Commit-ID: e179f5a04ba46ee5c5439480c2bfd68c358168b7 Gitweb: https://git.kernel.org/tip/e179f5a04ba46ee5c5439480c2bfd68c358168b7 Author: Frederic Weisbecker <[email protected]> AuthorDate: Fri, 27 Oct 2017 04:42:32 +0200 Committer: Ingo Molnar <[email protected]> CommitDate: Fri, 27 Oct 2017 09:55:27 +0200
sched/isolation: Use its own static key Housekeeping code still depends on the nohz_full static key. Since we want to decouple housekeeping from NOHZ, let's create a housekeeping specific static key. It's mostly relevant for calls to is_housekeeping_cpu() from the scheduler. Signed-off-by: Frederic Weisbecker <[email protected]> Acked-by: Thomas Gleixner <[email protected]> Cc: Chris Metcalf <[email protected]> Cc: Christoph Lameter <[email protected]> Cc: Linus Torvalds <[email protected]> Cc: Luiz Capitulino <[email protected]> Cc: Mike Galbraith <[email protected]> Cc: Paul E. McKenney <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Rik van Riel <[email protected]> Cc: Wanpeng Li <[email protected]> Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Ingo Molnar <[email protected]> --- include/linux/sched/isolation.h | 3 ++- kernel/sched/isolation.c | 13 +++++++++---- 2 files changed, 11 insertions(+), 5 deletions(-) diff --git a/include/linux/sched/isolation.h b/include/linux/sched/isolation.h index ed935ff..194c586 100644 --- a/include/linux/sched/isolation.h +++ b/include/linux/sched/isolation.h @@ -6,6 +6,7 @@ #include <linux/tick.h> #ifdef CONFIG_NO_HZ_FULL +DECLARE_STATIC_KEY_FALSE(housekeeping_overriden); extern int housekeeping_any_cpu(void); extern const struct cpumask *housekeeping_cpumask(void); extern void housekeeping_affine(struct task_struct *t); @@ -31,7 +32,7 @@ static inline void housekeeping_init(void) { } static inline bool is_housekeeping_cpu(int cpu) { #ifdef CONFIG_NO_HZ_FULL - if (tick_nohz_full_enabled()) + if (static_branch_unlikely(&housekeeping_overriden)) return housekeeping_test_cpu(cpu); #endif return true; diff --git a/kernel/sched/isolation.c b/kernel/sched/isolation.c index 1644509..bb8ba19 100644 --- a/kernel/sched/isolation.c +++ b/kernel/sched/isolation.c @@ -10,12 +10,15 @@ #include <linux/tick.h> #include <linux/init.h> #include <linux/kernel.h> +#include <linux/static_key.h> +DEFINE_STATIC_KEY_FALSE(housekeeping_overriden); +EXPORT_SYMBOL_GPL(housekeeping_overriden); static cpumask_var_t housekeeping_mask; int housekeeping_any_cpu(void) { - if (tick_nohz_full_enabled()) + if (static_branch_unlikely(&housekeeping_overriden)) return cpumask_any_and(housekeeping_mask, cpu_online_mask); return smp_processor_id(); @@ -24,7 +27,7 @@ EXPORT_SYMBOL_GPL(housekeeping_any_cpu); const struct cpumask *housekeeping_cpumask(void) { - if (tick_nohz_full_enabled()) + if (static_branch_unlikely(&housekeeping_overriden)) return housekeeping_mask; return cpu_possible_mask; @@ -33,14 +36,14 @@ EXPORT_SYMBOL_GPL(housekeeping_cpumask); void housekeeping_affine(struct task_struct *t) { - if (tick_nohz_full_enabled()) + if (static_branch_unlikely(&housekeeping_overriden)) set_cpus_allowed_ptr(t, housekeeping_mask); } EXPORT_SYMBOL_GPL(housekeeping_affine); bool housekeeping_test_cpu(int cpu) { - if (tick_nohz_full_enabled()) + if (static_branch_unlikely(&housekeeping_overriden)) return cpumask_test_cpu(cpu, housekeeping_mask); return true; @@ -62,6 +65,8 @@ void __init housekeeping_init(void) cpumask_andnot(housekeeping_mask, cpu_possible_mask, tick_nohz_full_mask); + static_branch_enable(&housekeeping_overriden); + /* We need at least one CPU to handle housekeeping work */ WARN_ON_ONCE(cpumask_empty(housekeeping_mask)); }
