On 06/17, Oleg Nesterov wrote:
>
> DECLARE_EVENT_CLASS()->perf_trace_##call() is not trivial because
> of __perf_task()
Perhaps we can do something like below?
Then we can
1. kill __perf_addr(), __perf_count(), __perf_task() and
TP_perf_assign()
2. Add the fast path check
if (builtin_constant(__task) && !__task &&
hlist_empty(head)))
return;
into perf_trace_call() right after ftrace_get_offsets_call().
Doesn't look very nice, it relies on the fact that
ftrace_get_offsets_call(args) evaluates TP_perf_arg()'s hidden in
TP_ARGS().
OTOH, the whole point of include/trace/ is to create the code which
nobody except the maintainers can understand. At least I certainly
can't ;) So perhaps this is fine.
Oleg.
--- a/include/trace/events/sched.h
+++ b/include/trace/events/sched.h
@@ -57,7 +57,7 @@ DECLARE_EVENT_CLASS(sched_wakeup_template,
TP_PROTO(struct task_struct *p, int success),
- TP_ARGS(p, success),
+ TP_ARGS(TP_perf_arg(__task, p), success),
TP_STRUCT__entry(
__array( char, comm, TASK_COMM_LEN )
@@ -73,9 +73,6 @@ DECLARE_EVENT_CLASS(sched_wakeup_template,
__entry->prio = p->prio;
__entry->success = success;
__entry->target_cpu = task_cpu(p);
- )
- TP_perf_assign(
- __perf_task(p);
),
TP_printk("comm=%s pid=%d prio=%d success=%d target_cpu=%03d",
@@ -313,7 +310,7 @@ DECLARE_EVENT_CLASS(sched_stat_template,
TP_PROTO(struct task_struct *tsk, u64 delay),
- TP_ARGS(tsk, delay),
+ TP_ARGS(TP_perf_arg(__task, tsk), TP_perf_arg(__count, delay)),
TP_STRUCT__entry(
__array( char, comm, TASK_COMM_LEN )
@@ -325,10 +322,6 @@ DECLARE_EVENT_CLASS(sched_stat_template,
memcpy(__entry->comm, tsk->comm, TASK_COMM_LEN);
__entry->pid = tsk->pid;
__entry->delay = delay;
- )
- TP_perf_assign(
- __perf_count(delay);
- __perf_task(tsk);
),
TP_printk("comm=%s pid=%d delay=%Lu [ns]",
--- a/include/trace/ftrace.h
+++ b/include/trace/ftrace.h
@@ -506,6 +506,9 @@ static inline notrace int ftrace_get_offsets_##call(
\
#undef TP_perf_assign
#define TP_perf_assign(args...)
+#undef TP_perf_arg
+#define TP_perf_arg(var, val) (val)
+
#undef DECLARE_EVENT_CLASS
#define DECLARE_EVENT_CLASS(call, proto, args, tstruct, assign, print) \
\
@@ -643,6 +646,9 @@ __attribute__((section("_ftrace_events"))) *__event_##call
= &event_##call
#undef TP_perf_assign
#define TP_perf_assign(args...) args
+#undef TP_perf_arg
+#define TP_perf_arg(var, val) (var = (val))
+
#undef DECLARE_EVENT_CLASS
#define DECLARE_EVENT_CLASS(call, proto, args, tstruct, assign, print) \
static notrace void \
@@ -659,13 +665,12 @@ perf_trace_##call(void *__data, proto)
\
int __data_size; \
int rctx; \
\
- perf_fetch_caller_regs(&__regs); \
- \
__data_size = ftrace_get_offsets_##call(&__data_offsets, args); \
__entry_size = ALIGN(__data_size + sizeof(*entry) + sizeof(u32),\
sizeof(u64)); \
__entry_size -= sizeof(u32); \
\
+ perf_fetch_caller_regs(&__regs); \
entry = (struct ftrace_raw_##call *)perf_trace_buf_prepare( \
__entry_size, event_call->event.type, &__regs, &rctx); \
if (!entry) \
--
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