diff options
| author | Paul E. McKenney <paulmck@linux.vnet.ibm.com> | 2009-08-22 13:56:51 -0700 |
|---|---|---|
| committer | Ingo Molnar <mingo@elte.hu> | 2009-08-23 10:32:39 +0200 |
| commit | a157229cabd6dd8cfa82525fc9bf730c94cc9ac2 (patch) | |
| tree | 886013efc2f25dab915640acf46151fac7ae57b4 /kernel | |
| parent | 22f00b69f6a7e1e18e821979a23e8307c2de9888 (diff) | |
rcu: Simplify rcu_pending()/rcu_check_callbacks() API
All calls from outside RCU are of the form:
if (rcu_pending(cpu))
rcu_check_callbacks(cpu, user);
This is silly, instead we put a call to rcu_pending() in
rcu_check_callbacks(), and then make the outside calls be to
rcu_check_callbacks(). This cuts down on the code a bit and
also gives the compiler a better chance of optimizing.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: laijs@cn.fujitsu.com
Cc: dipankar@in.ibm.com
Cc: akpm@linux-foundation.org
Cc: mathieu.desnoyers@polymtl.ca
Cc: josht@linux.vnet.ibm.com
Cc: dvhltc@us.ibm.com
Cc: niv@us.ibm.com
Cc: peterz@infradead.org
Cc: rostedt@goodmis.org
LKML-Reference: <125097461311-git-send-email->
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/rcupreempt.c | 10 | ||||
| -rw-r--r-- | kernel/rcutree.c | 5 | ||||
| -rw-r--r-- | kernel/timer.c | 3 |
3 files changed, 13 insertions, 5 deletions
diff --git a/kernel/rcupreempt.c b/kernel/rcupreempt.c index 7d777c9f394..0053ce56e32 100644 --- a/kernel/rcupreempt.c +++ b/kernel/rcupreempt.c @@ -159,6 +159,8 @@ static DEFINE_PER_CPU_SHARED_ALIGNED(struct rcu_dyntick_sched, rcu_dyntick_sched .dynticks = 1, }; +static int rcu_pending(int cpu); + void rcu_sched_qs(int cpu) { struct rcu_dyntick_sched *rdssp = &per_cpu(rcu_dyntick_sched, cpu); @@ -961,7 +963,10 @@ static void rcu_check_mb(int cpu) void rcu_check_callbacks(int cpu, int user) { unsigned long flags; - struct rcu_data *rdp = RCU_DATA_CPU(cpu); + struct rcu_data *rdp; + + if (!rcu_pending(cpu)) + return; /* if nothing for RCU to do. */ /* * If this CPU took its interrupt from user mode or from the @@ -976,6 +981,7 @@ void rcu_check_callbacks(int cpu, int user) * CPUs to happen after any such write. */ + rdp = RCU_DATA_CPU(cpu); if (user || (idle_cpu(cpu) && !in_softirq() && hardirq_count() <= (1 << HARDIRQ_SHIFT))) { @@ -1382,7 +1388,7 @@ int rcu_needs_cpu(int cpu) rdp->waitschedlist != NULL); } -int rcu_pending(int cpu) +static int rcu_pending(int cpu) { struct rcu_data *rdp = RCU_DATA_CPU(cpu); diff --git a/kernel/rcutree.c b/kernel/rcutree.c index 7c515082ae8..4ce3adcfa94 100644 --- a/kernel/rcutree.c +++ b/kernel/rcutree.c @@ -111,6 +111,7 @@ static int qhimark = 10000; /* If this many pending, ignore blimit. */ static int qlowmark = 100; /* Once only this many pending, use blimit. */ static void force_quiescent_state(struct rcu_state *rsp, int relaxed); +static int rcu_pending(int cpu); /* * Return the number of RCU-sched batches processed thus far for debug & stats. @@ -974,6 +975,8 @@ static void rcu_do_batch(struct rcu_data *rdp) */ void rcu_check_callbacks(int cpu, int user) { + if (!rcu_pending(cpu)) + return; /* if nothing for RCU to do. */ if (user || (idle_cpu(cpu) && rcu_scheduler_active && !in_softirq() && hardirq_count() <= (1 << HARDIRQ_SHIFT))) { @@ -1329,7 +1332,7 @@ static int __rcu_pending(struct rcu_state *rsp, struct rcu_data *rdp) * by the current CPU, returning 1 if so. This function is part of the * RCU implementation; it is -not- an exported member of the RCU API. */ -int rcu_pending(int cpu) +static int rcu_pending(int cpu) { return __rcu_pending(&rcu_sched_state, &per_cpu(rcu_sched_data, cpu)) || __rcu_pending(&rcu_bh_state, &per_cpu(rcu_bh_data, cpu)); diff --git a/kernel/timer.c b/kernel/timer.c index a7f07d5a624..a3d25f41501 100644 --- a/kernel/timer.c +++ b/kernel/timer.c @@ -1156,8 +1156,7 @@ void update_process_times(int user_tick) /* Note: this timer irq context must be accounted for as well. */ account_process_tick(p, user_tick); run_local_timers(); - if (rcu_pending(cpu)) - rcu_check_callbacks(cpu, user_tick); + rcu_check_callbacks(cpu, user_tick); printk_tick(); scheduler_tick(); run_posix_cpu_timers(p); |