From: paulmck@kernel.org
To: rcu@vger.kernel.org
Cc: linux-kernel@vger.kernel.org, kernel-team@fb.com,
mingo@kernel.org, jiangshanlai@gmail.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@kernel.org>,
Frederic Weisbecker <frederic@kernel.org>
Subject: [PATCH tip/core/rcu 20/21] rcu/nocb: Code-style nits in callback-offloading toggling
Date: Tue, 5 Jan 2021 20:48:52 -0800 [thread overview]
Message-ID: <20210106044853.20812-20-paulmck@kernel.org> (raw)
In-Reply-To: <20210106013950.GA14663@paulmck-ThinkPad-P72>
From: "Paul E. McKenney" <paulmck@kernel.org>
This commit addresses a few code-style nits in callback-offloading
toggling, including one that predates this toggling.
Cc: Frederic Weisbecker <frederic@kernel.org>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
---
kernel/rcu/rcu_segcblist.h | 19 ++++++-------------
kernel/rcu/tree_plugin.h | 10 +++++-----
2 files changed, 11 insertions(+), 18 deletions(-)
diff --git a/kernel/rcu/rcu_segcblist.h b/kernel/rcu/rcu_segcblist.h
index 3110602..9a19328 100644
--- a/kernel/rcu/rcu_segcblist.h
+++ b/kernel/rcu/rcu_segcblist.h
@@ -80,17 +80,12 @@ static inline bool rcu_segcblist_is_enabled(struct rcu_segcblist *rsclp)
return rcu_segcblist_test_flags(rsclp, SEGCBLIST_ENABLED);
}
-/* Is the specified rcu_segcblist offloaded? */
+/* Is the specified rcu_segcblist offloaded, or is SEGCBLIST_SOFTIRQ_ONLY set? */
static inline bool rcu_segcblist_is_offloaded(struct rcu_segcblist *rsclp)
{
- if (IS_ENABLED(CONFIG_RCU_NOCB_CPU)) {
- /*
- * Complete de-offloading happens only when SEGCBLIST_SOFTIRQ_ONLY
- * is set.
- */
- if (!rcu_segcblist_test_flags(rsclp, SEGCBLIST_SOFTIRQ_ONLY))
- return true;
- }
+ if (IS_ENABLED(CONFIG_RCU_NOCB_CPU) &&
+ !rcu_segcblist_test_flags(rsclp, SEGCBLIST_SOFTIRQ_ONLY))
+ return true;
return false;
}
@@ -99,10 +94,8 @@ static inline bool rcu_segcblist_completely_offloaded(struct rcu_segcblist *rscl
{
int flags = SEGCBLIST_KTHREAD_CB | SEGCBLIST_KTHREAD_GP | SEGCBLIST_OFFLOADED;
- if (IS_ENABLED(CONFIG_RCU_NOCB_CPU)) {
- if ((rsclp->flags & flags) == flags)
- return true;
- }
+ if (IS_ENABLED(CONFIG_RCU_NOCB_CPU) && (rsclp->flags & flags) == flags)
+ return true;
return false;
}
diff --git a/kernel/rcu/tree_plugin.h b/kernel/rcu/tree_plugin.h
index bc63a6b..0ad278d 100644
--- a/kernel/rcu/tree_plugin.h
+++ b/kernel/rcu/tree_plugin.h
@@ -2160,11 +2160,11 @@ static inline bool nocb_cb_wait_cond(struct rcu_data *rdp)
static void nocb_cb_wait(struct rcu_data *rdp)
{
struct rcu_segcblist *cblist = &rdp->cblist;
- struct rcu_node *rnp = rdp->mynode;
- bool needwake_state = false;
- bool needwake_gp = false;
unsigned long cur_gp_seq;
unsigned long flags;
+ bool needwake_state = false;
+ bool needwake_gp = false;
+ struct rcu_node *rnp = rdp->mynode;
local_irq_save(flags);
rcu_momentary_dyntick_idle();
@@ -2217,8 +2217,8 @@ static void nocb_cb_wait(struct rcu_data *rdp)
swait_event_interruptible_exclusive(rdp->nocb_cb_wq,
nocb_cb_wait_cond(rdp));
- /* ^^^ Ensure CB invocation follows _sleep test. */
- if (smp_load_acquire(&rdp->nocb_cb_sleep)) {
+ // VVV Ensure CB invocation follows _sleep test.
