From 286f3a8af7f620dac84f20de5f7ad6542f447ace Mon Sep 17 00:00:00 2001 From: Chris Friesen Date: Tue, 24 Nov 2015 16:27:29 -0500 Subject: [PATCH 04/10] Affine irqs and workqueues with kthread_cpus If the kthread_cpus boot arg is set it means we want to affine kernel threads to the specified CPU mask as much as possible in order to avoid doing work on other CPUs. In this commit we extend the meaning of that boot arg to also apply to the CPU affinity of unbound and ordered workqueues. We also use the kthread_cpus value to determine the default irq affinity. Specifically, as long as the previously-calculated irq affinity intersects with the kthread_cpus affinity then we'll use the intersection of the two as the default irq affinity. Signed-off-by: Chris Friesen [VT: replacing spaces with tabs. Performed tests] Signed-off-by: Vu Tran Signed-off-by: Jim Somerville Signed-off-by: Zhang Zhiguo Signed-off-by: Jiping Ma --- kernel/irq/manage.c | 7 +++++++ kernel/workqueue.c | 4 ++++ 2 files changed, 11 insertions(+) diff --git a/kernel/irq/manage.c b/kernel/irq/manage.c index 79dc02b956dc..420b5ce0bf89 100644 --- a/kernel/irq/manage.c +++ b/kernel/irq/manage.c @@ -515,6 +515,13 @@ int irq_setup_affinity(struct irq_desc *desc) if (cpumask_intersects(&mask, nodemask)) cpumask_and(&mask, &mask, nodemask); } + + /* This will narrow down the affinity further if we've specified + * a reduced cpu_kthread_mask in the boot args. + */ + if (cpumask_intersects(&mask, cpu_kthread_mask)) + cpumask_and(&mask, &mask, cpu_kthread_mask); + ret = irq_do_set_affinity(&desc->irq_data, &mask, false); raw_spin_unlock(&mask_lock); return ret; diff --git a/kernel/workqueue.c b/kernel/workqueue.c index 1e2ca744dadb..b854874d0518 100644 --- a/kernel/workqueue.c +++ b/kernel/workqueue.c @@ -5956,6 +5956,8 @@ void __init workqueue_init_early(void) BUG_ON(!(attrs = alloc_workqueue_attrs())); attrs->nice = std_nice[i]; + /* If we've specified a kthread mask apply it here too. */ + cpumask_copy(attrs->cpumask, cpu_kthread_mask); unbound_std_wq_attrs[i] = attrs; /* @@ -5966,6 +5968,8 @@ void __init workqueue_init_early(void) BUG_ON(!(attrs = alloc_workqueue_attrs())); attrs->nice = std_nice[i]; attrs->no_numa = true; + /* If we've specified a kthread mask apply it here too. */ + cpumask_copy(attrs->cpumask, cpu_kthread_mask); ordered_wq_attrs[i] = attrs; } -- 2.29.2