Messages in this thread | | | From | Alison Chaiken <> | Subject | [PATCH 0/5] handle kthread_prio kernel cmdline parameter consistently | Date | Tue, 11 Jan 2022 15:32:49 -0800 |
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When CONFIG_PREEMPT_RT=y, RCU_SOFTIRQ work is moved to dedicated rcuc per-core threads. The rcutree.kthread_prio kernel cmdline parameter controls the priority of those threads.
A provided kthread_prio kernel cmdline parameter also elevates the priority of rcuog threads, but only if they are launched from rcu_spawn_gp_kthread(), not if they are launched from rcu_spawn_one_nocb_kthread(). Fix this inconsistency.
When CONFIG_RCU_NOCB_CPU=y, an rcu_nocbs command-line parameter offloads the work of rcuc on designated cores to new rcuop threads that are not pinned to the cores whose expired grace-period timer callbacks they run. While rcuop threads have the same function as rcuc threads, their priority is not controlled by the kthread_prio parameter. Add this feature and update the documentation accordingly.
Alison Chaiken (4): RCU: move kthread_prio bounds-check to a separate function RCU: make priority of grace-period thread consistent RCU: elevate priority of offloaded callback threads RCU: update documentation regarding kthread_prio cmdline parameter
.../admin-guide/kernel-parameters.txt | 2 + kernel/rcu/tree.c | 42 +++++++++++-------- kernel/rcu/tree_nocb.h | 7 ++++ 3 files changed, 34 insertions(+), 17 deletions(-)
-- 2.32.0
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