Commit-ID: 274529ba9bda86c91c2c06da3a641aaf617dd30f
Gitweb: http://git.kernel.org/tip/274529ba9bda86c91c2c06da3a641aaf617dd30f
Author: Paul E. McKenney <paulmck@xxxxxxxxxxxxxxxxxx>
AuthorDate: Mon, 21 Mar 2016 19:46:04 -0700
Committer: Paul E. McKenney <paulmck@xxxxxxxxxxxxxxxxxx>
CommitDate: Thu, 31 Mar 2016 13:29:08 -0700
rcu: Consolidate dumping of ftrace buffer
This commit consolidates a couple definitions and several calls for
single-shot ftrace-buffer dumping.
Signed-off-by: Paul E. McKenney <paulmck@xxxxxxxxxxxxxxxxxx>
---
include/linux/rcupdate.h | 13 +++++++++++++
kernel/rcu/rcutorture.c | 17 +++--------------
kernel/rcu/tree.c | 4 ++--
3 files changed, 18 insertions(+), 16 deletions(-)
diff --git a/include/linux/rcupdate.h b/include/linux/rcupdate.h
index 2657aff..45de591 100644
--- a/include/linux/rcupdate.h
+++ b/include/linux/rcupdate.h
@@ -1144,4 +1144,17 @@ static inline void rcu_sysidle_force_exit(void)
#endif /* #else #ifdef CONFIG_NO_HZ_FULL_SYSIDLE */
+/*
+ * Dump the ftrace buffer, but only one time per callsite per boot.
+ */
+#define rcu_ftrace_dump(oops_dump_mode) \
+do { \
+ static atomic_t ___rfd_beenhere = ATOMIC_INIT(0); \
+ \
+ if (!atomic_read(&___rfd_beenhere) && \
+ !atomic_xchg(&___rfd_beenhere, 1)) \
+ ftrace_dump(oops_dump_mode); \
+} while (0)
+
+
#endif /* __LINUX_RCUPDATE_H */
diff --git a/kernel/rcu/rcutorture.c b/kernel/rcu/rcutorture.c
index 250ea67..463867c 100644
--- a/kernel/rcu/rcutorture.c
+++ b/kernel/rcu/rcutorture.c
@@ -1082,17 +1082,6 @@ rcu_torture_fakewriter(void *arg)
return 0;
}
-static void rcutorture_trace_dump(void)
-{
- static atomic_t beenhere = ATOMIC_INIT(0);
-
- if (atomic_read(&beenhere))
- return;
- if (atomic_xchg(&beenhere, 1) != 0)
- return;
- ftrace_dump(DUMP_ALL);
-}
-
/*
* RCU torture reader from timer handler. Dereferences rcu_torture_current,
* incrementing the corresponding element of the pipeline array. The
@@ -1142,7 +1131,7 @@ static void rcu_torture_timer(unsigned long unused)
if (pipe_count > 1) {
do_trace_rcu_torture_read(cur_ops->name, &p->rtort_rcu, ts,
started, completed);
- rcutorture_trace_dump();
+ rcu_ftrace_dump(DUMP_ALL);
}
__this_cpu_inc(rcu_torture_count[pipe_count]);
completed = completed - started;
@@ -1215,7 +1204,7 @@ rcu_torture_reader(void *arg)
if (pipe_count > 1) {
do_trace_rcu_torture_read(cur_ops->name, &p->rtort_rcu,
ts, started, completed);
- rcutorture_trace_dump();
+ rcu_ftrace_dump(DUMP_ALL);
}
__this_cpu_inc(rcu_torture_count[pipe_count]);
completed = completed - started;
@@ -1333,7 +1322,7 @@ rcu_torture_stats_print(void)
rcu_torture_writer_state,
gpnum, completed, flags);
show_rcu_gp_kthreads();
- rcutorture_trace_dump();
+ rcu_ftrace_dump(DUMP_ALL);
}
rtcv_snap = rcu_torture_current_version;
}
diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c
index 9a535a8..531a328 100644
--- a/kernel/rcu/tree.c
+++ b/kernel/rcu/tree.c
@@ -637,7 +637,7 @@ static void rcu_eqs_enter_common(long long oldval, bool user)
idle_task(smp_processor_id());
trace_rcu_dyntick(TPS("Error on entry: not idle task"), oldval, 0);
- ftrace_dump(DUMP_ORIG);
+ rcu_ftrace_dump(DUMP_ORIG);
WARN_ONCE(1, "Current pid: %d comm: %s / Idle pid: %d comm: %s",
current->pid, current->comm,
idle->pid, idle->comm); /* must be idle task! */
@@ -799,7 +799,7 @@ static void rcu_eqs_exit_common(long long oldval, int user)
trace_rcu_dyntick(TPS("Error on exit: not idle task"),
oldval, rdtp->dynticks_nesting);
- ftrace_dump(DUMP_ORIG);
+ rcu_ftrace_dump(DUMP_ORIG);
WARN_ONCE(1, "Current pid: %d comm: %s / Idle pid: %d comm: %s",
current->pid, current->comm,
idle->pid, idle->comm); /* must be idle task! */
--
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