From: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
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,
"Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Subject: [PATCH tip/core/rcu 13/17] rcu: Fold rcu_eqs_enter_common() into rcu_eqs_enter()
Date: Fri, 1 Dec 2017 11:36:44 -0800 [thread overview]
Message-ID: <1512157008-22355-13-git-send-email-paulmck@linux.vnet.ibm.com> (raw)
In-Reply-To: <20171201193625.GA20681@linux.vnet.ibm.com>
There is now only one call to rcu_eqs_enter_common() and there is no other
reason to keep it separate. This commit therefore inlines it into its
sole call site, saving a few lines of code in the process.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
---
kernel/rcu/tree.c | 43 ++++++++++++++++---------------------------
1 file changed, 16 insertions(+), 27 deletions(-)
diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c
index b2ded4d436c6..5c8a5796c71f 100644
--- a/kernel/rcu/tree.c
+++ b/kernel/rcu/tree.c
@@ -749,16 +749,27 @@ cpu_needs_another_gp(struct rcu_state *rsp, struct rcu_data *rdp)
}
/*
- * rcu_eqs_enter_common - current CPU is entering an extended quiescent state
+ * Enter an RCU extended quiescent state, which can be either the
+ * idle loop or adaptive-tickless usermode execution.
*
- * Enter idle, doing appropriate accounting. The caller must have
- * disabled interrupts.
+ * We crowbar the ->dynticks_nmi_nesting field to zero to allow for
+ * the possibility of usermode upcalls having messed up our count
+ * of interrupt nesting level during the prior busy period.
*/
-static void rcu_eqs_enter_common(bool user)
+static void rcu_eqs_enter(bool user)
{
struct rcu_state *rsp;
struct rcu_data *rdp;
- struct rcu_dynticks *rdtp = this_cpu_ptr(&rcu_dynticks);
+ struct rcu_dynticks *rdtp;
+
+ rdtp = this_cpu_ptr(&rcu_dynticks);
+ WRITE_ONCE(rdtp->dynticks_nmi_nesting, 0);
+ WARN_ON_ONCE(IS_ENABLED(CONFIG_RCU_EQS_DEBUG) &&
+ rdtp->dynticks_nesting == 0);
+ if (rdtp->dynticks_nesting != 1) {
+ rdtp->dynticks_nesting--;
+ return;
+ }
lockdep_assert_irqs_disabled();
trace_rcu_dyntick(TPS("Start"), rdtp->dynticks_nesting, 0, rdtp->dynticks);
@@ -783,28 +794,6 @@ static void rcu_eqs_enter_common(bool user)
rcu_dynticks_task_enter();
}
-/*
- * Enter an RCU extended quiescent state, which can be either the
- * idle loop or adaptive-tickless usermode execution.
- *
- * We crowbar the ->dynticks_nmi_nesting field to zero to allow for
- * the possibility of usermode upcalls having messed up our count
- * of interrupt nesting level during the prior busy period.
- */
-static void rcu_eqs_enter(bool user)
-{
- struct rcu_dynticks *rdtp;
-
- rdtp = this_cpu_ptr(&rcu_dynticks);
- WRITE_ONCE(rdtp->dynticks_nmi_nesting, 0);
- WARN_ON_ONCE(IS_ENABLED(CONFIG_RCU_EQS_DEBUG) &&
- rdtp->dynticks_nesting == 0);
- if (rdtp->dynticks_nesting == 1)
- rcu_eqs_enter_common(user);
- else
- rdtp->dynticks_nesting--;
-}
-
/**
* rcu_idle_enter - inform RCU that current CPU is entering idle
*
--
2.5.2
next prev parent reply other threads:[~2017-12-01 19:37 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-12-01 19:36 [PATCH tip/core/rcu 0/17] RCU dyntick updates for v4.16 Paul E. McKenney
2017-12-01 19:36 ` [PATCH tip/core/rcu 01/17] rcu: Avoid ->dynticks_nmi_nesting store tearing Paul E. McKenney
2017-12-01 19:36 ` [PATCH tip/core/rcu 02/17] rcu: Reduce dyntick-idle state space Paul E. McKenney
2017-12-01 19:36 ` [PATCH tip/core/rcu 03/17] rcu: Move rcu_nmi_{enter,exit}() to prepare for consolidation Paul E. McKenney
2017-12-01 19:36 ` [PATCH tip/core/rcu 04/17] rcu: Clamp ->dynticks_nmi_nesting at eqs entry/exit Paul E. McKenney
2017-12-01 19:36 ` [PATCH tip/core/rcu 05/17] rcu: Define rcu_irq_{enter,exit}() in terms of rcu_nmi_{enter,exit}() Paul E. McKenney
2017-12-01 19:36 ` [PATCH tip/core/rcu 06/17] rcu: Make ->dynticks_nesting be a simple counter Paul E. McKenney
2017-12-01 19:36 ` [PATCH tip/core/rcu 07/17] rcu: Eliminate rcu_irq_enter_disabled() Paul E. McKenney
2017-12-01 19:36 ` [PATCH tip/core/rcu 08/17] rcu: Add tracing to irq/NMI dyntick-idle transitions Paul E. McKenney
2017-12-01 19:36 ` [PATCH tip/core/rcu 09/17] rcu: Shrink ->dynticks_{nmi_,}nesting from long long to long Paul E. McKenney
2017-12-01 19:36 ` [PATCH tip/core/rcu 10/17] rcu: Add ->dynticks field to rcu_dyntick trace event Paul E. McKenney
2017-12-01 19:36 ` [PATCH tip/core/rcu 11/17] rcu: Stop duplicating lockdep checks in RCU's idle-entry code Paul E. McKenney
2017-12-01 19:36 ` [PATCH tip/core/rcu 12/17] rcu: Avoid ->dynticks_nesting store tearing Paul E. McKenney
2017-12-01 19:36 ` Paul E. McKenney [this message]
2017-12-01 19:36 ` [PATCH tip/core/rcu 14/17] rcu: Fold rcu_eqs_exit_common() into rcu_eqs_exit() Paul E. McKenney
2017-12-01 19:36 ` [PATCH tip/core/rcu 15/17] rcu: Simplify rcu_eqs_{enter,exit}() non-idle task debug code Paul E. McKenney
2017-12-01 19:36 ` [PATCH tip/core/rcu 16/17] doc: Update dyntick-idle design documentation for NMI/irq consolidation Paul E. McKenney
2017-12-01 19:36 ` [PATCH tip/core/rcu 17/17] tracing, rcu: Remove no longer used trace event rcu_prep_idle Paul E. McKenney
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