Commit-ID: a8269e3baec363b58348208719f08c9c313b1bdf Gitweb: https://git.kernel.org/tip/a8269e3baec363b58348208719f08c9c313b1bdf Author: Frederic Weisbecker <frede...@kernel.org> AuthorDate: Tue, 24 Oct 2017 15:06:54 +0200 Committer: Ingo Molnar <mi...@kernel.org> CommitDate: Tue, 24 Oct 2017 15:20:14 +0200
housekeeping: Use its own static key Housekeeping code still depends on nohz_full static key. Since we want to decouple housekeeping from nohz, let's create a housekeeping own static key. It's mostly relevant for calls to is_housekeeping_cpu() from the scheduler. Signed-off-by: Frederic Weisbecker <frede...@kernel.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: Peter Zijlstra <pet...@infradead.org> Cc: Rik van Riel <r...@redhat.com> Cc: Thomas Gleixner <t...@linutronix.de> Cc: Wanpeng Li <kernel...@gmail.com> Link: http://lkml.kernel.org/r/1508850421-10058-6-git-send-email-frede...@kernel.org Signed-off-by: Ingo Molnar <mi...@kernel.org> --- include/linux/housekeeping.h | 3 ++- kernel/housekeeping.c | 14 +++++++++----- 2 files changed, 11 insertions(+), 6 deletions(-) diff --git a/include/linux/housekeeping.h b/include/linux/housekeeping.h index 31a1401..cbe8d63 100644 --- a/include/linux/housekeeping.h +++ b/include/linux/housekeeping.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/housekeeping.c b/kernel/housekeeping.c index 0e70dc8..272c344 100644 --- a/kernel/housekeeping.c +++ b/kernel/housekeeping.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(); @@ -23,7 +26,7 @@ int housekeeping_any_cpu(void) const struct cpumask *housekeeping_cpumask(void) { - if (tick_nohz_full_enabled()) + if (static_branch_unlikely(&housekeeping_overriden)) return housekeeping_mask; return cpu_possible_mask; @@ -31,19 +34,18 @@ const struct cpumask *housekeeping_cpumask(void) 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); } 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; } - void __init housekeeping_init(void) { if (!tick_nohz_full_enabled()) @@ -59,6 +61,8 @@ 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)); }
