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,
dvhart@linux.intel.com, fweisbec@gmail.com, oleg@redhat.com,
bobby.prani@gmail.com,
"Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Subject: [PATCH v2 tip/core/rcu 06/11] rcu: Make expedited grace periods resolve stall-warning ties
Date: Wed, 9 Dec 2015 15:03:03 -0800 [thread overview]
Message-ID: <1449702188-493-6-git-send-email-paulmck@linux.vnet.ibm.com> (raw)
In-Reply-To: <20151209230243.GA32518@linux.vnet.ibm.com>
Currently, if a grace period ends just as the stall-warning timeout
fires, an empty stall warning will be printed. This is not helpful,
so this commit avoids these useless warnings by rechecking completion
after awakening in synchronize_sched_expedited_wait().
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
---
kernel/rcu/tree.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c
index 33d7e2551165..bc6b79716a86 100644
--- a/kernel/rcu/tree.c
+++ b/kernel/rcu/tree.c
@@ -3757,7 +3757,7 @@ static void synchronize_sched_expedited_wait(struct rcu_state *rsp)
rsp->expedited_wq,
sync_rcu_preempt_exp_done(rnp_root),
jiffies_stall);
- if (ret > 0)
+ if (ret > 0 || sync_rcu_preempt_exp_done(rnp_root))
return;
if (ret < 0) {
/* Hit a signal, disable CPU stall warnings. */
--
2.5.2
next prev parent reply other threads:[~2015-12-09 23:03 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-12-09 23:02 [PATCH v2 tip/core/rcu 0/11] Expedited-grace-period changes for 4.5 Paul E. McKenney
2015-12-09 23:02 ` [PATCH v2 tip/core/rcu 01/11] rcu: Short-circuit synchronize_sched_expedited() if only one CPU Paul E. McKenney
2015-12-09 23:02 ` [PATCH v2 tip/core/rcu 02/11] rcu: Clarify role of ->expmaskinitnext Paul E. McKenney
2015-12-09 23:03 ` [PATCH v2 tip/core/rcu 03/11] rcu: Move smp_mb() from rcu_seq_snap() to rcu_exp_gp_seq_snap() Paul E. McKenney
2015-12-10 20:29 ` Peter Zijlstra
2015-12-10 20:41 ` Paul E. McKenney
2015-12-09 23:03 ` [PATCH v2 tip/core/rcu 04/11] rcu: Invert sync_rcu_exp_select_cpus() "if" statement Paul E. McKenney
2015-12-09 23:03 ` [PATCH v2 tip/core/rcu 05/11] rcu: Reduce expedited GP memory contention via per-CPU variables Paul E. McKenney
2015-12-09 23:03 ` Paul E. McKenney [this message]
2015-12-09 23:03 ` [PATCH v2 tip/core/rcu 07/11] rcu: Add more diagnostics to expedited stall warning messages Paul E. McKenney
2015-12-09 23:03 ` [PATCH v2 tip/core/rcu 08/11] rcu: Add rcu_normal kernel parameter to suppress expediting Paul E. McKenney
2015-12-09 23:03 ` [PATCH v2 tip/core/rcu 09/11] rcu: Wire up rcu_end_inkernel_boot() Paul E. McKenney
2015-12-09 23:03 ` [PATCH v2 tip/core/rcu 10/11] rcu: Allow expedited grace periods to be disabled at init Paul E. McKenney
2015-12-09 23:03 ` [PATCH v2 tip/core/rcu 11/11] rcu: Remove TINY_RCU bloat from pointless boot parameters Paul E. McKenney
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