Daniel P Berrange writes:
> 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.
> Signed-off-by: Daniel P. Berrange <berra...@redhat.com>
Disregarding comment below:
Reviewed-by: Lluís Vilanova <vilan...@ac.upc.edu>
> ---
> scripts/tracetool/backend/simple.py | 4 ++--
> scripts/tracetool/format/events_c.py | 16 +++++++++++-----
> scripts/tracetool/format/events_h.py | 18 +++---------------
> scripts/tracetool/format/h.py | 3 +--
> trace/control-internal.h | 19 ++++++++++---------
> trace/control-target.c | 2 +-
> trace/control.c | 2 +-
> trace/control.h | 31 ++++++++-----------------------
> trace/event-internal.h | 6 ++++++
> trace/simple.c | 8 ++++----
> trace/simple.h | 2 +-
> 11 files changed, 48 insertions(+), 63 deletions(-)
> diff --git a/scripts/tracetool/backend/simple.py
> b/scripts/tracetool/backend/simple.py
> index 1bccada..1114e35 100644
> --- a/scripts/tracetool/backend/simple.py
> +++ b/scripts/tracetool/backend/simple.py
> @@ -80,11 +80,11 @@ def generate_c(event):
> ' return;',
> ' }',
> '',
> - ' if (trace_record_start(&rec, %(event_id)s, %(size_str)s)) {',
> + ' if (trace_record_start(&rec, %(event_obj)s.id, %(size_str)s))
> {',
> ' return; /* Trace Buffer Full, Event Dropped ! */',
> ' }',
> cond=cond,
> - event_id=event_id,
> + event_obj=event.api(event.QEMU_EVENT),
> size_str=sizestr)
> if len(event.args) > 0:
> diff --git a/scripts/tracetool/format/events_c.py
> b/scripts/tracetool/format/events_c.py
> index 0dd4a33..325f4e0 100644
> --- a/scripts/tracetool/format/events_c.py
> +++ b/scripts/tracetool/format/events_c.py
> @@ -28,11 +28,16 @@ def generate(events, backend):
> for e in events:
> out('uint16_t %s;' % e.api(e.QEMU_DSTATE))
> + next_id = 0
> + next_vcpu_id = 0
> for e in events:
> + id = next_id
> + next_id += 1
> if "vcpu" in e.properties:
> - vcpu_id = "TRACE_VCPU_" + e.name.upper()
> + vcpu_id = next_vcpu_id
> + next_vcpu_id += 1
> else:
> - vcpu_id = "TRACE_VCPU_EVENT_COUNT"
> + vcpu_id = "TRACE_VCPU_EVENT_NONE"
> out('TraceEvent %(event)s = {',
> ' .id = %(id)s,',
> ' .vcpu_id = %(vcpu_id)s,',
> @@ -41,16 +46,17 @@ def generate(events, backend):
> ' .dstate = &%(dstate)s ',
> '};',
> event = e.api(e.QEMU_EVENT),
> - id = "TRACE_" + e.name.upper(),
> + id = id,
> vcpu_id = vcpu_id,
> name = e.name,
> sstate = "TRACE_%s_ENABLED" % e.name.upper(),
> dstate = e.api(e.QEMU_DSTATE))
> - out('TraceEvent *trace_events[TRACE_EVENT_COUNT] = {')
> + out('TraceEvent *trace_events[] = {')
> for e in events:
> out('&%(event)s,', event = e.api(e.QEMU_EVENT))
> - out('};',
> + out(' NULL,',
> + '};',
> '')
> diff --git a/scripts/tracetool/format/events_h.py
> b/scripts/tracetool/format/events_h.py
> index 80a66c5..5da1d4c 100644
> --- a/scripts/tracetool/format/events_h.py
> +++ b/scripts/tracetool/format/events_h.py
> @@ -29,27 +29,15 @@ def generate(events, backend):
> out('extern TraceEvent %(event)s;',
> event = e.api(e.QEMU_EVENT))
> - # event identifiers
> - out('typedef enum {')
