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McKenney" To: linux-kernel@vger.kernel.org Cc: mingo@kernel.org, jiangshanlai@gmail.com, dipankar@in.ibm.com, akpm@linux-foundation.org, mathieu.desnoyers@efficios.com, josh@joshtriplett.org, tglx@linutronix.de, peterz@infradead.org, rostedt@goodmis.org, dhowells@redhat.com, edumazet@google.com, fweisbec@gmail.com, oleg@redhat.com, joel@joelfernandes.org, "Paul E. McKenney" Subject: [PATCH tip/core/rcu 21/22] rcu: Record ->gp_state for both phases of grace-period initialization Date: Tue, 26 Jun 2018 10:10:47 -0700 X-Mailer: git-send-email 2.17.1 In-Reply-To: <20180626002052.GA24146@linux.vnet.ibm.com> References: <20180626002052.GA24146@linux.vnet.ibm.com> X-TM-AS-GCONF: 00 x-cbid: 18062617-0060-0000-0000-00000282CDC5 X-IBM-SpamModules-Scores: X-IBM-SpamModules-Versions: BY=3.00009259; HX=3.00000241; KW=3.00000007; PH=3.00000004; SC=3.00000266; SDB=6.01052668; UDB=6.00539668; IPR=6.00830593; MB=3.00021864; MTD=3.00000008; XFM=3.00000015; UTC=2018-06-26 17:08:50 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 18062617-0061-0000-0000-000045955A2E Message-Id: <20180626171048.2181-21-paulmck@linux.vnet.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:,, definitions=2018-06-26_08:,, signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 priorityscore=1501 malwarescore=0 suspectscore=1 phishscore=0 bulkscore=0 spamscore=0 clxscore=1015 lowpriorityscore=0 mlxscore=0 impostorscore=0 mlxlogscore=928 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1806210000 definitions=main-1806260192 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Grace-period initialization first processes any recent CPU-hotplug operations, and then initializes state for the new grace period. These two phases of initialization are currently not distinguished in debug prints, but the distinction is valuable in a number of debug situations. This commit therefore introduces two new values for ->gp_state, RCU_GP_ONOFF and RCU_GP_INIT, in order to make this distinction. Signed-off-by: Paul E. McKenney --- kernel/rcu/tree.c | 2 ++ kernel/rcu/tree.h | 12 ++++++++---- 2 files changed, 10 insertions(+), 4 deletions(-) diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c index 1e87ff1154a5..9e83743ca9d9 100644 --- a/kernel/rcu/tree.c +++ b/kernel/rcu/tree.c @@ -1891,6 +1891,7 @@ static bool rcu_gp_init(struct rcu_state *rsp) * for subsequent online CPUs, and that quiescent-state forcing * will handle subsequent offline CPUs. */ + rsp->gp_state = RCU_GP_ONOFF; rcu_for_each_leaf_node(rsp, rnp) { spin_lock(&rsp->ofl_lock); raw_spin_lock_irq_rcu_node(rnp); @@ -1950,6 +1951,7 @@ static bool rcu_gp_init(struct rcu_state *rsp) * The grace period cannot complete until the initialization * process finishes, because this kthread handles both. */ + rsp->gp_state = RCU_GP_INIT; rcu_for_each_node_breadth_first(rsp, rnp) { rcu_gp_slow(rsp, gp_init_delay); raw_spin_lock_irqsave_rcu_node(rnp, flags); diff --git a/kernel/rcu/tree.h b/kernel/rcu/tree.h index f52bc059bfec..8077aff7ab40 100644 --- a/kernel/rcu/tree.h +++ b/kernel/rcu/tree.h @@ -380,16 +380,20 @@ struct rcu_state { #define RCU_GP_IDLE 0 /* Initial state and no GP in progress. */ #define RCU_GP_WAIT_GPS 1 /* Wait for grace-period start. */ #define RCU_GP_DONE_GPS 2 /* Wait done for grace-period start. */ -#define RCU_GP_WAIT_FQS 3 /* Wait for force-quiescent-state time. */ -#define RCU_GP_DOING_FQS 4 /* Wait done for force-quiescent-state time. */ -#define RCU_GP_CLEANUP 5 /* Grace-period cleanup started. */ -#define RCU_GP_CLEANED 6 /* Grace-period cleanup complete. */ +#define RCU_GP_ONOFF 3 /* Grace-period initialization hotplug. */ +#define RCU_GP_INIT 4 /* Grace-period initialization. */ +#define RCU_GP_WAIT_FQS 5 /* Wait for force-quiescent-state time. */ +#define RCU_GP_DOING_FQS 6 /* Wait done for force-quiescent-state time. */ +#define RCU_GP_CLEANUP 7 /* Grace-period cleanup started. */ +#define RCU_GP_CLEANED 8 /* Grace-period cleanup complete. */ #ifndef RCU_TREE_NONCORE static const char * const gp_state_names[] = { "RCU_GP_IDLE", "RCU_GP_WAIT_GPS", "RCU_GP_DONE_GPS", + "RCU_GP_ONOFF", + "RCU_GP_INIT", "RCU_GP_WAIT_FQS", "RCU_GP_DOING_FQS", "RCU_GP_CLEANUP", -- 2.17.1