[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-ID: <20120615220824.GX31184@leaf>
Date: Fri, 15 Jun 2012 15:08:24 -0700
From: Josh Triplett <josh@...htriplett.org>
To: "Paul E. McKenney" <paulmck@...ux.vnet.ibm.com>
Cc: linux-kernel@...r.kernel.org, mingo@...e.hu, laijs@...fujitsu.com,
dipankar@...ibm.com, akpm@...ux-foundation.org,
mathieu.desnoyers@...ymtl.ca, niv@...ibm.com, tglx@...utronix.de,
peterz@...radead.org, rostedt@...dmis.org, Valdis.Kletnieks@...edu,
dhowells@...hat.com, eric.dumazet@...il.com, darren@...art.com,
fweisbec@...il.com, patches@...aro.org,
"Paul E. McKenney" <paul.mckenney@...aro.org>
Subject: Re: [PATCH tip/core/rcu 04/15] rcu: Place pointer to call_rcu() in
rcu_data structure
On Fri, Jun 15, 2012 at 02:05:59PM -0700, Paul E. McKenney wrote:
> From: "Paul E. McKenney" <paul.mckenney@...aro.org>
>
> This is a preparatory commit for increasing rcu_barrier()'s concurrency.
> It adds a pointer in the rcu_data structure to the corresponding call_rcu()
> function. This allows a pointer to the rcu_data structure to imply the
> function pointer, which allows _rcu_barrier() state to be placed in the
> rcu_state structure.
>
> Signed-off-by: Paul E. McKenney <paul.mckenney@...aro.org>
> Signed-off-by: Paul E. McKenney <paulmck@...ux.vnet.ibm.com>
Reviewed-by: Josh Triplett <josh@...htriplett.org>
> kernel/rcutree.c | 27 ++++++++++++---------------
> kernel/rcutree.h | 2 ++
> kernel/rcutree_plugin.h | 5 +++--
> 3 files changed, 17 insertions(+), 17 deletions(-)
>
> diff --git a/kernel/rcutree.c b/kernel/rcutree.c
> index 8ce1b1d..8b3ab4e 100644
> --- a/kernel/rcutree.c
> +++ b/kernel/rcutree.c
> @@ -62,8 +62,9 @@
>
> static struct lock_class_key rcu_node_class[RCU_NUM_LVLS];
>
> -#define RCU_STATE_INITIALIZER(sname) { \
> +#define RCU_STATE_INITIALIZER(sname, cr) { \
> .level = { &sname##_state.node[0] }, \
> + .call = cr, \
> .fqs_state = RCU_GP_IDLE, \
> .gpnum = -300, \
> .completed = -300, \
> @@ -76,10 +77,11 @@ static struct lock_class_key rcu_node_class[RCU_NUM_LVLS];
> .name = #sname, \
> }
>
> -struct rcu_state rcu_sched_state = RCU_STATE_INITIALIZER(rcu_sched);
> +struct rcu_state rcu_sched_state =
> + RCU_STATE_INITIALIZER(rcu_sched, call_rcu_sched);
> DEFINE_PER_CPU(struct rcu_data, rcu_sched_data);
>
> -struct rcu_state rcu_bh_state = RCU_STATE_INITIALIZER(rcu_bh);
> +struct rcu_state rcu_bh_state = RCU_STATE_INITIALIZER(rcu_bh, call_rcu_bh);
> DEFINE_PER_CPU(struct rcu_data, rcu_bh_data);
>
> static struct rcu_state *rcu_state;
> @@ -2279,21 +2281,17 @@ static void rcu_barrier_func(void *type)
> {
> int cpu = smp_processor_id();
> struct rcu_head *head = &per_cpu(rcu_barrier_head, cpu);
> - void (*call_rcu_func)(struct rcu_head *head,
> - void (*func)(struct rcu_head *head));
> + struct rcu_state *rsp = type;
>
> atomic_inc(&rcu_barrier_cpu_count);
> - call_rcu_func = type;
> - call_rcu_func(head, rcu_barrier_callback);
> + rsp->call(head, rcu_barrier_callback);
> }
>
> /*
> * Orchestrate the specified type of RCU barrier, waiting for all
> * RCU callbacks of the specified type to complete.
