From 274529ba9bda86c91c2c06da3a641aaf617dd30f Mon Sep 17 00:00:00 2001 From: "Paul E. McKenney" Date: Mon, 21 Mar 2016 19:46:04 -0700 Subject: [PATCH] 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 --- 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 2657aff2725b..45de591657a6 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 250ea67c1615..463867c43221 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 9a535a86e732..531a328076bd 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! */ -- 2.39.5