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Message-Id: <20211202003858.3129628-6-paulmck@kernel.org>
Date: Wed, 1 Dec 2021 16:38:46 -0800
From: "Paul E. McKenney" <paulmck@...nel.org>
To: rcu@...r.kernel.org
Cc: linux-kernel@...r.kernel.org, kernel-team@...com, mingo@...nel.org,
jiangshanlai@...il.com, akpm@...ux-foundation.org,
mathieu.desnoyers@...icios.com, josh@...htriplett.org,
tglx@...utronix.de, peterz@...radead.org, rostedt@...dmis.org,
dhowells@...hat.com, edumazet@...gle.com, fweisbec@...il.com,
oleg@...hat.com, joel@...lfernandes.org,
"Paul E. McKenney" <paulmck@...nel.org>, Martin Lau <kafai@...com>,
Neeraj Upadhyay <neeraj.iitr10@...il.com>
Subject: [PATCH rcu 06/18] rcu-tasks: Use spin_lock_rcu_node() and friends
This commit renames the rcu_tasks_percpu structure's ->cbs_pcpu_lock
to ->lock and then uses spin_lock_rcu_node() and friends to acquire and
release this lock, preparing for upcoming commits that will spread the
grace-period process across multiple CPUs and kthreads.
[ paulmck: Apply feedback from kernel test robot. ]
Reported-by: Martin Lau <kafai@...com>
Cc: Neeraj Upadhyay <neeraj.iitr10@...il.com>
Signed-off-by: Paul E. McKenney <paulmck@...nel.org>
---
kernel/rcu/tasks.h | 32 ++++++++++++++++----------------
1 file changed, 16 insertions(+), 16 deletions(-)
diff --git a/kernel/rcu/tasks.h b/kernel/rcu/tasks.h
index 2e58d7fa2da41..e9f59a88637cf 100644
--- a/kernel/rcu/tasks.h
+++ b/kernel/rcu/tasks.h
@@ -23,11 +23,11 @@ typedef void (*postgp_func_t)(struct rcu_tasks *rtp);
/**
* struct rcu_tasks_percpu - Per-CPU component of definition for a Tasks-RCU-like mechanism.
* @cblist: Callback list.
- * @cbs_pcpu_lock: Lock protecting per-CPU callback list.
+ * @lock: Lock protecting per-CPU callback list.
*/
struct rcu_tasks_percpu {
struct rcu_segcblist cblist;
- raw_spinlock_t cbs_pcpu_lock;
+ raw_spinlock_t __private lock;
};
/**
@@ -82,7 +82,7 @@ struct rcu_tasks {
#define DEFINE_RCU_TASKS(rt_name, gp, call, n) \
static DEFINE_PER_CPU(struct rcu_tasks_percpu, rt_name ## __percpu) = { \
- .cbs_pcpu_lock = __RAW_SPIN_LOCK_UNLOCKED(rt_name ## __percpu.cbs_pcpu_lock), \
+ .lock = __RAW_SPIN_LOCK_UNLOCKED(rt_name ## __percpu.cbs_pcpu_lock), \
}; \
static struct rcu_tasks rt_name = \
{ \
@@ -177,11 +177,11 @@ static void cblist_init_generic(struct rcu_tasks *rtp)
WARN_ON_ONCE(!rtpcp);
if (cpu)
- raw_spin_lock_init(&rtpcp->cbs_pcpu_lock);
- raw_spin_lock(&rtpcp->cbs_pcpu_lock); // irqs already disabled.
+ raw_spin_lock_init(&ACCESS_PRIVATE(rtpcp, lock));
+ raw_spin_lock_rcu_node(rtpcp); // irqs already disabled.
if (rcu_segcblist_empty(&rtpcp->cblist))
rcu_segcblist_init(&rtpcp->cblist);
- raw_spin_unlock(&rtpcp->cbs_pcpu_lock); // irqs remain disabled.
+ raw_spin_unlock_rcu_node(rtpcp); // irqs remain disabled.
