From: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
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" <paulmck@linux.vnet.ibm.com>
Subject: [PATCH tip/core/rcu 17/22] rcu: RCU_SAVE_DYNTICK code no longer ever dead
Date: Fri, 22 Jun 2012 08:17:16 -0700 [thread overview]
Message-ID: <1340378241-6458-17-git-send-email-paulmck@linux.vnet.ibm.com> (raw)
In-Reply-To: <1340378241-6458-1-git-send-email-paulmck@linux.vnet.ibm.com>
From: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Before RCU had unified idle, the RCU_SAVE_DYNTICK leg of the switch
statement in force_quiescent_state() was dead code for CONFIG_NO_HZ=n
kernel builds. With unified idle, the code is never dead. This commit
therefore removes the "if" statement designed to make gcc aware of when
the code was and was not dead.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
---
kernel/rcutree.c | 2 --
1 files changed, 0 insertions(+), 2 deletions(-)
diff --git a/kernel/rcutree.c b/kernel/rcutree.c
index 68a9d8b..1b0e441 100644
--- a/kernel/rcutree.c
+++ b/kernel/rcutree.c
@@ -1744,8 +1744,6 @@ static void force_quiescent_state(struct rcu_state *rsp, int relaxed)
break; /* grace period idle or initializing, ignore. */
case RCU_SAVE_DYNTICK:
- if (RCU_SIGNAL_INIT != RCU_SAVE_DYNTICK)
- break; /* So gcc recognizes the dead code. */
raw_spin_unlock(&rnp->lock); /* irqs remain disabled */
--
1.7.8
next prev parent reply other threads:[~2012-06-22 15:28 UTC|newest]
Thread overview: 27+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-06-22 15:16 [PATCH tip/core/rcu 0/22] v2 Improvements to rcu_barrier() and RT response on big systems Paul E. McKenney
2012-06-22 15:17 ` [PATCH tip/core/rcu 01/22] rcu: Control RCU_FANOUT_LEAF from boot-time parameter Paul E. McKenney
2012-06-22 15:17 ` [PATCH tip/core/rcu 02/22] rcu: Four-level hierarchy is no longer experimental Paul E. McKenney
2012-06-22 15:17 ` [PATCH tip/core/rcu 03/22] rcu: Size rcu_node tree from nr_cpu_ids rather than NR_CPUS Paul E. McKenney
2012-06-22 15:17 ` [PATCH tip/core/rcu 04/22] rcu: Prevent excessive line length in RCU_STATE_INITIALIZER() Paul E. McKenney
2012-06-22 15:17 ` [PATCH tip/core/rcu 05/22] rcu: Place pointer to call_rcu() in rcu_data structure Paul E. McKenney
2012-06-22 15:17 ` [PATCH tip/core/rcu 06/22] rcu: Move _rcu_barrier()'s rcu_head structures to rcu_data structures Paul E. McKenney
2012-06-22 15:17 ` [PATCH tip/core/rcu 07/22] rcu: Move rcu_barrier_cpu_count to rcu_state structure Paul E. McKenney
2012-06-22 15:17 ` [PATCH tip/core/rcu 08/22] rcu: Move rcu_barrier_completion " Paul E. McKenney
2012-06-22 15:17 ` [PATCH tip/core/rcu 09/22] rcu: Move rcu_barrier_mutex " Paul E. McKenney
2012-06-22 15:17 ` [PATCH tip/core/rcu 10/22] rcu: Remove needless initialization Paul E. McKenney
2012-06-22 15:17 ` [PATCH tip/core/rcu 11/22] rcu: Increase rcu_barrier() concurrency Paul E. McKenney
2012-06-22 15:17 ` [PATCH tip/core/rcu 12/22] rcu: Add tracing for _rcu_barrier() Paul E. McKenney
2012-06-22 15:17 ` [PATCH tip/core/rcu 13/22] rcu: Add rcu_barrier() statistics to debugfs tracing Paul E. McKenney
2012-06-22 15:17 ` [PATCH tip/core/rcu 14/22] rcu: Remove unneeded __rcu_process_callbacks() argument Paul E. McKenney
2012-06-22 15:17 ` [PATCH tip/core/rcu 15/22] rcu: Introduce for_each_rcu_flavor() and use it Paul E. McKenney
2012-06-22 15:17 ` [PATCH tip/core/rcu 16/22] rcu: Use for_each_rcu_flavor() in TREE_RCU tracing Paul E. McKenney
2012-06-22 15:17 ` Paul E. McKenney [this message]
2012-06-22 15:17 ` [PATCH tip/core/rcu 18/22] rcu: Move RCU grace-period initialization into a kthread Paul E. McKenney
2012-06-22 15:17 ` [PATCH tip/core/rcu 19/22] rcu: Allow RCU grace-period initialization to be preempted Paul E. McKenney
2012-06-22 15:17 ` [PATCH tip/core/rcu 20/22] rcu: Move RCU grace-period cleanup into kthread Paul E. McKenney
2012-06-22 15:17 ` [PATCH tip/core/rcu 21/22] rcu: Allow RCU grace-period cleanup to be preempted Paul E. McKenney
2012-06-22 15:17 ` [PATCH tip/core/rcu 22/22] rcu: Prevent offline CPUs from executing RCU core code Paul E. McKenney
2012-07-01 6:19 ` [PATCH tip/core/rcu 01/22] rcu: Control RCU_FANOUT_LEAF from boot-time parameter Rusty Russell
2012-07-01 7:17 ` Josh Triplett
2012-07-01 12:52 ` Paul E. McKenney
2012-07-01 17:45 ` Josh Triplett
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