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[94.245.46.49]) by smtp.gmail.com with ESMTPSA id u25sm3833494lfo.71.2020.04.02.05.33.03 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 02 Apr 2020 05:33:03 -0700 (PDT) From: "Uladzislau Rezki (Sony)" To: LKML , "Paul E . McKenney" , Joel Fernandes Cc: RCU , linux-mm@kvack.org, Andrew Morton , Uladzislau Rezki , Steven Rostedt , Oleksiy Avramchenko Subject: [PATCH 2/3] rcu/tree: move locking/unlocking to separate functions Date: Thu, 2 Apr 2020 14:32:52 +0200 Message-Id: <20200402123253.10382-2-urezki@gmail.com> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20200402123253.10382-1-urezki@gmail.com> References: <20200402123253.10382-1-urezki@gmail.com> MIME-Version: 1.0 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: 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) --- 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: /*