}
raw_spin_unlock_irqrestore(&rtp->cbs_gbl_lock, flags);
@@ -200,15 +200,15 @@ static void call_rcu_tasks_generic(struct rcu_head *rhp, rcu_callback_t func,
local_irq_save(flags);
rtpcp = per_cpu_ptr(rtp->rtpcpu,
smp_processor_id() >> READ_ONCE(rtp->percpu_enqueue_shift));
- raw_spin_lock(&rtpcp->cbs_pcpu_lock);
+ raw_spin_lock_rcu_node(rtpcp); // irqs already disabled.
if (!rcu_segcblist_is_enabled(&rtpcp->cblist)) {
- raw_spin_unlock(&rtpcp->cbs_pcpu_lock); // irqs remain disabled.
+ raw_spin_unlock_rcu_node(rtpcp); // irqs remain disabled.
cblist_init_generic(rtp);
- raw_spin_lock(&rtpcp->cbs_pcpu_lock); // irqs already disabled.
+ raw_spin_lock_rcu_node(rtpcp); // irqs already disabled.
}
needwake = rcu_segcblist_empty(&rtpcp->cblist);
rcu_segcblist_enqueue(&rtpcp->cblist, rhp);
- raw_spin_unlock_irqrestore(&rtpcp->cbs_pcpu_lock, flags);
+ raw_spin_unlock_irqrestore_rcu_node(rtpcp, flags);
/* We can't create the thread unless interrupts are enabled. */
if (needwake && READ_ONCE(rtp->kthread_ptr))
wake_up(&rtp->cbs_wq);
@@ -250,11 +250,11 @@ static int __noreturn rcu_tasks_kthread(void *arg)
set_tasks_gp_state(rtp, RTGS_WAIT_CBS);
/* Pick up any new callbacks. */
- raw_spin_lock_irqsave(&rtpcp->cbs_pcpu_lock, flags);
+ raw_spin_lock_irqsave_rcu_node(rtpcp, flags);
smp_mb__after_spinlock(); // Order updates vs. GP.
rcu_segcblist_advance(&rtpcp->cblist, rcu_seq_current(&rtp->tasks_gp_seq));
(void)rcu_segcblist_accelerate(&rtpcp->cblist, rcu_seq_snap(&rtp->tasks_gp_seq));
- raw_spin_unlock_irqrestore(&rtpcp->cbs_pcpu_lock, flags);
+ raw_spin_unlock_irqrestore_rcu_node(rtpcp, flags);
/* If there were none, wait a bit and start over. */
if (!rcu_segcblist_pend_cbs(&rtpcp->cblist)) {
@@ -277,11 +277,11 @@ static int __noreturn rcu_tasks_kthread(void *arg)
/* Invoke the callbacks. */
set_tasks_gp_state(rtp, RTGS_INVOKE_CBS);
- raw_spin_lock_irqsave(&rtpcp->cbs_pcpu_lock, flags);
+ raw_spin_lock_irqsave_rcu_node(rtpcp, flags);
smp_mb__after_spinlock(); // Order updates vs. GP.
rcu_segcblist_advance(&rtpcp->cblist, rcu_seq_current(&rtp->tasks_gp_seq));
rcu_segcblist_extract_done_cbs(&rtpcp->cblist, &rcl);
- raw_spin_unlock_irqrestore(&rtpcp->cbs_pcpu_lock, flags);
+ raw_spin_unlock_irqrestore_rcu_node(rtpcp, flags);
len = rcl.len;
for (rhp = rcu_cblist_dequeue(&rcl); rhp; rhp = rcu_cblist_dequeue(&rcl)) {
local_bh_disable();
@@ -289,10 +289,10 @@ static int __noreturn rcu_tasks_kthread(void *arg)
local_bh_enable();
cond_resched();
}
- raw_spin_lock_irqsave(&rtpcp->cbs_pcpu_lock, flags);
+ raw_spin_lock_irqsave_rcu_node(rtpcp, flags);
rcu_segcblist_add_len(&rtpcp->cblist, -len);
(void)rcu_segcblist_accelerate(&rtpcp->cblist, rcu_seq_snap(&rtp->tasks_gp_seq));
- raw_spin_unlock_irqrestore(&rtpcp->cbs_pcpu_lock, flags);
+ raw_spin_unlock_irqrestore_rcu_node(rtpcp, flags);
/* Paranoid sleep to keep this from entering a tight loop */
schedule_timeout_idle(rtp->gp_sleep);
}
--
2.31.1.189.g2e36527f23
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