Commit-ID: 083c6eeab2cc13894618d188b854f2fc6b5b2303 Gitweb: https://git.kernel.org/tip/083c6eeab2cc13894618d188b854f2fc6b5b2303 Author: Frederic Weisbecker <frede...@kernel.org> AuthorDate: Wed, 21 Feb 2018 05:17:29 +0100 Committer: Ingo Molnar <mi...@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 <frede...@kernel.org> Reviewed-by: Thomas Gleixner <t...@linutronix.de> Acked-by: Peter Zijlstra <pet...@infradead.org> Cc: Chris Metcalf <cmetc...@mellanox.com> Cc: Christoph Lameter <c...@linux.com> Cc: Linus Torvalds <torva...@linux-foundation.org> Cc: Luiz Capitulino <lcapitul...@redhat.com> Cc: Mike Galbraith <efa...@gmx.de> Cc: Paul E. McKenney <paul...@linux.vnet.ibm.com> Cc: Rik van Riel <r...@redhat.com> Cc: Wanpeng Li <kernel...@gmail.com> Link: http://lkml.kernel.org/r/1519186649-3242-8-git-send-email-frede...@kernel.org Signed-off-by: Ingo Molnar <mi...@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
