src/patches/suse-2.6.27.25/patches.trace/markers-use-rcu-read-lock-sched.patch

   1 From: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
   2 Subject: Markers use rcu_read_lock_sched()
   3
   4 Use the new rcu_read_lock_sched/unlock_sched() in marker code around the call
   5 site instead of preempt_disable/enable(). It helps reviewing the code more
   6 easily.
   7
   8 Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
   9 CC: Peter Zijlstra <peterz@infradead.org>
  10 CC: Paul E McKenney <paulmck@linux.vnet.ibm.com>
  11 CC: akpm@linux-foundation.org
  12 Acked-by: Jan Blunck <jblunck@suse.de>
  13 ---
  14  kernel/marker.c |   16 ++++++++--------
  15  1 file changed, 8 insertions(+), 8 deletions(-)
  16
  17 Index: b/kernel/marker.c
  18 ===================================================================
  19 --- a/kernel/marker.c
  20 +++ b/kernel/marker.c
  21 @@ -103,11 +103,11 @@ void marker_probe_cb(const struct marker
  22         char ptype;
  23
  24         /*
  25 -        * preempt_disable does two things : disabling preemption to make sure
  26 -        * the teardown of the callbacks can be done correctly when they are in
  27 -        * modules and they insure RCU read coherency.
  28 +        * rcu_read_lock_sched does two things : disabling preemption to make
  29 +        * sure the teardown of the callbacks can be done correctly when they
  30 +        * are in modules and they insure RCU read coherency.
  31          */
  32 -       preempt_disable();
  33 +       rcu_read_lock_sched();
  34         ptype = mdata->ptype;
  35         if (likely(!ptype)) {
  36                 marker_probe_func *func;
  37 @@ -145,7 +145,7 @@ void marker_probe_cb(const struct marker
  38                         va_end(args);
  39                 }
  40         }
  41 -       preempt_enable();
  42 +       rcu_read_unlock_sched();
  43  }
  44  EXPORT_SYMBOL_GPL(marker_probe_cb);
  45
  46 @@ -162,7 +162,7 @@ void marker_probe_cb_noarg(const struct
  47         va_list args;   /* not initialized */
  48         char ptype;
  49
  50 -       preempt_disable();
  51 +       rcu_read_lock_sched();
  52         ptype = mdata->ptype;
  53         if (likely(!ptype)) {
  54                 marker_probe_func *func;
  55 @@ -195,7 +195,7 @@ void marker_probe_cb_noarg(const struct
  56                         multi[i].func(multi[i].probe_private, call_private,
  57                                 mdata->format, &args);
  58         }
  59 -       preempt_enable();
  60 +       rcu_read_unlock_sched();
  61  }
  62  EXPORT_SYMBOL_GPL(marker_probe_cb_noarg);
  63
  64 @@ -560,7 +560,7 @@ static int set_marker(struct marker_entr
  65   * Disable a marker and its probe callback.
  66   * Note: only waiting an RCU period after setting elem->call to the empty
  67   * function insures that the original callback is not used anymore. This insured
  68 - * by preempt_disable around the call site.
  69 + * by rcu_read_lock_sched around the call site.
  70   */
  71  static void disable_marker(struct marker *elem)
  72  {