> */
> -static void _rcu_barrier(struct rcu_state *rsp,
> - void (*call_rcu_func)(struct rcu_head *head,
> - void (*func)(struct rcu_head *head)))
> +static void _rcu_barrier(struct rcu_state *rsp)
> {
> int cpu;
> unsigned long flags;
> @@ -2345,8 +2343,7 @@ static void _rcu_barrier(struct rcu_state *rsp,
> while (cpu_is_offline(cpu) && ACCESS_ONCE(rdp->qlen))
> schedule_timeout_interruptible(1);
> } else if (ACCESS_ONCE(rdp->qlen)) {
> - smp_call_function_single(cpu, rcu_barrier_func,
> - (void *)call_rcu_func, 1);
> + smp_call_function_single(cpu, rcu_barrier_func, rsp, 1);
> preempt_enable();
> } else {
> preempt_enable();
> @@ -2367,7 +2364,7 @@ static void _rcu_barrier(struct rcu_state *rsp,
> raw_spin_unlock_irqrestore(&rsp->onofflock, flags);
> atomic_inc(&rcu_barrier_cpu_count);
> smp_mb__after_atomic_inc(); /* Ensure atomic_inc() before callback. */
> - call_rcu_func(&rh, rcu_barrier_callback);
> + rsp->call(&rh, rcu_barrier_callback);
>
> /*
> * Now that we have an rcu_barrier_callback() callback on each
> @@ -2390,7 +2387,7 @@ static void _rcu_barrier(struct rcu_state *rsp,
> */
> void rcu_barrier_bh(void)
> {
> - _rcu_barrier(&rcu_bh_state, call_rcu_bh);
> + _rcu_barrier(&rcu_bh_state);
> }
> EXPORT_SYMBOL_GPL(rcu_barrier_bh);
>
> @@ -2399,7 +2396,7 @@ EXPORT_SYMBOL_GPL(rcu_barrier_bh);
> */
> void rcu_barrier_sched(void)
> {
> - _rcu_barrier(&rcu_sched_state, call_rcu_sched);
> + _rcu_barrier(&rcu_sched_state);
> }
> EXPORT_SYMBOL_GPL(rcu_barrier_sched);
>
> diff --git a/kernel/rcutree.h b/kernel/rcutree.h
> index df3c2c8..15837d7 100644
> --- a/kernel/rcutree.h
> +++ b/kernel/rcutree.h
> @@ -350,6 +350,8 @@ struct rcu_state {
> u32 levelcnt[MAX_RCU_LVLS + 1]; /* # nodes in each level. */
> u8 levelspread[RCU_NUM_LVLS]; /* kids/node in each level. */
> struct rcu_data __percpu *rda; /* pointer of percu rcu_data. */
> + void (*call)(struct rcu_head *head, /* call_rcu() flavor. */
> + void (*func)(struct rcu_head *head));
>
> /* The following fields are guarded by the root rcu_node's lock. */
>
> diff --git a/kernel/rcutree_plugin.h b/kernel/rcutree_plugin.h
> index 7cb86ae..6888706 100644
> --- a/kernel/rcutree_plugin.h
> +++ b/kernel/rcutree_plugin.h
> @@ -78,7 +78,8 @@ static void __init rcu_bootup_announce_oddness(void)
>
> #ifdef CONFIG_TREE_PREEMPT_RCU
>
> -struct rcu_state rcu_preempt_state = RCU_STATE_INITIALIZER(rcu_preempt);
> +struct rcu_state rcu_preempt_state =
> + RCU_STATE_INITIALIZER(rcu_preempt, call_rcu);
> DEFINE_PER_CPU(struct rcu_data, rcu_preempt_data);
> static struct rcu_state *rcu_state = &rcu_preempt_state;
>
> @@ -944,7 +945,7 @@ static int rcu_preempt_cpu_has_callbacks(int cpu)
> */
> void rcu_barrier(void)
> {
> - _rcu_barrier(&rcu_preempt_state, call_rcu);
> + _rcu_barrier(&rcu_preempt_state);
> }
> EXPORT_SYMBOL_GPL(rcu_barrier);
>
> --
> 1.7.8
>
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
Powered by blists - more mailing lists