From: Marcelo Tosatti <mtosatti@redhat.com>
To: linux-kernel@vger.kernel.org
Cc: Frederic Weisbecker <frederic@kernel.org>,
Peter Zijlstra <peterz@infradead.org>,
Nitesh Narayan Lal <nitesh@redhat.com>,
Peter Xu <peterx@redhat.com>,
Marcelo Tosatti <mtosatti@redhat.com>
Subject: [patch 2/2] nohz: change signal tick dependency to wakeup CPUs of member tasks
Date: Wed, 07 Oct 2020 15:01:53 -0300 [thread overview]
Message-ID: <20201007180229.765691166@redhat.com> (raw)
In-Reply-To: 20201007180151.623061463@redhat.com
Rather than waking up all nohz_full CPUs on the system, only wakeup
the target CPUs of member threads of the signal.
Reduces interruptions to nohz_full CPUs.
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Index: linux-2.6/kernel/time/tick-sched.c
===================================================================
--- linux-2.6.orig/kernel/time/tick-sched.c
+++ linux-2.6/kernel/time/tick-sched.c
@@ -398,7 +398,15 @@ EXPORT_SYMBOL_GPL(tick_nohz_dep_clear_ta
*/
void tick_nohz_dep_set_signal(struct signal_struct *sig, enum tick_dep_bits bit)
{
- tick_nohz_dep_set_all(&sig->tick_dep_mask, bit);
+ int prev;
+
+ prev = atomic_fetch_or(BIT(bit), &sig->tick_dep_mask);
+ if (!prev) {
+ rcu_read_lock();
+ for_each_thread(sig, t)
+ tick_nohz_kick_task(t);
+ rcu_read_unlock();
+ }
}
void tick_nohz_dep_clear_signal(struct signal_struct *sig, enum tick_dep_bits bit)
next prev parent reply other threads:[~2020-10-07 18:05 UTC|newest]
Thread overview: 21+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-10-07 18:01 [patch 0/2] nohz_full: only wakeup target CPUs when notifying new tick dependency (v2) Marcelo Tosatti
2020-10-07 18:01 ` [patch 1/2] nohz: only wakeup a single target cpu when kicking a task Marcelo Tosatti
2020-10-08 12:22 ` Peter Zijlstra
2020-10-08 17:54 ` Marcelo Tosatti
2020-10-08 19:54 ` Frederic Weisbecker
2020-10-13 17:13 ` Marcelo Tosatti
2020-10-14 8:33 ` Peter Zijlstra
2020-10-14 23:40 ` Frederic Weisbecker
2020-10-15 10:12 ` Peter Zijlstra
2020-10-26 14:42 ` Frederic Weisbecker
2020-10-20 18:52 ` Marcelo Tosatti
2020-10-22 12:53 ` Frederic Weisbecker
2020-10-08 14:59 ` Peter Xu
2020-10-08 15:28 ` Peter Zijlstra
2020-10-08 19:16 ` Peter Xu
2020-10-08 19:48 ` Frederic Weisbecker
2020-10-08 17:43 ` Marcelo Tosatti
2020-10-07 18:01 ` Marcelo Tosatti [this message]
2020-10-08 12:35 ` [patch 2/2] nohz: change signal tick dependency to wakeup CPUs of member tasks Peter Zijlstra
2020-10-08 18:04 ` Marcelo Tosatti
2020-10-08 19:11 [patch 0/2] nohz_full: only wakeup target CPUs when notifying new tick dependency (v3) Marcelo Tosatti
2020-10-08 19:11 ` [patch 2/2] nohz: change signal tick dependency to wakeup CPUs of member tasks Marcelo Tosatti
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