Re: [PATCH 1/1] tracing, workqueuetrace: Make workqueuetracepoints use TRACE_EVENT macro
From: Frederic Weisbecker
Date: Mon Apr 13 2009 - 10:13:58 EST
On Mon, Apr 13, 2009 at 08:54:35AM +0800, Zhaolei wrote:
> TRACE_EVENT is a more generic way to define tracepoints.
> Doing so adds these new capabilities to this tracepoint:
>
> - zero-copy and per-cpu splice() tracing
> - binary tracing without printf overhead
> - structured logging records exposed under /debug/tracing/events
> - trace events embedded in function tracer output and other plugins
> - user-defined, per tracepoint filter expressions
>
> Signed-off-by: Zhao Lei <zhaolei@xxxxxxxxxxxxxx>
> ---
> include/trace/trace_event_types.h | 1 +
> include/trace/trace_events.h | 1 +
> include/trace/workqueue.h | 19 +------
> include/trace/workqueue_event_types.h | 101 +++++++++++++++++++++++++++++++++
> 4 files changed, 105 insertions(+), 17 deletions(-)
> create mode 100644 include/trace/workqueue_event_types.h
>
> diff --git a/include/trace/trace_event_types.h b/include/trace/trace_event_types.h
> index 552a50e..2babba4 100644
> --- a/include/trace/trace_event_types.h
> +++ b/include/trace/trace_event_types.h
> @@ -5,3 +5,4 @@
> #include <trace/lockdep_event_types.h>
> #include <trace/skb_event_types.h>
> #include <trace/kmem_event_types.h>
> +#include <trace/workqueue_event_types.h>
> diff --git a/include/trace/trace_events.h b/include/trace/trace_events.h
> index 13d6b85..2e0f58c 100644
> --- a/include/trace/trace_events.h
> +++ b/include/trace/trace_events.h
> @@ -5,3 +5,4 @@
> #include <trace/lockdep.h>
> #include <trace/skb.h>
> #include <trace/kmem.h>
> +#include <trace/workqueue.h>
> diff --git a/include/trace/workqueue.h b/include/trace/workqueue.h
> index 7626523..ecb58f4 100644
> --- a/include/trace/workqueue.h
> +++ b/include/trace/workqueue.h
> @@ -1,25 +1,10 @@
> #ifndef __TRACE_WORKQUEUE_H
> #define __TRACE_WORKQUEUE_H
>
> -#include <linux/tracepoint.h>
> #include <linux/workqueue.h>
> #include <linux/sched.h>
> +#include <linux/tracepoint.h>
>
> -DECLARE_TRACE(workqueue_insertion,
> - TP_PROTO(struct task_struct *wq_thread, struct work_struct *work),
> - TP_ARGS(wq_thread, work));
> -
> -DECLARE_TRACE(workqueue_execution,
> - TP_PROTO(struct task_struct *wq_thread, struct work_struct *work),
> - TP_ARGS(wq_thread, work));
> -
> -/* Trace the creation of one workqueue thread on a cpu */
> -DECLARE_TRACE(workqueue_creation,
> - TP_PROTO(struct task_struct *wq_thread, int cpu),
> - TP_ARGS(wq_thread, cpu));
> -
> -DECLARE_TRACE(workqueue_destruction,
> - TP_PROTO(struct task_struct *wq_thread),
> - TP_ARGS(wq_thread));
> +#include <trace/workqueue_event_types.h>
>
> #endif /* __TRACE_WORKQUEUE_H */
> diff --git a/include/trace/workqueue_event_types.h b/include/trace/workqueue_event_types.h
> new file mode 100644
> index 0000000..ff65d47
> --- /dev/null
> +++ b/include/trace/workqueue_event_types.h
> @@ -0,0 +1,101 @@
> +
> +/* use <trace/workqueue.h> instead */
> +#ifndef TRACE_EVENT
> +# error Do not include this file directly.
> +# error Unless you know what you are doing.