> -
> - for e in events:
> - out(' TRACE_%s,' % e.name.upper())
> -
> - out(' TRACE_EVENT_COUNT',
> - '} TraceEventID;')
> -
> for e in events:
> out('extern uint16_t %s;' % e.api(e.QEMU_DSTATE))
> - # per-vCPU event identifiers
> - out('typedef enum {')
> -
> + numvcpu = 0
> for e in events:
> if "vcpu" in e.properties:
> - out(' TRACE_VCPU_%s,' % e.name.upper())
> + numvcpu += 1
> - out(' TRACE_VCPU_EVENT_COUNT',
> - '} TraceEventVCPUID;')
Here's a more pythonic way to write it:
numvcpu = len([e for e in events if "vcpu" in e.properties])
> + out("#define TRACE_VCPU_EVENT_COUNT %d" % numvcpu)
> # static state
> for e in events:
> diff --git a/scripts/tracetool/format/h.py b/scripts/tracetool/format/h.py
> index 3763e9a..64a6680 100644
> --- a/scripts/tracetool/format/h.py
> +++ b/scripts/tracetool/format/h.py
> @@ -32,8 +32,7 @@ def generate(events, backend):
> if "vcpu" in e.properties:
> trace_cpu = next(iter(e.args))[1]
> cond = "trace_event_get_vcpu_state(%(cpu)s,"\
> - " TRACE_%(id)s,"\
> - " TRACE_VCPU_%(id)s)"\
> + " TRACE_%(id)s)"\
> % dict(
> cpu=trace_cpu,
> id=e.name.upper())
> diff --git a/trace/control-internal.h b/trace/control-internal.h
> index 52b6b72..8bfbdfb 100644
> --- a/trace/control-internal.h
> +++ b/trace/control-internal.h
> @@ -25,20 +25,20 @@ static inline bool trace_event_is_pattern(const char *str)
> return strchr(str, '*') != NULL;
> }
> -static inline TraceEventID trace_event_get_id(TraceEvent *ev)
> +static inline uint32_t trace_event_get_id(TraceEvent *ev)
> {
> assert(ev != NULL);
> return ev->id;
> }
> -static inline TraceEventVCPUID trace_event_get_vcpu_id(TraceEvent *ev)
> +static inline uint32_t trace_event_get_vcpu_id(TraceEvent *ev)
> {
> return ev->vcpu_id;
> }
> static inline bool trace_event_is_vcpu(TraceEvent *ev)
> {
> - return ev->vcpu_id != TRACE_VCPU_EVENT_COUNT;
> + return ev->vcpu_id != TRACE_VCPU_EVENT_NONE;
> }
> static inline const char * trace_event_get_name(TraceEvent *ev)
> @@ -62,12 +62,13 @@ static inline bool
> trace_event_get_state_dynamic(TraceEvent *ev)
> return unlikely(trace_events_enabled_count) && *ev->dstate;
> }
> -static inline bool trace_event_get_vcpu_state_dynamic_by_vcpu_id(CPUState
> *vcpu,
> -
> TraceEventVCPUID id)
> +static inline bool
> +trace_event_get_vcpu_state_dynamic_by_vcpu_id(CPUState *vcpu,
> + uint32_t vcpu_id)
> {
> /* it's on fast path, avoid consistency checks (asserts) */
> if (unlikely(trace_events_enabled_count)) {
> - return test_bit(id, vcpu->trace_dstate);
> + return test_bit(vcpu_id, vcpu->trace_dstate);
> } else {
> return false;
> }
> @@ -76,10 +77,10 @@ static inline bool
> trace_event_get_vcpu_state_dynamic_by_vcpu_id(CPUState *vcpu,
> static inline bool trace_event_get_vcpu_state_dynamic(CPUState *vcpu,
> TraceEvent *ev)
> {
> - TraceEventVCPUID id;
> + uint32_t vcpu_id;
> assert(trace_event_is_vcpu(ev));
> - id = trace_event_get_vcpu_id(ev);
> - return trace_event_get_vcpu_state_dynamic_by_vcpu_id(vcpu, id);
