Commit 29b1a8ad authored by Joel Fernandes's avatar Joel Fernandes Committed by Steven Rostedt (VMware)
Browse files

tracing: Attempt to record other information even if some fail 

In recent patches where we record comm and tgid at the same time, we skip
continuing to record if any fail. Fix that by trying to record as many things
as we can even if some couldn't be recorded. If any information isn't recorded,
then we don't set trace_taskinfo_save as before.

Link: http://lkml.kernel.org/r/20170706230023.17942-3-joelaf@google.com



Cc: kernel-team@android.com
Cc: Ingo Molnar <mingo@redhat.com>
Signed-off-by: default avatarJoel Fernandes <joelaf@google.com>
Signed-off-by: default avatarSteven Rostedt (VMware) <rostedt@goodmis.org>
parent bd45d34d

kernel/trace/trace.c

+24 −8
Original line number Diff line number Diff line
@@ -2037,11 +2037,20 @@ static bool tracing_record_taskinfo_skip(int flags) 
 */

void tracing_record_taskinfo(struct task_struct *task, int flags)

{

	bool done;



	if (tracing_record_taskinfo_skip(flags))

		return;

	if ((flags & TRACE_RECORD_CMDLINE) && !trace_save_cmdline(task))

		return;

	if ((flags & TRACE_RECORD_TGID) && !trace_save_tgid(task))



	/*

	 * Record as much task information as possible. If some fail, continue

	 * to try to record the others.

	 */

	done = !(flags & TRACE_RECORD_CMDLINE) || trace_save_cmdline(task);

	done &= !(flags & TRACE_RECORD_TGID) || trace_save_tgid(task);



	/* If recording any information failed, retry again soon. */

	if (!done)

		return;



	__this_cpu_write(trace_taskinfo_save, false);
@@ -2058,15 +2067,22 @@ void tracing_record_taskinfo(struct task_struct *task, int flags) 
void tracing_record_taskinfo_sched_switch(struct task_struct *prev,

					  struct task_struct *next, int flags)

{

	bool done;



	if (tracing_record_taskinfo_skip(flags))

		return;



	if ((flags & TRACE_RECORD_CMDLINE) &&

	    (!trace_save_cmdline(prev) || !trace_save_cmdline(next)))

		return;

	/*

	 * Record as much task information as possible. If some fail, continue

	 * to try to record the others.

	 */

	done  = !(flags & TRACE_RECORD_CMDLINE) || trace_save_cmdline(prev);

	done &= !(flags & TRACE_RECORD_CMDLINE) || trace_save_cmdline(next);

	done &= !(flags & TRACE_RECORD_TGID) || trace_save_tgid(prev);

	done &= !(flags & TRACE_RECORD_TGID) || trace_save_tgid(next);



	if ((flags & TRACE_RECORD_TGID) &&

	    (!trace_save_tgid(prev) || !trace_save_tgid(next)))

	/* If recording any information failed, retry again soon. */

	if (!done)

		return;



	__this_cpu_write(trace_taskinfo_save, false);

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