> +#endif
> +
> +#undef TRACE_SYSTEM
> +#define TRACE_SYSTEM workqueue
> +
> +TRACE_EVENT(workqueue_insertion,
> +
> + TP_PROTO(struct task_struct *wq_thread, struct work_struct *work),
> +
> + TP_ARGS(wq_thread, work),
> +
> + TP_STRUCT__entry(
> + __array( char, thread_comm, TASK_COMM_LEN )
> + __field( pid_t, thread_pid )
> + __field( struct work_struct *, work )
> + __field( work_func_t, func )
> + ),
> +
> + TP_fast_assign(
> + memcpy(__entry->thread_comm, wq_thread->comm, TASK_COMM_LEN);
This is not about your patch but I see this pattern happen often. We should
start think about a way to use tracing_record_cmdline for that.
> + __entry->thread_pid = wq_thread->pid;
> + __entry->work = work;
> + __entry->func = work->func;
> + ),
> +
> + TP_printk("thread=%s:%d work=%p func=%p", __entry->thread_comm,
These pointer addresses are not very useful to display.
We can zap work and display the func as a %pF.
Not related to your patch: only the name of the func is useful,
not its asm offset. A format for raw func name without offset would
start to become very handy. I remember Andrew talked about that by the past.
I wonder which format we could use for that. %pf ?
> + __entry->thread_pid, __entry->work, __entry->func)
> +);
> +
> +TRACE_EVENT(workqueue_execution,
> +
> + TP_PROTO(struct task_struct *wq_thread, struct work_struct *work),
> +
> + TP_ARGS(wq_thread, work),
> +
> + TP_STRUCT__entry(
> + __array( char, thread_comm, TASK_COMM_LEN )
> + __field( pid_t, thread_pid )
> + __field( struct work_struct *, work )
> + __field( work_func_t, func )
> + ),
> +
> + TP_fast_assign(
> + memcpy(__entry->thread_comm, wq_thread->comm, TASK_COMM_LEN);
> + __entry->thread_pid = wq_thread->pid;
> + __entry->work = work;
> + __entry->func = work->func;
> + ),
> +
> + TP_printk("thread=%s:%d work=%p func=%p", __entry->thread_comm,
ditto.
> + __entry->thread_pid, __entry->work, __entry->func)
> +);
> +
> +/* Trace the creation of one workqueue thread on a cpu */
> +TRACE_EVENT(workqueue_creation,
> +
> + TP_PROTO(struct task_struct *wq_thread, int cpu),
> +
> + TP_ARGS(wq_thread, cpu),
> +
> + TP_STRUCT__entry(
> + __array( char, thread_comm, TASK_COMM_LEN )
> + __field( pid_t, thread_pid )
> + __field( int, cpu )
> + ),
> +
> + TP_fast_assign(
> + memcpy(__entry->thread_comm, wq_thread->comm, TASK_COMM_LEN);
> + __entry->thread_pid = wq_thread->pid;
> + __entry->cpu = cpu;
> + ),
> +
> + TP_printk("thread=%s:%d cpu=%d", __entry->thread_comm,
> + __entry->thread_pid, __entry->cpu)
> +);
> +
> +TRACE_EVENT(workqueue_destruction,
> +
> + TP_PROTO(struct task_struct *wq_thread),
> +
> + TP_ARGS(wq_thread),
> +
> + TP_STRUCT__entry(
> + __array( char, thread_comm, TASK_COMM_LEN )
> + __field( pid_t, thread_pid )
> + ),
> +
> + TP_fast_assign(
> + memcpy(__entry->thread_comm, wq_thread->comm, TASK_COMM_LEN);
> + __entry->thread_pid = wq_thread->pid;
> + ),
> +
> + TP_printk("thread=%s:%d", __entry->thread_comm, __entry->thread_pid)
> +);
> +
> +#undef TRACE_SYSTEM
But the rest looks fine.
Thanks!
Frederic.
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