> + vcpu_id = trace_event_get_vcpu_id(ev);
> + return trace_event_get_vcpu_state_dynamic_by_vcpu_id(vcpu, vcpu_id);
> }
> #endif /* TRACE__CONTROL_INTERNAL_H */
> diff --git a/trace/control-target.c b/trace/control-target.c
> index c69dda9..ff1bf43 100644
> --- a/trace/control-target.c
> +++ b/trace/control-target.c
> @@ -59,7 +59,7 @@ void trace_event_set_state_dynamic(TraceEvent *ev, bool
> state)
> void trace_event_set_vcpu_state_dynamic(CPUState *vcpu,
> TraceEvent *ev, bool state)
> {
> - TraceEventVCPUID vcpu_id;
> + uint32_t vcpu_id;
> bool state_pre;
> assert(trace_event_get_state_static(ev));
> assert(trace_event_is_vcpu(ev));
> diff --git a/trace/control.c b/trace/control.c
> index 9107919..64aaede 100644
> --- a/trace/control.c
> +++ b/trace/control.c
> @@ -105,7 +105,7 @@ void trace_event_iter_init(TraceEventIter *iter, const
> char *pattern)
> TraceEvent *trace_event_iter_next(TraceEventIter *iter)
> {
> - while (iter->event < TRACE_EVENT_COUNT) {
> + while (trace_events[iter->event] != NULL) {
> TraceEvent *ev = trace_events[iter->event];
iter-> event++;
> if (!iter->pattern ||
> diff --git a/trace/control.h b/trace/control.h
> index e80c220..21ce5f1 100644
> --- a/trace/control.h
> +++ b/trace/control.h
> @@ -18,17 +18,6 @@ typedef struct TraceEventIter {
> const char *pattern;
> } TraceEventIter;
> -/**
> - * TraceEventID:
> - *
> - * Unique tracing event identifier.
> - *
> - * These are named as 'TRACE_${EVENT_NAME}'.
> - *
> - * See also: "trace/generated-events.h"
> - */
> -enum TraceEventID;
> -
> /**
> * trace_event_iter_init:
> @@ -76,17 +65,17 @@ static bool trace_event_is_pattern(const char *str);
> *
> * Get the identifier of an event.
> */
> -static TraceEventID trace_event_get_id(TraceEvent *ev);
> +static uint32_t trace_event_get_id(TraceEvent *ev);
> /**
> * trace_event_get_vcpu_id:
> *
> * Get the per-vCPU identifier of an event.
> *
> - * Special value #TRACE_VCPU_EVENT_COUNT means the event is not vCPU-specific
> + * Special value #TRACE_VCPU_EVENT_NONE means the event is not vCPU-specific
> * (does not have the "vcpu" property).
> */
> -static TraceEventVCPUID trace_event_get_vcpu_id(TraceEvent *ev);
> +static uint32_t trace_event_get_vcpu_id(TraceEvent *ev);
> /**
> * trace_event_is_vcpu:
> @@ -104,14 +93,12 @@ static const char * trace_event_get_name(TraceEvent *ev);
> /**
> * trace_event_get_state:
> - * @id: Event identifier.
> + * @id: Event identifier name.
> *
> * Get the tracing state of an event (both static and dynamic).
> *
> * If the event has the disabled property, the check will have no performance
> * impact.
> - *
> - * As a down side, you must always use an immediate #TraceEventID value.
> */
> #define trace_event_get_state(id) \
> ((id ##_ENABLED) && trace_event_get_state_dynamic_by_id(id))
> @@ -119,19 +106,17 @@ static const char * trace_event_get_name(TraceEvent
> *ev);
> /**
> * trace_event_get_vcpu_state:
> * @vcpu: Target vCPU.
