Commit 8248ac05 authored by Steven Rostedt's avatar Steven Rostedt Committed by Steven Rostedt
Browse files

tracing: print out start and stop in latency traces 



During development of the tracer, we would copy information from
the live tracer to the max tracer with one memcpy. Since then we
added a generic ring buffer and we handle the copies differently now.
Unfortunately, we never copied the critical section information, and
we lost the output:

 #  => started at: kmem_cache_alloc
 #  => ended at:   kmem_cache_alloc

This patch adds back the critical start and end copying as well as
removes the unused "trace_idx" and "overrun" fields of the
trace_array_cpu structure.

Signed-off-by: default avatarSteven Rostedt <rostedt@goodmis.org>
parent 077c5407

kernel/trace/trace.c

+11 −8
Original line number Original line Diff line number Diff line
@@ -407,19 +407,22 @@ static void 
__update_max_tr(struct trace_array *tr, struct task_struct *tsk, int cpu)

__update_max_tr(struct trace_array *tr, struct task_struct *tsk, int cpu)

{

{

	struct trace_array_cpu *data = tr->data[cpu];

	struct trace_array_cpu *data = tr->data[cpu];

	struct trace_array_cpu *max_data = tr->data[cpu];





	max_tr.cpu = cpu;

	max_tr.cpu = cpu;

	max_tr.time_start = data->preempt_timestamp;

	max_tr.time_start = data->preempt_timestamp;





	data = max_tr.data[cpu];

	max_data = max_tr.data[cpu];

	data->saved_latency = tracing_max_latency;

	max_data->saved_latency = tracing_max_latency;

	max_data->critical_start = data->critical_start;

	max_data->critical_end = data->critical_end;





	memcpy(data->comm, tsk->comm, TASK_COMM_LEN);

	memcpy(data->comm, tsk->comm, TASK_COMM_LEN);

	data->pid = tsk->pid;

	max_data->pid = tsk->pid;

	data->uid = task_uid(tsk);

	max_data->uid = task_uid(tsk);

	data->nice = tsk->static_prio - 20 - MAX_RT_PRIO;

	max_data->nice = tsk->static_prio - 20 - MAX_RT_PRIO;

	data->policy = tsk->policy;

	max_data->policy = tsk->policy;

	data->rt_priority = tsk->rt_priority;

	max_data->rt_priority = tsk->rt_priority;





	/* record this tasks comm */

	/* record this tasks comm */

	tracing_record_cmdline(tsk);

	tracing_record_cmdline(tsk);
@@ -1501,7 +1504,7 @@ print_trace_header(struct seq_file *m, struct trace_iterator *iter) 
		seq_puts(m, "\n#  => ended at:   ");

		seq_puts(m, "\n#  => ended at:   ");

		seq_print_ip_sym(&iter->seq, data->critical_end, sym_flags);

		seq_print_ip_sym(&iter->seq, data->critical_end, sym_flags);

		trace_print_seq(m, &iter->seq);

		trace_print_seq(m, &iter->seq);

		seq_puts(m, "#\n");

		seq_puts(m, "\n#\n");

	}

	}





	seq_puts(m, "#\n");

	seq_puts(m, "#\n");

kernel/trace/trace.h

+0 −3
Original line number Original line Diff line number Diff line
@@ -234,9 +234,6 @@ struct trace_array_cpu { 
	atomic_t		disabled;

	atomic_t		disabled;

	void			*buffer_page;	/* ring buffer spare */

	void			*buffer_page;	/* ring buffer spare */





	/* these fields get copied into max-trace: */

	unsigned long		trace_idx;

	unsigned long		overrun;

	unsigned long		saved_latency;

	unsigned long		saved_latency;

	unsigned long		critical_start;

	unsigned long		critical_start;

	unsigned long		critical_end;

	unsigned long		critical_end;

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