From: tip-bot for Frederic Weisbecker <tipbot@zytor.com>
To: linux-tip-commits@vger.kernel.org
Cc: frederic@kernel.org, riel@redhat.com, cmetcalf@mellanox.com,
torvalds@linux-foundation.org, cl@linux.com,
paulmck@linux.vnet.ibm.com, kernellwp@gmail.com,
mingo@kernel.org, linux-kernel@vger.kernel.org,
lcapitulino@redhat.com, tglx@linutronix.de, hpa@zytor.com,
peterz@infradead.org, efault@gmx.de
Subject: [tip:sched/core] sched/isolation: Update nohz documentation to explain tick offload
Date: Wed, 21 Feb 2018 02:38:21 -0800 [thread overview]
Message-ID: <tip-083c6eeab2cc13894618d188b854f2fc6b5b2303@git.kernel.org> (raw)
In-Reply-To: <1519186649-3242-8-git-send-email-frederic@kernel.org>
Commit-ID: 083c6eeab2cc13894618d188b854f2fc6b5b2303
Gitweb: https://git.kernel.org/tip/083c6eeab2cc13894618d188b854f2fc6b5b2303
Author: Frederic Weisbecker <frederic@kernel.org>
AuthorDate: Wed, 21 Feb 2018 05:17:29 +0100
Committer: Ingo Molnar <mingo@kernel.org>
CommitDate: Wed, 21 Feb 2018 09:49:10 +0100
sched/isolation: Update nohz documentation to explain tick offload
Update the documentation to reflect the 1Hz tick offload changes.
Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Cc: Chris Metcalf <cmetcalf@mellanox.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Luiz Capitulino <lcapitulino@redhat.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Wanpeng Li <kernellwp@gmail.com>
Link: http://lkml.kernel.org/r/1519186649-3242-8-git-send-email-frederic@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
---
Documentation/admin-guide/kernel-parameters.txt | 11 +++++++++++
1 file changed, 11 insertions(+)
diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
index 1d1d53f..50b9837 100644
--- a/Documentation/admin-guide/kernel-parameters.txt
+++ b/Documentation/admin-guide/kernel-parameters.txt
@@ -1766,6 +1766,17 @@
nohz
Disable the tick when a single task runs.
+
+ A residual 1Hz tick is offloaded to workqueues, which you
+ need to affine to housekeeping through the global
+ workqueue's affinity configured via the
+ /sys/devices/virtual/workqueue/cpumask sysfs file, or
+ by using the 'domain' flag described below.
+
+ NOTE: by default the global workqueue runs on all CPUs,
+ so to protect individual CPUs the 'cpumask' file has to
+ be configured manually after bootup.
+
domain
Isolate from the general SMP balancing and scheduling
algorithms. Note that performing domain isolation this way
prev parent reply other threads:[~2018-02-21 10:39 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-02-21 4:17 [PATCH 0/7] isolation: 1Hz residual tick offloading v7 Frederic Weisbecker
2018-02-21 4:17 ` [PATCH 1/7] sched: Rename init_rq_hrtick to hrtick_rq_init Frederic Weisbecker
2018-02-21 10:35 ` [tip:sched/core] sched/core: Rename init_rq_hrtick() to hrtick_rq_init() tip-bot for Frederic Weisbecker
2018-02-21 4:17 ` [PATCH 2/7] nohz: Convert tick_nohz_tick_stopped() to bool Frederic Weisbecker
2018-02-21 8:29 ` Thomas Gleixner
2018-02-21 10:35 ` [tip:sched/core] " tip-bot for Frederic Weisbecker
2018-02-21 4:17 ` [PATCH 3/7] nohz: Allow to check if remote CPU tick is stopped Frederic Weisbecker
2018-02-21 10:36 ` [tip:sched/core] " tip-bot for Frederic Weisbecker
2018-02-21 4:17 ` [PATCH 4/7] sched/isolation: Isolate workqueues when "nohz_full=" is set Frederic Weisbecker
2018-02-21 10:36 ` [tip:sched/core] " tip-bot for Frederic Weisbecker
2018-02-21 4:17 ` [PATCH 5/7] sched/isolation: Offload residual 1Hz scheduler tick Frederic Weisbecker
2018-02-21 10:37 ` [tip:sched/core] " tip-bot for Frederic Weisbecker
2018-02-21 4:17 ` [PATCH 6/7] sched/nohz: Remove the 1 Hz tick code Frederic Weisbecker
2018-02-21 10:37 ` [tip:sched/core] " tip-bot for Frederic Weisbecker
2018-02-21 4:17 ` [PATCH 7/7] sched/isolation: Update nohz documentation to explain tick offload Frederic Weisbecker
2018-02-21 8:30 ` Thomas Gleixner
2018-02-21 10:38 ` tip-bot for Frederic Weisbecker [this message]
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