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[94.245.46.61]) by smtp.gmail.com with ESMTPSA id i4sm4338061lfu.33.2021.04.14.05.12.38 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 14 Apr 2021 05:12:38 -0700 (PDT) From: "Uladzislau Rezki (Sony)" To: LKML , RCU , "Paul E . McKenney" Cc: Michal Hocko , Andrew Morton , Daniel Axtens , Frederic Weisbecker , Neeraj Upadhyay , Joel Fernandes , Peter Zijlstra , Thomas Gleixner , "Theodore Y . Ts'o" , Sebastian Andrzej Siewior , Uladzislau Rezki , Oleksiy Avramchenko Subject: [PATCH 5/6] kvfree_rcu: clear KRC_MONITOR_TODO bit once a batch is started Date: Wed, 14 Apr 2021 14:12:25 +0200 Message-Id: <20210414121226.2650-5-urezki@gmail.com> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20210414121226.2650-1-urezki@gmail.com> References: <20210414121226.2650-1-urezki@gmail.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Before attempting of starting a new batch the KRC_MONITOR_TODO bit is cleared and set back when a previous RCU batch is still in progress. Clear the KRC_MONITOR_TODO bit only when a new batch has been successfully queued, if not, it stays active anyway, thus no reason in setting it back. Please note that checking/setting this bit is protected by the krcp->lock spinlock. Signed-off-by: Uladzislau Rezki (Sony) --- kernel/rcu/tree.c | 4 +--- 1 file changed, 1 insertion(+), 3 deletions(-) diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c index da3605067cc1..012030cbe55e 100644 --- a/kernel/rcu/tree.c +++ b/kernel/rcu/tree.c @@ -3427,16 +3427,14 @@ static inline void kfree_rcu_drain_unlock(struct kfree_rcu_cpu *krcp, unsigned long flags) { // Attempt to start a new batch. - clear_bit(KRC_MONITOR_TODO, &krcp->flags); - if (queue_kfree_rcu_work(krcp)) { // Success! Our job is done here. + clear_bit(KRC_MONITOR_TODO, &krcp->flags); raw_spin_unlock_irqrestore(&krcp->lock, flags); return; } // Previous RCU batch still in progress, try again later. - set_bit(KRC_MONITOR_TODO, &krcp->flags); schedule_delayed_work(&krcp->monitor_work, KFREE_DRAIN_JIFFIES); raw_spin_unlock_irqrestore(&krcp->lock, flags); } -- 2.20.1