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McKenney" To: linux-kernel@vger.kernel.org Cc: mingo@elte.hu, laijs@cn.fujitsu.com, dipankar@in.ibm.com, akpm@linux-foundation.org, mathieu.desnoyers@polymtl.ca, josh@joshtriplett.org, niv@us.ibm.com, tglx@linutronix.de, peterz@infradead.org, rostedt@goodmis.org, Valdis.Kletnieks@vt.edu, dhowells@redhat.com, eric.dumazet@gmail.com, darren@dvhart.com, fweisbec@gmail.com, sbw@mit.edu, patches@linaro.org, "Paul E. McKenney" , "Paul E. McKenney" Subject: [PATCH tip/core/rcu 03/15] rcu: Properly initialize ->boost_tasks on CPU offline Date: Thu, 30 Aug 2012 11:56:16 -0700 Message-Id: <1346352988-32444-3-git-send-email-paulmck@linux.vnet.ibm.com> X-Mailer: git-send-email 1.7.8 In-Reply-To: <1346352988-32444-1-git-send-email-paulmck@linux.vnet.ibm.com> References: <20120830185607.GA32148@linux.vnet.ibm.com> <1346352988-32444-1-git-send-email-paulmck@linux.vnet.ibm.com> X-Content-Scanned: Fidelis XPS MAILER x-cbid: 12083021-7182-0000-0000-00000274C239 X-Gm-Message-State: ALoCoQmp2RKQHhiNa7/y5iaTsukxEtAXXHTur/qAxycqjCP1UK3x4sMOF90j8Fhd6wXsGXNv93tf From: "Paul E. McKenney" When rcu_preempt_offline_tasks() clears tasks from a leaf rcu_node structure, it does not NULL out the structure's ->boost_tasks field. This commit therefore fixes this issue. Signed-off-by: Paul E. McKenney Signed-off-by: Paul E. McKenney Reviewed-by: Josh Triplett --- kernel/rcutree_plugin.h | 7 ++++--- 1 files changed, 4 insertions(+), 3 deletions(-) diff --git a/kernel/rcutree_plugin.h b/kernel/rcutree_plugin.h index 7f3244c..b1b4851 100644 --- a/kernel/rcutree_plugin.h +++ b/kernel/rcutree_plugin.h @@ -584,8 +584,11 @@ static int rcu_preempt_offline_tasks(struct rcu_state *rsp, raw_spin_unlock(&rnp_root->lock); /* irqs still disabled */ } + rnp->gp_tasks = NULL; + rnp->exp_tasks = NULL; #ifdef CONFIG_RCU_BOOST - /* In case root is being boosted and leaf is not. */ + rnp->boost_tasks = NULL; + /* In case root is being boosted and leaf was not. */ raw_spin_lock(&rnp_root->lock); /* irqs already disabled */ if (rnp_root->boost_tasks != NULL && rnp_root->boost_tasks != rnp_root->gp_tasks) @@ -593,8 +596,6 @@ static int rcu_preempt_offline_tasks(struct rcu_state *rsp, raw_spin_unlock(&rnp_root->lock); /* irqs still disabled */ #endif /* #ifdef CONFIG_RCU_BOOST */ - rnp->gp_tasks = NULL; - rnp->exp_tasks = NULL; return retval; }