rt-patches/0302-trace-Use-rcuidle-version-for-preemptoff_hist-trace-.patch

   1 From aca5b8f636abf1517bef36987a35c3097bdef90a Mon Sep 17 00:00:00 2001
   2 From: Yang Shi <yang.shi@windriver.com>
   3 Date: Tue, 23 Feb 2016 13:23:23 -0800
   4 Subject: [PATCH 302/366] trace: Use rcuidle version for preemptoff_hist trace
   5  point
   6
   7 When running -rt kernel with both PREEMPT_OFF_HIST and LOCKDEP enabled,
   8 the below error is reported:
   9
  10  [ INFO: suspicious RCU usage. ]
  11  4.4.1-rt6 #1 Not tainted
  12  include/trace/events/hist.h:31 suspicious rcu_dereference_check() usage!
  13
  14  other info that might help us debug this:
  15
  16  RCU used illegally from idle CPU!
  17  rcu_scheduler_active = 1, debug_locks = 0
  18  RCU used illegally from extended quiescent state!
  19  no locks held by swapper/0/0.
  20
  21  stack backtrace:
  22  CPU: 0 PID: 0 Comm: swapper/0 Not tainted 4.4.1-rt6-WR8.0.0.0_standard #1
  23  Stack : 0000000000000006 0000000000000000 ffffffff81ca8c38 ffffffff81c8fc80
  24     ffffffff811bdd68 ffffffff81cb0000 0000000000000000 ffffffff81cb0000
  25     0000000000000000 0000000000000000 0000000000000004 0000000000000000
  26     0000000000000004 ffffffff811bdf50 0000000000000000 ffffffff82b60000
  27     0000000000000000 ffffffff812897ac ffffffff819f0000 000000000000000b
  28     ffffffff811be460 ffffffff81b7c588 ffffffff81c8fc80 0000000000000000
  29     0000000000000000 ffffffff81ec7f88 ffffffff81d70000 ffffffff81b70000
  30     ffffffff81c90000 ffffffff81c3fb00 ffffffff81c3fc28 ffffffff815e6f98
  31     0000000000000000 ffffffff81c8fa87 ffffffff81b70958 ffffffff811bf2c4
  32     0707fe32e8d60ca5 ffffffff81126d60 0000000000000000 0000000000000000
  33     ...
  34  Call Trace:
  35  [<ffffffff81126d60>] show_stack+0xe8/0x108
  36  [<ffffffff815e6f98>] dump_stack+0x88/0xb0
  37  [<ffffffff8124b88c>] time_hardirqs_off+0x204/0x300
  38  [<ffffffff811aa5dc>] trace_hardirqs_off_caller+0x24/0xe8
  39  [<ffffffff811a4ec4>] cpu_startup_entry+0x39c/0x508
  40  [<ffffffff81d7dc68>] start_kernel+0x584/0x5a0
  41
  42 Replace regular trace_preemptoff_hist to rcuidle version to avoid the error.
  43
  44 Signed-off-by: Yang Shi <yang.shi@windriver.com>
  45 Cc: bigeasy@linutronix.de
  46 Cc: rostedt@goodmis.org
  47 Cc: linux-rt-users@vger.kernel.org
  48 Link: http://lkml.kernel.org/r/1456262603-10075-1-git-send-email-yang.shi@windriver.com
  49 Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
  50 ---
  51  kernel/trace/trace_irqsoff.c | 8 ++++----
  52  1 file changed, 4 insertions(+), 4 deletions(-)
  53
  54 diff --git a/kernel/trace/trace_irqsoff.c b/kernel/trace/trace_irqsoff.c
  55 index 5c3fcb7..553e712 100644
  56 --- a/kernel/trace/trace_irqsoff.c
  57 +++ b/kernel/trace/trace_irqsoff.c
  58 @@ -425,13 +425,13 @@ void start_critical_timings(void)
  59  {
  60         if (preempt_trace() || irq_trace())
  61                 start_critical_timing(CALLER_ADDR0, CALLER_ADDR1);
  62 -       trace_preemptirqsoff_hist(TRACE_START, 1);
  63 +       trace_preemptirqsoff_hist_rcuidle(TRACE_START, 1);
  64  }
  65  EXPORT_SYMBOL_GPL(start_critical_timings);
  66
  67  void stop_critical_timings(void)
  68  {
  69 -       trace_preemptirqsoff_hist(TRACE_STOP, 0);
  70 +       trace_preemptirqsoff_hist_rcuidle(TRACE_STOP, 0);
  71         if (preempt_trace() || irq_trace())
  72                 stop_critical_timing(CALLER_ADDR0, CALLER_ADDR1);
  73  }
  74 @@ -441,7 +441,7 @@ EXPORT_SYMBOL_GPL(stop_critical_timings);
  75  #ifdef CONFIG_PROVE_LOCKING
  76  void time_hardirqs_on(unsigned long a0, unsigned long a1)
  77  {
  78 -       trace_preemptirqsoff_hist(IRQS_ON, 0);
  79 +       trace_preemptirqsoff_hist_rcuidle(IRQS_ON, 0);
  80         if (!preempt_trace() && irq_trace())
  81                 stop_critical_timing(a0, a1);
  82  }
  83 @@ -450,7 +450,7 @@ void time_hardirqs_off(unsigned long a0, unsigned long a1)
  84  {
  85         if (!preempt_trace() && irq_trace())
  86                 start_critical_timing(a0, a1);
  87 -       trace_preemptirqsoff_hist(IRQS_OFF, 1);
  88 +       trace_preemptirqsoff_hist_rcuidle(IRQS_OFF, 1);
  89  }
  90
  91  #else /* !CONFIG_PROVE_LOCKING */
  92 --
  93 1.9.1
  94