diff options
| author | Frederic Weisbecker <fweisbec@gmail.com> | 2011-11-29 04:18:56 +0400 |
|---|---|---|
| committer | Paul E. McKenney <paulmck@linux.vnet.ibm.com> | 2011-12-11 22:32:07 +0400 |
| commit | b6fc6020140db437069d5bec447858fcfd64d31c (patch) | |
| tree | 43b4f6aa420bd636a30116443f2417cd2176a679 /kernel/rcutree.c | |
| parent | 7cb92499000e3c86dae653077b1465458a039ef6 (diff) | |
| download | linux-b6fc6020140db437069d5bec447858fcfd64d31c.tar.xz | |
rcu: Don't check irq nesting from rcu idle entry/exit
Because tasks do not nest, rcu_idle_enter() and rcu_idle_exit() do
not need to check for nesting. This commit therefore moves nesting
checks from rcu_idle_enter_common() to rcu_irq_exit() and from
rcu_idle_exit_common() to rcu_irq_enter().
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Josh Triplett <josh@joshtriplett.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Diffstat (limited to 'kernel/rcutree.c')
| -rw-r--r-- | kernel/rcutree.c | 18 |
1 files changed, 8 insertions, 10 deletions
diff --git a/kernel/rcutree.c b/kernel/rcutree.c index bf085d7f6a3f..860c02c7c959 100644 --- a/kernel/rcutree.c +++ b/kernel/rcutree.c @@ -350,10 +350,6 @@ static int rcu_implicit_offline_qs(struct rcu_data *rdp) */ static void rcu_idle_enter_common(struct rcu_dynticks *rdtp, long long oldval) { - if (rdtp->dynticks_nesting) { - trace_rcu_dyntick("--=", oldval, rdtp->dynticks_nesting); - return; - } trace_rcu_dyntick("Start", oldval, rdtp->dynticks_nesting); if (!is_idle_task(current)) { struct task_struct *idle = idle_task(smp_processor_id()); @@ -426,7 +422,10 @@ void rcu_irq_exit(void) oldval = rdtp->dynticks_nesting; rdtp->dynticks_nesting--; WARN_ON_ONCE(rdtp->dynticks_nesting < 0); - rcu_idle_enter_common(rdtp, oldval); + if (rdtp->dynticks_nesting) + trace_rcu_dyntick("--=", oldval, rdtp->dynticks_nesting); + else + rcu_idle_enter_common(rdtp, oldval); local_irq_restore(flags); } @@ -439,10 +438,6 @@ void rcu_irq_exit(void) */ static void rcu_idle_exit_common(struct rcu_dynticks *rdtp, long long oldval) { - if (oldval) { - trace_rcu_dyntick("++=", oldval, rdtp->dynticks_nesting); - return; - } smp_mb__before_atomic_inc(); /* Force ordering w/previous sojourn. */ atomic_inc(&rdtp->dynticks); /* CPUs seeing atomic_inc() must see later RCU read-side crit sects */ @@ -518,7 +513,10 @@ void rcu_irq_enter(void) oldval = rdtp->dynticks_nesting; rdtp->dynticks_nesting++; WARN_ON_ONCE(rdtp->dynticks_nesting == 0); - rcu_idle_exit_common(rdtp, oldval); + if (oldval) + trace_rcu_dyntick("++=", oldval, rdtp->dynticks_nesting); + else + rcu_idle_exit_common(rdtp, oldval); local_irq_restore(flags); } |