st_set_trace_file() accidentally enables tracing. It's called
unconditionally during startup, which is why QEMU built with the
simple trace backend always writes a trace file "trace-$PID".
This has been broken for quite a while. I didn't track down the exact
commit.
Fix st_set_trace_file() to restore the state.
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-id: 20200527065613.25322-1-armbru@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
st_print_trace_file_status() takes an fprintf()-like callback and a
FILE * to pass to it.
Its only caller hmp_trace_file() passes monitor_fprintf() and the
current monitor cast to FILE *. monitor_fprintf() casts it right
back, and is otherwise identical to monitor_printf(). The
type-punning is ugly.
Drop the callback, and call qemu_printf() instead.
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Message-Id: <20190417191805.28198-3-armbru@redhat.com>
Per supported platforms doc[1], the various min glib on relevant distros is:
RHEL-7: 2.50.3
Debian (Stretch): 2.50.3
Debian (Jessie): 2.42.1
OpenBSD (Ports): 2.54.3
FreeBSD (Ports): 2.50.3
OpenSUSE Leap 15: 2.54.3
SLE12-SP2: 2.48.2
Ubuntu (Xenial): 2.48.0
macOS (Homebrew): 2.56.0
This suggests that a minimum glib of 2.42 is a reasonable target.
The GLibC compile farm, however, uses Ubuntu 14.04 (Trusty) which only
has glib 2.40.0, and this is needed for testing during merge. Thus an
exception is made to the documented platform support policy to allow for
all three current LTS releases to be supported.
Docker jobs that not longer satisfy this new min version are removed.
[1] https://qemu.weilnetz.de/doc/qemu-doc.html#Supported-build-platforms
Reviewed-by: Thomas Huth <thuth@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
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>
Currently simpletrace assumes that events are given IDs
starting from 0, based on the order in which they appear
in the trace-events file, with no gaps. When the
trace-events file is split up, this assumption becomes
problematic.
To deal with this, extend the simpletrace format so that
it outputs a table of event name <-> ID mappings. That
will allow QEMU to assign arbitrary IDs to events without
breaking simpletrace parsing.
The v3 simple trace format was
FILE HEADER
EVENT TRACE RECORD 0
EVENT TRACE RECORD 1
...
EVENT TRACE RECORD N
The v4 simple trace format is now
FILE HEADER
EVENT MAPPING RECORD 0
EVENT MAPPING RECORD 1
...
EVENT MAPPING RECORD M
EVENT TRACE RECORD RECORD 0
EVENT TRACE RECORD RECORD 1
...
EVENT TRACE RECORD N
Although this shows all the mapping records being emitted
upfront, this is not required by the format. While the main
simpletrace backend will emit all mappings at startup,
the systemtap simpletrace.stp script will emit the mappings
at first use. eg
FILE HEADER
...
EVENT MAPPING RECORD 0
EVENT TRACE RECORD RECORD 0
EVENT TRACE RECORD RECORD 1
EVENT MAPPING RECORD 1
EVENT TRACE RECORD RECORD 2
...
EVENT TRACE RECORD N
This is more space efficient given that most trace records
only include a subset of events.
In modifying the systemtap simpletrace code, a 'begin' probe
was added to emit the trace event header, so you no longer
need to add '--no-header' when running simpletrace.py for
systemtap generated trace files.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Message-id: 1475588159-30598-12-git-send-email-berrange@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
