From: "Uladzislau Rezki (Sony)" <urezki@gmail.com>
To: LKML <linux-kernel@vger.kernel.org>,
"Paul E . McKenney" <paulmck@kernel.org>,
Joel Fernandes <joel@joelfernandes.org>
Cc: RCU <rcu@vger.kernel.org>,
linux-mm@kvack.org, Andrew Morton <akpm@linux-foundation.org>,
Uladzislau Rezki <urezki@gmail.com>,
Steven Rostedt <rostedt@goodmis.org>,
Oleksiy Avramchenko <oleksiy.avramchenko@sonymobile.com>
Subject: [PATCH 2/3] rcu/tree: move locking/unlocking to separate functions
Date: Thu, 2 Apr 2020 14:32:52 +0200 [thread overview]
Message-ID: <20200402123253.10382-2-urezki@gmail.com> (raw)
In-Reply-To: <20200402123253.10382-1-urezki@gmail.com>
Introduce two helpers to lock and unlock an access to the
per-cpu "kfree_rcu_cpu" structure. The reason is to make
kvfree_call_rcu() function to be more readable.
Signed-off-by: Uladzislau Rezki (Sony) <urezki@gmail.com>
---
kernel/rcu/tree.c | 39 +++++++++++++++++++++++++--------------
1 file changed, 25 insertions(+), 14 deletions(-)
diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c
index 24f620a06219..5e26145e9ead 100644
--- a/kernel/rcu/tree.c
+++ b/kernel/rcu/tree.c
@@ -3159,6 +3159,27 @@ static inline struct rcu_head *attach_rcu_head_to_object(void *obj)
return ((struct rcu_head *) ++ptr);
}
+static inline struct kfree_rcu_cpu *
+krc_this_cpu_lock(unsigned long *flags)
+{
+ struct kfree_rcu_cpu *krcp;
+
+ local_irq_save(*flags); // For safely calling this_cpu_ptr().
+ krcp = this_cpu_ptr(&krc);
+ if (likely(krcp->initialized))
+ spin_lock(&krcp->lock);
+
+ return krcp;
+}
+
+static inline void
+krc_this_cpu_unlock(struct kfree_rcu_cpu *krcp, unsigned long flags)
+{
+ if (likely(krcp->initialized))
+ spin_unlock(&krcp->lock);
+ local_irq_restore(flags);
+}
+
/*
* Queue a request for lazy invocation of appropriate free routine after a
* grace period. Please note there are three paths are maintained, two are the
@@ -3195,10 +3216,7 @@ void kvfree_call_rcu(struct rcu_head *head, rcu_callback_t func)
ptr = (unsigned long *) func;
}
- local_irq_save(flags); // For safely calling this_cpu_ptr().
- krcp = this_cpu_ptr(&krc);
- if (krcp->initialized)
- spin_lock(&krcp->lock);
+ krcp = krc_this_cpu_lock(&flags);
// Queue the object but don't yet schedule the batch.
if (debug_rcu_head_queue(ptr)) {
@@ -3220,19 +3238,14 @@ void kvfree_call_rcu(struct rcu_head *head, rcu_callback_t func)
/* Is headless object? */
if (head == NULL) {
/* Drop the lock. */
- if (krcp->initialized)
- spin_unlock(&krcp->lock);
- local_irq_restore(flags);
+ krc_this_cpu_unlock(krcp, flags);
head = attach_rcu_head_to_object(ptr);
if (head == NULL)
goto inline_return;
/* Take it back. */
- local_irq_save(flags);
- krcp = this_cpu_ptr(&krc);
- if (krcp->initialized)
- spin_lock(&krcp->lock);
+ krcp = krc_this_cpu_lock(&flags);
/*
* Tag the headless object. Such objects have a back-pointer
@@ -3267,9 +3280,7 @@ void kvfree_call_rcu(struct rcu_head *head, rcu_callback_t func)
}
unlock_return:
- if (krcp->initialized)
- spin_unlock(&krcp->lock);
- local_irq_restore(flags);
+ krc_this_cpu_unlock(krcp, flags);
inline_return:
/*
--
2.20.1
next prev parent reply other threads:[~2020-04-02 12:33 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-04-02 12:32 [PATCH 1/3] rcu/tree: use more permissive parameters when attaching a head Uladzislau Rezki (Sony)
2020-04-02 12:32 ` Uladzislau Rezki (Sony) [this message]
2020-04-02 12:32 ` [PATCH 3/3] lib/test_vmalloc.c: introduce two new test cases Uladzislau Rezki (Sony)
2020-04-07 2:05 ` [PATCH 1/3] rcu/tree: use more permissive parameters when attaching a head Joel Fernandes
2020-04-07 2:11 ` Joel Fernandes
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