> - * @id: Event identifier (TraceEventID).
> - * @vcpu_id: Per-vCPU event identifier (TraceEventVCPUID).
> + * @id: Event identifier name.
> *
> * Get the tracing state of an event (both static and dynamic) for the given
> * vCPU.
> *
> * If the event has the disabled property, the check will have no performance
> * impact.
> - *
> - * As a down side, you must always use an immediate #TraceEventID value.
> */
> -#define trace_event_get_vcpu_state(vcpu, id, vcpu_id) \
> - ((id ##_ENABLED) && trace_event_get_vcpu_state_dynamic_by_vcpu_id(vcpu,
> vcpu_id))
> +#define trace_event_get_vcpu_state(vcpu, id) \
> + ((id ##_ENABLED) && \
> + trace_event_get_vcpu_state_dynamic_by_vcpu_id(vcpu, id ##
> _EVENT.vcpu_id))
> /**
> * trace_event_get_state_static:
> diff --git a/trace/event-internal.h b/trace/event-internal.h
> index 58f0551..f63500b 100644
> --- a/trace/event-internal.h
> +++ b/trace/event-internal.h
> @@ -10,6 +10,12 @@
> #ifndef TRACE__EVENT_INTERNAL_H
> #define TRACE__EVENT_INTERNAL_H
> +/*
> + * Special value for TraceEvent.vcpu_id field to indicate
> + * that the event is not VCPU specific
> + */
> +#define TRACE_VCPU_EVENT_NONE ((uint32_t)-1)
> +
> /**
> * TraceEvent:
> * @id: Unique event identifier.
> diff --git a/trace/simple.c b/trace/simple.c
> index 2f09daf..2ec32e1 100644
> --- a/trace/simple.c
> +++ b/trace/simple.c
> @@ -17,8 +17,8 @@
> #include "trace/control.h"
> #include "trace/simple.h"
> -/** Trace file header event ID */
> -#define HEADER_EVENT_ID (~(uint64_t)0) /* avoids conflicting with
> TraceEventIDs */
> +/** Trace file header event ID, picked to avoid conflict with real event IDs
> */
> +#define HEADER_EVENT_ID (~(uint64_t)0)
> /** Trace file magic number */
> #define HEADER_MAGIC 0xf2b177cb0aa429b4ULL
> @@ -58,7 +58,7 @@ static char *trace_file_name;
> /* * Trace buffer entry */
> typedef struct {
> - uint64_t event; /* TraceEventID */
> + uint64_t event; /* event ID value */
> uint64_t timestamp_ns;
> uint32_t length; /* in bytes */
> uint32_t pid;
> @@ -202,7 +202,7 @@ void trace_record_write_str(TraceBufferRecord *rec, const
> char *s, uint32_t slen
rec-> rec_off = write_to_buffer(rec->rec_off, (void*)s, slen);
> }
> -int trace_record_start(TraceBufferRecord *rec, TraceEventID event, size_t
> datasize)
> +int trace_record_start(TraceBufferRecord *rec, uint32_t event, size_t
> datasize)
> {
> unsigned int idx, rec_off, old_idx, new_idx;
> uint32_t rec_len = sizeof(TraceRecord) + datasize;
> diff --git a/trace/simple.h b/trace/simple.h
> index 1e7de45..17ce472 100644
> --- a/trace/simple.h
> +++ b/trace/simple.h
> @@ -33,7 +33,7 @@ typedef struct {
> *
> * @arglen number of bytes required for arguments
> */
> -int trace_record_start(TraceBufferRecord *rec, TraceEventID id, size_t
> arglen);
> +int trace_record_start(TraceBufferRecord *rec, uint32_t id, size_t arglen);
> /**
> * Append a 64-bit argument to a trace record
> --
> 2.7.4
Thanks,
Lluis
