Commit 1acaa1b2 authored Mar 05, 2010 by Arnaldo Carvalho de Melo Committed by Steven Rostedt Mar 05, 2010

tracing: Update the comm field in the right variable in update_max_tr



The latency output showed:

 #    | task: -3 (uid:0 nice:0 policy:1 rt_prio:99)

The comm is missing in the "task:" and it looks like a minus 3 is
the output. The correct display should be:

 #    | task: migration/0-3 (uid:0 nice:0 policy:1 rt_prio:99)

The problem is that the comm is being stored in the wrong data
structure. The max_tr.data[cpu] is what stores the comm, not the
tr->data[cpu].

Before this patch the max_tr.data[cpu]->comm was zeroed and the /debug/trace
ended up showing just the '-' sign followed by the pid.

Also remove a needless initialization of max_data.

Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
LKML-Reference: <1267824230-23861-1-git-send-email-acme@infradead.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>

parent a094fe04

kernel/trace/trace.c

+2 −2

Original line number	Diff line number	Diff line
		@@ -592,7 +592,7 @@ static void
		__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 *max_data = tr->data[cpu];
		struct trace_array_cpu *max_data;

		max_tr.cpu = cpu;
		max_tr.time_start = data->preempt_timestamp;
		@@ -602,7 +602,7 @@ __update_max_tr(struct trace_array tr, struct task_struct tsk, int cpu)
		max_data->critical_start = data->critical_start;
		max_data->critical_end = data->critical_end;

		memcpy(data->comm, tsk->comm, TASK_COMM_LEN);
		memcpy(max_data->comm, tsk->comm, TASK_COMM_LEN);
		max_data->pid = tsk->pid;
		max_data->uid = task_uid(tsk);
		max_data->nice = tsk->static_prio - 20 - MAX_RT_PRIO;

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