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authorLinus Torvalds <torvalds@linux-foundation.org>2015-11-04 05:03:50 +0300
committerLinus Torvalds <torvalds@linux-foundation.org>2015-11-04 05:03:50 +0300
commit53528695ff6d8b77011bc818407c13e30914a946 (patch)
tree04acd099c5759bf6f1d728c5415f574d572c6872 /include/linux/sched.h
parentb831ef2cad979912850e34f82415c0c5d59de8cb (diff)
parente73e85f0593832aa583b252f9a16cf90ed6d30fa (diff)
downloadlinux-53528695ff6d8b77011bc818407c13e30914a946.tar.xz
Merge branch 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull scheduler changes from Ingo Molnar: "The main changes in this cycle were: - sched/fair load tracking fixes and cleanups (Byungchul Park) - Make load tracking frequency scale invariant (Dietmar Eggemann) - sched/deadline updates (Juri Lelli) - stop machine fixes, cleanups and enhancements for bugs triggered by CPU hotplug stress testing (Oleg Nesterov) - scheduler preemption code rework: remove PREEMPT_ACTIVE and related cleanups (Peter Zijlstra) - Rework the sched_info::run_delay code to fix races (Peter Zijlstra) - Optimize per entity utilization tracking (Peter Zijlstra) - ... misc other fixes, cleanups and smaller updates" * 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (57 commits) sched: Don't scan all-offline ->cpus_allowed twice if !CONFIG_CPUSETS sched: Move cpu_active() tests from stop_two_cpus() into migrate_swap_stop() sched: Start stopper early stop_machine: Kill cpu_stop_threads->setup() and cpu_stop_unpark() stop_machine: Kill smp_hotplug_thread->pre_unpark, introduce stop_machine_unpark() stop_machine: Change cpu_stop_queue_two_works() to rely on stopper->enabled stop_machine: Introduce __cpu_stop_queue_work() and cpu_stop_queue_two_works() stop_machine: Ensure that a queued callback will be called before cpu_stop_park() sched/x86: Fix typo in __switch_to() comments sched/core: Remove a parameter in the migrate_task_rq() function sched/core: Drop unlikely behind BUG_ON() sched/core: Fix task and run queue sched_info::run_delay inconsistencies sched/numa: Fix task_tick_fair() from disabling numa_balancing sched/core: Add preempt_count invariant check sched/core: More notrace annotations sched/core: Kill PREEMPT_ACTIVE sched/core, sched/x86: Kill thread_info::saved_preempt_count sched/core: Simplify preempt_count tests sched/core: Robustify preemption leak checks sched/core: Stop setting PREEMPT_ACTIVE ...
Diffstat (limited to 'include/linux/sched.h')
-rw-r--r--include/linux/sched.h36
1 files changed, 20 insertions, 16 deletions
diff --git a/include/linux/sched.h b/include/linux/sched.h
index 56667292d1e4..9e1e06c3ce05 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -599,20 +599,26 @@ struct task_cputime_atomic {
.sum_exec_runtime = ATOMIC64_INIT(0), \
}
-#ifdef CONFIG_PREEMPT_COUNT
-#define PREEMPT_DISABLED (1 + PREEMPT_ENABLED)
-#else
-#define PREEMPT_DISABLED PREEMPT_ENABLED
-#endif
+#define PREEMPT_DISABLED (PREEMPT_DISABLE_OFFSET + PREEMPT_ENABLED)
+
+/*
+ * Disable preemption until the scheduler is running -- use an unconditional
+ * value so that it also works on !PREEMPT_COUNT kernels.
+ *
+ * Reset by start_kernel()->sched_init()->init_idle()->init_idle_preempt_count().
+ */
+#define INIT_PREEMPT_COUNT PREEMPT_OFFSET
/*
- * Disable preemption until the scheduler is running.
- * Reset by start_kernel()->sched_init()->init_idle().
+ * Initial preempt_count value; reflects the preempt_count schedule invariant
+ * which states that during context switches:
*
- * We include PREEMPT_ACTIVE to avoid cond_resched() from working
- * before the scheduler is active -- see should_resched().
+ * preempt_count() == 2*PREEMPT_DISABLE_OFFSET
+ *
+ * Note: PREEMPT_DISABLE_OFFSET is 0 for !PREEMPT_COUNT kernels.
+ * Note: See finish_task_switch().
*/
-#define INIT_PREEMPT_COUNT (PREEMPT_DISABLED + PREEMPT_ACTIVE)
+#define FORK_PREEMPT_COUNT (2*PREEMPT_DISABLE_OFFSET + PREEMPT_ENABLED)
/**
* struct thread_group_cputimer - thread group interval timer counts
@@ -1142,8 +1148,6 @@ struct sched_domain_topology_level {
#endif
};
-extern struct sched_domain_topology_level *sched_domain_topology;
-
extern void set_sched_topology(struct sched_domain_topology_level *tl);
extern void wake_up_if_idle(int cpu);
@@ -1192,10 +1196,10 @@ struct load_weight {
/*
* The load_avg/util_avg accumulates an infinite geometric series.
- * 1) load_avg factors the amount of time that a sched_entity is
- * runnable on a rq into its weight. For cfs_rq, it is the aggregated
- * such weights of all runnable and blocked sched_entities.
- * 2) util_avg factors frequency scaling into the amount of time
+ * 1) load_avg factors frequency scaling into the amount of time that a
+ * sched_entity is runnable on a rq into its weight. For cfs_rq, it is the
+ * aggregated such weights of all runnable and blocked sched_entities.
+ * 2) util_avg factors frequency and cpu scaling into the amount of time
* that a sched_entity is running on a CPU, in the range [0..SCHED_LOAD_SCALE].
* For cfs_rq, it is the aggregated such times of all runnable and
* blocked sched_entities.