Commit-ID: 2a595721a1fa6b684c1c818f379bef834ac3d65e Gitweb: http://git.kernel.org/tip/2a595721a1fa6b684c1c818f379bef834ac3d65e Author: Srikar Dronamraju <sri...@linux.vnet.ibm.com> AuthorDate: Tue, 11 Aug 2015 21:54:21 +0530 Committer: Ingo Molnar <mi...@kernel.org> CommitDate: Sun, 13 Sep 2015 09:52:54 +0200
sched/numa: Convert sched_numa_balancing to a static_branch Variable sched_numa_balancing toggles numa_balancing feature. Hence moving from a simple read mostly variable to a more apt static_branch. Suggested-by: Peter Zijlstra <pet...@infradead.org> Signed-off-by: Srikar Dronamraju <sri...@linux.vnet.ibm.com> Signed-off-by: Peter Zijlstra (Intel) <pet...@infradead.org> Cc: Linus Torvalds <torva...@linux-foundation.org> Cc: Mel Gorman <mgor...@suse.de> Cc: Mike Galbraith <efa...@gmx.de> Cc: Rik van Riel <r...@redhat.com> Cc: Thomas Gleixner <t...@linutronix.de> Link: http://lkml.kernel.org/r/1439310261-16124-1-git-send-email-sri...@linux.vnet.ibm.com Signed-off-by: Ingo Molnar <mi...@kernel.org> --- kernel/sched/core.c | 10 +++++++--- kernel/sched/fair.c | 6 +++--- kernel/sched/sched.h | 6 +----- 3 files changed, 11 insertions(+), 11 deletions(-) diff --git a/kernel/sched/core.c b/kernel/sched/core.c index e0bd88b..b621271 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -2114,12 +2114,16 @@ static void __sched_fork(unsigned long clone_flags, struct task_struct *p) #endif /* CONFIG_NUMA_BALANCING */ } +DEFINE_STATIC_KEY_FALSE(sched_numa_balancing); + #ifdef CONFIG_NUMA_BALANCING -__read_mostly bool sched_numa_balancing; void set_numabalancing_state(bool enabled) { - sched_numa_balancing = enabled; + if (enabled) + static_branch_enable(&sched_numa_balancing); + else + static_branch_disable(&sched_numa_balancing); } #ifdef CONFIG_PROC_SYSCTL @@ -2128,7 +2132,7 @@ int sysctl_numa_balancing(struct ctl_table *table, int write, { struct ctl_table t; int err; - int state = sched_numa_balancing; + int state = static_branch_likely(&sched_numa_balancing); if (write && !capable(CAP_SYS_ADMIN)) return -EPERM; diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index e8f0828..47ece22 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -2069,7 +2069,7 @@ void task_numa_fault(int last_cpupid, int mem_node, int pages, int flags) int local = !!(flags & TNF_FAULT_LOCAL); int priv; - if (!sched_numa_balancing) + if (!static_branch_likely(&sched_numa_balancing)) return; /* for example, ksmd faulting in a user's mm */ @@ -5562,7 +5562,7 @@ static int migrate_degrades_locality(struct task_struct *p, struct lb_env *env) unsigned long src_faults, dst_faults; int src_nid, dst_nid; - if (!sched_numa_balancing) + if (!static_branch_likely(&sched_numa_balancing)) return -1; if (!p->numa_faults || !(env->sd->flags & SD_NUMA)) @@ -7874,7 +7874,7 @@ static void task_tick_fair(struct rq *rq, struct task_struct *curr, int queued) entity_tick(cfs_rq, se, queued); } - if (sched_numa_balancing) + if (!static_branch_unlikely(&sched_numa_balancing)) task_tick_numa(rq, curr); } diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h index 0d8f885..2e8530d0 100644 --- a/kernel/sched/sched.h +++ b/kernel/sched/sched.h @@ -1003,11 +1003,7 @@ extern struct static_key sched_feat_keys[__SCHED_FEAT_NR]; #define sched_feat(x) (sysctl_sched_features & (1UL << __SCHED_FEAT_##x)) #endif /* SCHED_DEBUG && HAVE_JUMP_LABEL */ -#ifdef CONFIG_NUMA_BALANCING -extern bool sched_numa_balancing; -#else -#define sched_numa_balancing (0) -#endif /* CONFIG_NUMA_BALANCING */ +extern struct static_key_false sched_numa_balancing; static inline u64 global_rt_period(void) { -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
