These patches were previously posted as part of my giant trace events modular build series
v1: https://lists.gnu.org/archive/html/qemu-devel/2016-08/msg01714.html v2: https://lists.gnu.org/archive/html/qemu-devel/2016-09/msg03335.html This series does all the refactoring required to support a fully modular build of the trace probe points, but does not actually convert anything to use it. The 40+ patches to convert each subdir to use modular build will only be posted again, once the refactoring is reviewed & queued, in order to avoid patch-bombing the list more than is needed. The full series is visible at https://github.com/berrange/qemu/tree/trace-events-3 The key problem being tackled by this series is the assumption that there is a single statically declared enum which provides globally unique event IDs. Inside QEMU the event IDs were used as list indexes into the 'trace_events' array, while the event VCPU IDs were used as bitmap indexes in trace_dstate against the CPUState struct. Externally to QEMU, the event IDs were also written in the simpletrace binary data format and used to lookup the entry in the trace-events file afterwards. Inside QEMU the refactoring work managed to remove all need for event IDs for purposes of 'trace_events' array lookups. Instead we now have global variables per-event which can be referenced directly. When QEMU starts up and the various event groups are registered, we now dynamically assign event IDs and VCPU IDs to each event. This removes the limitation in the v1 posting that all vCPU events had to be in one file. We also removed the limitation on the total number of vCPU events. So there is no regression in functionality of VCPU event support compared to current GIT master. Since the event IDs are allocated dynamically at runtime, the simpletrace.py script cannot assume they map directly to the 'trace-events' file entries. Thus, the simpletrace binary format is extended to include a record type that maps trace event IDs to trace event names. While it would be possible to take this even further and make the simpletrace binary format 100% self-describing this is left as an exercise for future developers, as it is not a pre-requisite for this modular build. While some of the intermediate patches may seem pointless on their own, they exist in order to facilitate the review of later patches by ensuring each patch does the minimum possible refactoring work. Changed in v4: - Misc typos / indentation (Lluís, Eric) - Simplify do_trace_enable_events (Lluís) - Use Event.api() in more places (Lluís) - Actually delete events_{h,c}.py (Lluís) - Use bitmap_new() for allocation (Lluís) - Dont use .git to make relative path (Lluís) Changed in v3: - Change simpletrace format to write a mapping of IDs to names - Declare a TraceEvent variable per event, instead of just an array - Make 'trace_events' array be 'TraceEvent **' instead of 'TraceEvent *' - Fix infinite loop in iterators due to bad fix in v2 posting. - Dynamically allocate the trace_dstate variable in CPUState based on actual number of vcpu events registered at runtime - Push logic for determining group name into the tracetool program - Fix to ftrace to make it more practical for users who sometimes run QEMU as non-root. - Get rid of TraceEventID/VCPUID enums entirely Changed in v2: - Fixed filtering of events on first call of iterator_next (Stefan) - Switch from size_t to uint32_t for event ID type (Paolo/Stefan) - Replace global 'dstate' array with individual variables (Lluís) Daniel P. Berrange (17): trace: add trace event iterator APIs trace: convert code to use event iterators trace: remove some now unused functions trace: remove global 'uint16 dstate[]' array trace: remove duplicate control.h includes in generated-tracers.h trace: break circular dependency in event-internal.h trace: give each trace event a named TraceEvent struct trace: remove the TraceEventID and TraceEventVCPUID enums trace: emit name <-> ID mapping in simpletrace header trace: don't abort qemu if ftrace can't be initialized trace: provide mechanism for registering trace events trace: dynamically allocate trace_dstate in CPUState trace: dynamically allocate event IDs at runtime trace: get rid of generated-events.h/generated-events.c trace: rename _read_events to read_events trace: push reading of events up a level to tracetool main trace: pass trace-events to tracetool as a positional param Makefile | 3 - Makefile.target | 6 +- include/qemu/module.h | 2 + include/qom/cpu.h | 8 +- include/trace-tcg.h | 1 - include/trace.h | 1 - monitor.c | 26 +++--- qemu-img.c | 1 + qemu-io.c | 1 + qemu-nbd.c | 1 + qom/cpu.c | 6 +- scripts/simpletrace.py | 56 +++++++---- scripts/tracetool.py | 7 +- scripts/tracetool/__init__.py | 24 +++-- scripts/tracetool/backend/ftrace.py | 1 - scripts/tracetool/backend/log.py | 3 +- scripts/tracetool/backend/simple.py | 4 +- scripts/tracetool/backend/syslog.py | 1 - scripts/tracetool/format/c.py | 50 +++++++++- scripts/tracetool/format/events_c.py | 44 --------- scripts/tracetool/format/events_h.py | 60 ------------ scripts/tracetool/format/h.py | 23 ++++- scripts/tracetool/format/simpletrace_stap.py | 24 ++++- stubs/trace-control.c | 9 +- trace/Makefile.objs | 46 +++------ trace/control-internal.h | 48 ++++------ trace/control-target.c | 22 ++--- trace/control.c | 134 +++++++++++++++++---------- trace/control.h | 111 +++++++--------------- trace/event-internal.h | 18 +++- trace/ftrace.c | 6 ++ trace/qmp.c | 16 ++-- trace/simple.c | 41 ++++++-- trace/simple.h | 6 +- vl.c | 2 + 35 files changed, 417 insertions(+), 395 deletions(-) delete mode 100644 scripts/tracetool/format/events_c.py delete mode 100644 scripts/tracetool/format/events_h.py -- 2.7.4
