Re: [PATCH v7 2/3] binder: add trace at free transaction.

[Todd Kjos]

On Tue, Aug 4, 2020 at 7:09 AM Frankie Chang <Frankie.Chang@xxxxxxxxxxxx> wrote:
>
> From: "Frankie.Chang" <Frankie.Chang@xxxxxxxxxxxx>
>
> Since the original trace_binder_transaction_received cannot
> precisely present the real finished time of transaction, adding a
> trace_binder_txn_latency_free at the point of free transaction
> may be more close to it.
>
> Signed-off-by: Frankie.Chang <Frankie.Chang@xxxxxxxxxxxx>

Acked-by: Todd Kjos <tkjos@xxxxxxxxxx>

> ---
>  drivers/android/binder.c       |   18 ++++++++++++++++++
>  drivers/android/binder_trace.h |   29 +++++++++++++++++++++++++++++
>  2 files changed, 47 insertions(+)
>
> diff --git a/drivers/android/binder.c b/drivers/android/binder.c
> index 2df146f..1bfadc2 100644
> --- a/drivers/android/binder.c
> +++ b/drivers/android/binder.c
> @@ -1508,6 +1508,20 @@ static void binder_free_txn_fixups(struct binder_transaction *t)
>         }
>  }
>
> +static void binder_txn_latency_free(struct binder_transaction *t)
> +{
> +       int from_proc, from_thread, to_proc, to_thread;
> +
> +       spin_lock(&t->lock);
> +       from_proc = t->from ? t->from->proc->pid : 0;
> +       from_thread = t->from ? t->from->pid : 0;
> +       to_proc = t->to_proc ? t->to_proc->pid : 0;
> +       to_thread = t->to_thread ? t->to_thread->pid : 0;
> +       spin_unlock(&t->lock);
> +
> +       trace_binder_txn_latency_free(t, from_proc, from_thread, to_proc, to_thread);
> +}
> +
>  static void binder_free_transaction(struct binder_transaction *t)
>  {
>         struct binder_proc *target_proc = t->to_proc;
> @@ -1518,6 +1532,8 @@ static void binder_free_transaction(struct binder_transaction *t)
>                         t->buffer->transaction = NULL;
>                 binder_inner_proc_unlock(target_proc);
>         }
> +       if (trace_binder_txn_latency_free_enabled())
> +               binder_txn_latency_free(t);
>         /*
>          * If the transaction has no target_proc, then
>          * t->buffer->transaction has already been cleared.
> @@ -3093,6 +3109,8 @@ static void binder_transaction(struct binder_proc *proc,
>         kfree(tcomplete);
>         binder_stats_deleted(BINDER_STAT_TRANSACTION_COMPLETE);
>  err_alloc_tcomplete_failed:
> +       if (trace_binder_txn_latency_free_enabled())
> +               binder_txn_latency_free(t);
>         kfree(t);
>         binder_stats_deleted(BINDER_STAT_TRANSACTION);
>  err_alloc_t_failed:
> diff --git a/drivers/android/binder_trace.h b/drivers/android/binder_trace.h
> index 6731c3c..eb2c53c 100644
> --- a/drivers/android/binder_trace.h
> +++ b/drivers/android/binder_trace.h
> @@ -95,6 +95,35 @@
>                   __entry->thread_todo)
>  );
>
> +TRACE_EVENT(binder_txn_latency_free,
> +       TP_PROTO(struct binder_transaction *t
> +                int from_proc, int from_thread
> +                int to_proc, int to_thread),
> +       TP_ARGS(t, from_proc, from_thread, to_proc, to_thread),
> +       TP_STRUCT__entry(
> +               __field(int, debug_id)
> +               __field(int, from_proc)
> +               __field(int, from_thread)
> +               __field(int, to_proc)
> +               __field(int, to_thread)
> +               __field(unsigned int, code)
> +               __field(unsigned int, flags)
> +       ),
> +       TP_fast_assign(
> +               __entry->debug_id = t->debug_id;
> +               __entry->from_proc = from_proc;
> +               __entry->from_thread = from_thread;
> +               __entry->to_proc = to_proc;
> +               __entry->to_thread = to_thread;
> +               __entry->code = t->code;
> +               __entry->flags = t->flags;
> +       ),
> +       TP_printk("transaction=%d from %d:%d to %d:%d flags=0x%x code=0x%x",
> +                 __entry->debug_id, __entry->from_proc, __entry->from_thread,
> +                 __entry->to_proc, __entry->to_thread, __entry->code,
> +                 __entry->flags)
> +);
> +
>  TRACE_EVENT(binder_transaction,
>         TP_PROTO(bool reply, struct binder_transaction *t,
>                  struct binder_node *target_node),
> --
> 1.7.9.5