signed-off-by: Lluís Vilanova <vilanova@ac.upc.edu>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2013-01-12 18:42:51 +01:00
Paolo Bonzini 2c13ec50e7 build: move dtrace rules to rules.mak
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2013-01-12 17:19:09 +01:00
Lluís Vilanova eac236ea7b build: Use separate makefile for "trace/"
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Lluís Vilanova <vilanova@ac.upc.edu>
--
Changes in v2:

* Do not depend on "qemu-timer-common.o".
* Use "$(obj)" in rules to refer to the build sub-directory.
* Remove dependencies against "$(GENERATED_HEADERS)".

Cc: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2012-12-23 14:28:02 -06:00
Paolo Bonzini 1de7afc984 misc: move include files to include/qemu/
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2012-12-19 08:32:39 +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
Stefan Weil 4552e41025 trace/simple: Replace asprintf by g_strdup_printf
asprintf is not available for all hosts. g_strdup_printf is
more portable and simplifies the code because if does not
need error handling.

The static variable does not need an explicit assignment to be NULL.

Cc: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Signed-off-by: Stefan Weil <sw@weilnetz.de>
Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
2012-08-14 13:19:57 +01:00
Harsh Prateek Bora db8894f209 trace: avoid pointer aliasing in trace_record_finish()
Declaring a TraceRecord on the stack works fine.  No need for a
uint8_t array and pointer aliasing.

Signed-off-by: Harsh Prateek Bora <harsh@linux.vnet.ibm.com>
Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
2012-08-14 10:40:39 +01:00
Harsh Prateek Bora fd82f015a1 trace: drop unused TraceBufferRecord->next_tbuf_idx field
Signed-off-by: Harsh Prateek Bora <harsh@linux.vnet.ibm.com>
Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
2012-08-14 10:40:39 +01:00
Harsh Prateek Bora 83d35d3e99 trace: remove unnecessary write_to_buffer() typecasting
The buffer argument is void* so it is not necessary to cast.

Signed-off-by: Harsh Prateek Bora <harsh@linux.vnet.ibm.com>
Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
2012-08-14 10:40:39 +01:00
Harsh Prateek Bora 8ae601e8fe trace: rename TraceRecordHeader to TraceLogHeader
The TraceRecordHeader is really the header for the entire trace log
file.  It's not per-record header so make this obvious by renaming it.

Signed-off-by: Harsh Prateek Bora <harsh@linux.vnet.ibm.com>
Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
2012-08-14 10:40:39 +01:00
Harsh Prateek Bora 62bab73213 Simpletrace v2: Support multiple arguments, strings.
Existing simpletrace backend allows to trace at max 6 args and does not
support strings. This newer tracelog format gets rid of fixed size records
and therefore allows to trace variable number of args including strings.

Sample trace with strings:
v9fs_version 0.000 tag=0xffff id=0x64 msize=0x2000 version=9P2000.L
v9fs_version_return 6.705 tag=0xffff id=0x64 msize=0x2000 version=9P2000.L

Signed-off-by: Harsh Prateek Bora <harsh@linux.vnet.ibm.com>
Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
2012-07-19 11:34:33 +01:00
Harsh Prateek Bora 88affa1c77 monitor: remove unused do_info_trace
Going forward with simpletrace v2 variable size trace records, we cannot
have a generic function to print trace event info and therefore this
interface becomes invalid.

As per Stefan Hajnoczi:

"This command is only available from the human monitor.  It's not very
useful because it historically hasn't been able to pretty-print events
or show them in the right order (we use a ringbuffer but it prints
them out from index 0).

Therefore, I don't think we're under any obligation to keep this
command around.  No one has complained about it's limitations - I
think this is a sign that no one has used it.  I'd be okay with a
patch that removes it."

Ref: http://lists.gnu.org/archive/html/qemu-devel/2012-01/msg01268.html

Signed-off-by: Harsh Prateek Bora <harsh@linux.vnet.ibm.com>
Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
2012-07-19 11:34:32 +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