On Fri, 13 Apr 2018 15:07:17 +0200
Steffen Maier <maier@xxxxxxxxxxxxx> wrote:
> Just like blktrace distinguishes explicit and schedule by means of
> BLK_TA_UNPLUG_IO and BLK_TA_UNPLUG_TIMER, actually make use of the
> existing argument "explicit" to distinguish the two cases in the one
> common tracepoint block_unplug.
>
> Complements v2.6.39 commit 49cac01e1fa7 ("block: make unplug timer trace
> event correspond to the schedule() unplug") and commit d9c978331790
> ("block: remove block_unplug_timer() trace point").
>
> Signed-off-by: Steffen Maier <maier@xxxxxxxxxxxxx>
> ---
> include/trace/events/block.h | 10 +++++++++-
> 1 file changed, 9 insertions(+), 1 deletion(-)
>
> diff --git a/include/trace/events/block.h b/include/trace/events/block.h
> index 81b43f5bdf23..a13613d27cee 100644
> --- a/include/trace/events/block.h
> +++ b/include/trace/events/block.h
> @@ -470,6 +470,11 @@ TRACE_EVENT(block_plug,
> TP_printk("[%s]", __entry->comm)
> );
>
> +#define show_block_unplug_explicit(val) \
> + __print_symbolic(val, \
> + {false, "schedule"}, \
> + {true, "explicit"})
That's new. I haven't seen "true"/"false" values used for
print_symbolic before. But could you please use 1 and 0 instead, because
perf and trace-cmd won't be able to parse that. I could update
libtraceevent to handle it, but really, the first parameter is suppose
to be numeric.
-- Steve
> +
> DECLARE_EVENT_CLASS(block_unplug,
>
> TP_PROTO(struct request_queue *q, unsigned int depth, bool explicit),
> @@ -478,15 +483,18 @@ DECLARE_EVENT_CLASS(block_unplug,
>
> TP_STRUCT__entry(
> __field( int, nr_rq )
> + __field( bool, explicit )
> __array( char, comm, TASK_COMM_LEN )
> ),
>
> TP_fast_assign(
> __entry->nr_rq = depth;
> + __entry->explicit = explicit;
> memcpy(__entry->comm, current->comm, TASK_COMM_LEN);
> ),
>
> - TP_printk("[%s] %d", __entry->comm, __entry->nr_rq)
> + TP_printk("[%s] %d %s", __entry->comm, __entry->nr_rq,
> + show_block_unplug_explicit(__entry->explicit))
> );
>
> /**
