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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, joel@joelfernandes.org,
	"Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Subject: [PATCH tip/core/rcu 07/27] rcu: Inline rcu_dynticks_momentary_idle() into its sole caller
Date: Mon, 25 Jun 2018 17:34:53 -0700	[thread overview]
Message-ID: <20180626003513.27812-7-paulmck@linux.vnet.ibm.com> (raw)
In-Reply-To: <20180626003448.GA26209@linux.vnet.ibm.com>

The rcu_dynticks_momentary_idle() function is invoked only from
rcu_momentary_dyntick_idle(), and neither function is particularly
large.  This commit therefore saves a few lines by inlining
rcu_dynticks_momentary_idle() into rcu_momentary_dyntick_idle().

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
---
 kernel/rcu/tree.c | 23 +++++++----------------
 1 file changed, 7 insertions(+), 16 deletions(-)

diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c
index 1ea971244512..98f51157f735 100644
--- a/kernel/rcu/tree.c
+++ b/kernel/rcu/tree.c
@@ -385,20 +385,6 @@ static bool rcu_dynticks_in_eqs_since(struct rcu_dynticks *rdtp, int snap)
 	return snap != rcu_dynticks_snap(rdtp);
 }
 
-/*
- * Do a double-increment of the ->dynticks counter to emulate a
- * momentary idle-CPU quiescent state.
- */
-static void rcu_dynticks_momentary_idle(void)
-{
-	struct rcu_dynticks *rdtp = this_cpu_ptr(&rcu_dynticks);
-	int special = atomic_add_return(2 * RCU_DYNTICK_CTRL_CTR,
-					&rdtp->dynticks);
-
-	/* It is illegal to call this from idle state. */
-	WARN_ON_ONCE(!(special & RCU_DYNTICK_CTRL_CTR));
-}
-
 /*
  * Set the special (bottom) bit of the specified CPU so that it
  * will take special action (such as flushing its TLB) on the
@@ -430,12 +416,17 @@ bool rcu_eqs_special_set(int cpu)
  *
  * We inform the RCU core by emulating a zero-duration dyntick-idle period.
  *
- * The caller must have disabled interrupts.
+ * The caller must have disabled interrupts and must not be idle.
  */
 static void rcu_momentary_dyntick_idle(void)
 {
+	struct rcu_dynticks *rdtp = this_cpu_ptr(&rcu_dynticks);
+	int special;
+
 	raw_cpu_write(rcu_dynticks.rcu_need_heavy_qs, false);
-	rcu_dynticks_momentary_idle();
+	special = atomic_add_return(2 * RCU_DYNTICK_CTRL_CTR, &rdtp->dynticks);
+	/* It is illegal to call this from idle state. */
+	WARN_ON_ONCE(!(special & RCU_DYNTICK_CTRL_CTR));
 }
 
 /*
-- 
2.17.1


  parent reply	other threads:[~2018-06-26  0:36 UTC|newest]