+ if (smp_load_acquire(&rdp->nocb_cb_sleep)) { // ^^^
WARN_ON(signal_pending(current));
trace_rcu_nocb_wake(rcu_state.name, rdp->cpu, TPS("WokeEmpty"));
}
--
2.9.5
next prev parent reply other threads:[~2021-01-06 4:51 UTC|newest]
Thread overview: 22+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-01-06 1:39 [PATCH tip/core/rcu 0/21] Provide runtime switching of offloaded CPUs Paul E. McKenney
2021-01-06 4:48 ` [PATCH tip/core/rcu 01/21] rcu/nocb: Turn enabled/offload states into a common flag paulmck
2021-01-06 4:48 ` [PATCH tip/core/rcu 02/21] rcu/nocb: Provide basic callback offloading state machine bits paulmck
2021-01-06 4:48 ` [PATCH tip/core/rcu 03/21] rcu/nocb: Always init segcblist on CPU up paulmck
2021-01-06 4:48 ` [PATCH tip/core/rcu 04/21] rcu/nocb: De-offloading CB kthread paulmck
2021-01-06 4:48 ` [PATCH tip/core/rcu 05/21] rcu/nocb: Don't deoffload an offline CPU with pending work paulmck
2021-01-06 4:48 ` [PATCH tip/core/rcu 06/21] rcu/nocb: De-offloading GP kthread paulmck
2021-01-06 4:48 ` [PATCH tip/core/rcu 07/21] rcu/nocb: Re-offload support paulmck
2021-01-06 4:48 ` [PATCH tip/core/rcu 08/21] rcu/nocb: Shutdown nocb timer on de-offloading paulmck
2021-01-06 4:48 ` [PATCH tip/core/rcu 09/21] rcu/nocb: Flush bypass before setting SEGCBLIST_SOFTIRQ_ONLY paulmck
2021-01-06 4:48 ` [PATCH tip/core/rcu 10/21] rcu/nocb: Set SEGCBLIST_SOFTIRQ_ONLY at the very last stage of de-offloading paulmck
2021-01-06 4:48 ` [PATCH tip/core/rcu 11/21] rcu/nocb: Only cond_resched() from actual offloaded batch processing paulmck
2021-01-06 4:48 ` [PATCH tip/core/rcu 12/21] rcu/nocb: Process batch locally as long as offloading isn't complete paulmck
2021-01-06 4:48 ` [PATCH tip/core/rcu 13/21] rcu/nocb: Locally accelerate callbacks " paulmck
2021-01-06 4:48 ` [PATCH tip/core/rcu 14/21] cpu/hotplug: Add lockdep_is_cpus_held() paulmck
2021-01-06 4:48 ` [PATCH tip/core/rcu 15/21] timer: Add timer_curr_running() paulmck
2021-01-06 4:48 ` [PATCH tip/core/rcu 16/21] rcutorture: Test runtime toggling of CPUs' callback offloading paulmck
2021-01-06 4:48 ` [PATCH tip/core/rcu 17/21] tools/rcutorture: Support nocb toggle in TREE01 paulmck
2021-01-06 4:48 ` [PATCH tip/core/rcu 18/21] rcu/nocb: Add grace period and task state to show_rcu_nocb_state() output paulmck
2021-01-06 4:48 ` [PATCH tip/core/rcu 19/21] rcu/nocb: Add nocb CB kthread list " paulmck
2021-01-06 4:48 ` paulmck [this message]
2021-01-06 4:48 ` [PATCH tip/core/rcu 21/21] rcu: Do any deferred nocb wakeups at CPU offline time paulmck
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