[RFC PATCH 5/6] sched/isolation: Make HK_FLAG_DOMAIN mutable
From: Frederic Weisbecker <hidden>
Date: 2021-07-14 13:54:44
Also in:
lkml
Subsystem:
scheduler, the rest · Maintainers:
Ingo Molnar, Peter Zijlstra, Juri Lelli, Vincent Guittot, Linus Torvalds
In order to prepare supporting "isolcpus=" changes toward cpuset, provide an API to modify the "isolcpus=" cpumask passed on boot. TODO: * Propagate the change to all interested subsystems (workqueue, net, pci) * Make sure we can't concurrently change this cpumask (assert cpuset_rwsem is held). Signed-off-by: Frederic Weisbecker <redacted> Cc: Thomas Gleixner <redacted> Cc: Juri Lelli <redacted> Cc: Marcelo Tosatti <redacted> Cc: Nitesh Lal <redacted> Cc: Nicolas Saenz <redacted> Cc: Peter Zijlstra <redacted> Cc: Christoph Lameter <redacted> Cc: Tejun Heo <redacted> Cc: Zefan Li <redacted> Cc: Alex Belits <redacted> --- include/linux/sched/isolation.h | 4 ++++ kernel/sched/isolation.c | 19 +++++++++++++++++++ 2 files changed, 23 insertions(+)
diff --git a/include/linux/sched/isolation.h b/include/linux/sched/isolation.h
index cc9f393e2a70..a5960cb357d2 100644
--- a/include/linux/sched/isolation.h
+++ b/include/linux/sched/isolation.h@@ -21,6 +21,7 @@ enum hk_flags { DECLARE_STATIC_KEY_FALSE(housekeeping_overridden); extern int housekeeping_any_cpu(enum hk_flags flags); extern const struct cpumask *housekeeping_cpumask(enum hk_flags flags); +extern void housekeeping_cpumask_set(struct cpumask *mask, enum hk_flags flags); extern bool housekeeping_enabled(enum hk_flags flags); extern void housekeeping_affine(struct task_struct *t, enum hk_flags flags); extern bool housekeeping_test_cpu(int cpu, enum hk_flags flags);
@@ -38,6 +39,9 @@ static inline const struct cpumask *housekeeping_cpumask(enum hk_flags flags) return cpu_possible_mask; } +static inline void housekeeping_cpumask_set(struct cpumask *mask, + enum hk_flags flags) { } + static inline bool housekeeping_enabled(enum hk_flags flags) { return false;
diff --git a/kernel/sched/isolation.c b/kernel/sched/isolation.c
index c2bdf7e6dc39..c071433059cf 100644
--- a/kernel/sched/isolation.c
+++ b/kernel/sched/isolation.c@@ -68,7 +68,26 @@ bool housekeeping_test_cpu(int cpu, enum hk_flags flags) } EXPORT_SYMBOL_GPL(housekeeping_test_cpu); +// Only support HK_FLAG_DOMAIN for now +// TODO: propagate the changes through all interested subsystems: +// workqueues, net, pci; ... +void housekeeping_cpumask_set(struct cpumask *mask, enum hk_flags flags) +{ + /* Only HK_FLAG_DOMAIN change supported for now */ + if (WARN_ON_ONCE(flags != HK_FLAG_DOMAIN)) + return; + if (!static_key_enabled(&housekeeping_overridden.key)) { + if (cpumask_equal(mask, cpu_possible_mask)) + return; + if (WARN_ON_ONCE(!alloc_cpumask_var(&hk_domain_mask, GFP_KERNEL))) + return; + cpumask_copy(hk_domain_mask, mask); + static_branch_enable(&housekeeping_overridden); + } else { + cpumask_copy(hk_domain_mask, mask); + } +} void __init housekeeping_init(void) {
--
2.25.1