Thread overview: 46+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-06-26  0:34 [PATCH tip/core/rcu 0/27] Post-gp_seq miscellaneous fixes for v4.19 Paul E. McKenney
2018-06-26  0:34 ` [PATCH tip/core/rcu 01/27] rcu: Make rcu_read_unlock_special() static Paul E. McKenney
2018-06-26  0:34 ` [PATCH tip/core/rcu 02/27] rcu: Improve rcu_note_voluntary_context_switch() reporting Paul E. McKenney
2018-06-26  0:34 ` [PATCH tip/core/rcu 03/27] rcu: rcupdate.h: Get rid of Sphinx warnings at rcu_pointer_handoff() Paul E. McKenney
2018-06-26  0:34 ` [PATCH tip/core/rcu 04/27] rcu: Use pr_fmt to prefix "rcu: " to logging output Paul E. McKenney
2018-06-26  0:34 ` [PATCH tip/core/rcu 05/27] rcu: Improve RCU-tasks naming and comments Paul E. McKenney
2018-06-26  0:34 ` [PATCH tip/core/rcu 06/27] rcu: Mark task as .need_qs less aggressively Paul E. McKenney
2018-06-26 17:08   ` Peter Zijlstra
2018-06-26 18:03     ` Paul E. McKenney
2018-06-26 21:38       ` Paul E. McKenney
2018-06-26  0:34 ` Paul E. McKenney [this message]
2018-06-26  0:34 ` [PATCH tip/core/rcu 08/27] rcu: Clarify and correct the rcu_preempt_qs() header comment Paul E. McKenney
2018-06-26  0:34 ` [PATCH tip/core/rcu 09/27] rcu: Remove unused rcu_kick_nohz_cpu() function Paul E. McKenney
2018-06-26  0:34 ` [PATCH tip/core/rcu 10/27] rcu: Remove unused local variable "cpu" Paul E. McKenney
2018-06-26  0:34 ` [PATCH tip/core/rcu 11/27] rcu: Remove "inline" from panic_on_rcu_stall() and rcu_blocking_is_gp() Paul E. McKenney
2018-06-26  0:34 ` [PATCH tip/core/rcu 12/27] rcu: Remove "inline" from rcu_torture_print_module_parms() Paul E. McKenney
2018-06-26  0:34 ` [PATCH tip/core/rcu 13/27] rcu: Remove "inline" from rcu_perf_print_module_parms() Paul E. McKenney
2018-06-26  0:35 ` [PATCH tip/core/rcu 14/27] rcu: Remove __maybe_unused from rcu_cpu_has_callbacks() Paul E. McKenney
2018-06-26  0:35 ` [PATCH tip/core/rcu 15/27] rcu: Use RCU CPU stall timeout for rcu_check_gp_start_stall() Paul E. McKenney
2018-06-26  0:35 ` [PATCH tip/core/rcu 16/27] rcu: Add comment documenting how rcu_seq_snap works Paul E. McKenney
2018-06-26 17:14   ` Peter Zijlstra
2018-06-26 18:08     ` Paul E. McKenney
2018-06-26 19:21       ` Peter Zijlstra
2018-06-26 19:31         ` Paul E. McKenney
2018-06-26 20:15           ` Peter Zijlstra
2018-06-26 22:27             ` Paul E. McKenney
2018-06-26 17:30   ` Peter Zijlstra
2018-06-26 18:10     ` Paul E. McKenney
2018-06-26 19:27       ` Peter Zijlstra
2018-06-27  4:39     ` Joel Fernandes
2018-06-27 17:54       ` Paul E. McKenney
2018-06-27 18:27         ` Joel Fernandes
2018-06-27 19:11           ` Paul E. McKenney
2018-06-28  5:10           ` Joel Fernandes
2018-06-28 17:42             ` Paul E. McKenney
2018-06-26  0:35 ` [PATCH tip/core/rcu 17/27] rcu: Speed up calling of RCU tasks callbacks Paul E. McKenney
2018-06-26  0:35 ` [PATCH tip/core/rcu 18/27] rcu: Add comment to the last sleep in the rcu tasks loop Paul E. McKenney
2018-06-26  0:35 ` [PATCH tip/core/rcu 19/27] rcu: Add diagnostics for rcutorture writer stall warning Paul E. McKenney
2018-06-26  0:35 ` [PATCH tip/core/rcu 20/27] rcu: Check the range of jiffies_till_{first,next}_fqs when setting them Paul E. McKenney
2018-06-26  0:35 ` [PATCH tip/core/rcu 21/27] doc: Update synchronize_rcu() definition in whatisRCU.txt Paul E. McKenney
2018-06-26  0:35 ` [PATCH tip/core/rcu 22/27] rcu: Make rcu_seq_diff() more exact Paul E. McKenney
2018-06-26  0:35 ` [PATCH tip/core/rcu 23/27] MAINTAINERS: Update RCU, SRCU, and TORTURE-TEST entries Paul E. McKenney
2018-06-26  0:35 ` [PATCH tip/core/rcu 24/27] rcu: Print stall-warning NMI dyntick state in hexadecimal Paul E. McKenney
2018-06-26  0:35 ` [PATCH tip/core/rcu 25/27] srcu: Add grace-period number to rcutorture statistics printout Paul E. McKenney
2018-06-26  0:35 ` [PATCH tip/core/rcu 26/27] rculist: Improve documentation for list_for_each_entry_from_rcu() Paul E. McKenney
2018-06-26  0:35 ` [PATCH tip/core/rcu 27/27] rcu: Assign higher prio to RCU threads if rcutorture is built-in Paul E. McKenney

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