From: pbonzini@redhat.com (Paolo Bonzini)
Subject: [ltt-dev] [URCU RFC patch 2/3] call_rcu: use futex for wakeup scheme
Date: Wed, 08 Jun 2011 09:04:36 +0200 [thread overview]
Message-ID: <isn6u4$f1v$1@dough.gmane.org> (raw)
In-Reply-To: <20110606175029.073385695@efficios.com>
On 06/06/2011 07:46 PM, Mathieu Desnoyers wrote:
> +static void call_rcu_wait(struct call_rcu_data *crdp)
> +{
> + /* Read call_rcu list before read futex */
> + cmm_smp_mb();
> + if (uatomic_read(&crdp->futex) == -1)
> + futex_async(&crdp->futex, FUTEX_WAIT, -1,
> + NULL, NULL, 0);
> +}
> +
> +static void call_rcu_wake_up(struct call_rcu_data *crdp)
> +{
> + /* Write to call_rcu list before reading/writing futex */
> + cmm_smp_mb();
> + if (unlikely(uatomic_read(&crdp->futex) == -1)) {
> + uatomic_set(&crdp->futex, 0);
> + futex_async(&crdp->futex, FUTEX_WAKE, 1,
> + NULL, NULL, 0);
> + }
> +}
I don't see crdp->futex ever set to -1, am I missing something obvious?
Paolo
next prev parent reply other threads:[~2011-06-08 7:04 UTC|newest]
Thread overview: 26+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-06-06 17:45 [ltt-dev] [URCU RFC patch 0/3] call_rcu() performance improvements Mathieu Desnoyers
2011-06-06 17:45 ` [ltt-dev] [URCU RFC patch 1/3] call_rcu: use cpu affinity for per-cpu call_rcu threads Mathieu Desnoyers
2011-06-06 17:45 ` Mathieu Desnoyers
2011-06-06 17:45 ` Mathieu Desnoyers
2011-06-06 19:44 ` Paul E. McKenney
2011-06-06 20:47 ` Mathieu Desnoyers
2011-06-06 21:05 ` Paul E. McKenney
2011-06-06 21:25 ` Mathieu Desnoyers
2011-06-06 17:46 ` [ltt-dev] [URCU RFC patch 2/3] call_rcu: use futex for wakeup scheme Mathieu Desnoyers
2011-06-06 17:46 ` Mathieu Desnoyers
2011-06-06 17:46 ` Mathieu Desnoyers
2011-06-06 20:06 ` [ltt-dev] [rp] " Paul E. McKenney
2011-06-07 4:16 ` Mathieu Desnoyers
2011-06-08 7:04 ` Paolo Bonzini [this message]
2011-06-08 22:31 ` [ltt-dev] " Mathieu Desnoyers
[not found] ` <BLU0-SMTP38722641CF9CD185CCFFDC96620@phx.gbl>
2011-06-09 6:14 ` Paolo Bonzini
2011-06-06 17:46 ` [ltt-dev] [URCU RFC patch 3/3] call_rcu: remove delay " Mathieu Desnoyers
2011-06-06 17:46 ` Mathieu Desnoyers
2011-06-06 17:46 ` Mathieu Desnoyers
2011-06-06 19:21 ` Mathieu Desnoyers
2011-06-06 19:41 ` Paul E. McKenney
2011-06-06 21:29 ` [ltt-dev] [rp] " Phil Howard
2011-06-06 21:39 ` Paul E. McKenney
2011-06-06 22:41 ` Mathieu Desnoyers
2011-06-06 21:26 ` Phil Howard
2011-06-06 22:29 ` Mathieu Desnoyers
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