Revert "cpuset: Make cpuset hotplug synchronous" (2b729fe7) · Commits · 戴 / test

include/linux/cpuset.h

+3 −0

Original line number	Diff line number	Diff line
		@@ -54,6 +54,7 @@ extern int cpuset_init(void);
		extern void cpuset_init_smp(void);
		extern void cpuset_force_rebuild(void);
		extern void cpuset_update_active_cpus(void);
		extern void cpuset_wait_for_hotplug(void);
		extern void cpuset_read_lock(void);
		extern void cpuset_read_unlock(void);
		extern void cpuset_cpus_allowed(struct task_struct p, struct cpumask mask);
		@@ -175,6 +176,8 @@ static inline void cpuset_update_active_cpus(void)
		partition_sched_domains(1, NULL, NULL);
		}

		static inline void cpuset_wait_for_hotplug(void) { }

		static inline void cpuset_read_lock(void) { }
		static inline void cpuset_read_unlock(void) { }

kernel/cgroup/cpuset.c

+12 −19

Original line number	Diff line number	Diff line
		@@ -3101,7 +3101,7 @@ update_tasks:
		}

		/**
		* cpuset_hotplug - handle CPU/memory hotunplug for a cpuset
		* cpuset_hotplug_workfn - handle CPU/memory hotunplug for a cpuset
		*
		* This function is called after either CPU or memory configuration has
		* changed and updates cpuset accordingly. The top_cpuset is always
		@@ -3116,7 +3116,7 @@ update_tasks:
		* Note that CPU offlining during suspend is ignored. We don't modify
		* cpusets across suspend/resume cycles at all.
		*/
		static void cpuset_hotplug(bool use_cpu_hp_lock)
		static void cpuset_hotplug_workfn(struct work_struct *work)
		{
		static cpumask_t new_cpus;
		static nodemask_t new_mems;
		@@ -3201,32 +3201,25 @@ static void cpuset_hotplug(bool use_cpu_hp_lock)
		/* rebuild sched domains if cpus_allowed has changed */
		if (cpus_updated \|\| force_rebuild) {
		force_rebuild = false;
		if (use_cpu_hp_lock)
		rebuild_sched_domains();
		else {
		/* Acquiring cpu_hotplug_lock is not required.
		* When cpuset_hotplug() is called in hotplug path,
		* cpu_hotplug_lock is held by the hotplug context
		* which is waiting for cpuhp_thread_fun to indicate
		* completion of callback.
		*/
		percpu_down_write(&cpuset_rwsem);
		rebuild_sched_domains_locked();
		percpu_up_write(&cpuset_rwsem);
		}
		}

		free_cpumasks(NULL, ptmp);
		}

		static void cpuset_hotplug_workfn(struct work_struct *work)
		void cpuset_update_active_cpus(void)
		{
		cpuset_hotplug(true);
		/*
		* We're inside cpu hotplug critical region which usually nests
		* inside cgroup synchronization. Bounce actual hotplug processing
		* to a work item to avoid reverse locking order.
		*/
		schedule_work(&cpuset_hotplug_work);
		}

		void cpuset_update_active_cpus(void)
		void cpuset_wait_for_hotplug(void)
		{
		cpuset_hotplug(false);
		flush_work(&cpuset_hotplug_work);
		}

		/*

kernel/power/process.c

+2 −0

Original line number	Diff line number	Diff line
		@@ -204,6 +204,8 @@ void thaw_processes(void)
		__usermodehelper_set_disable_depth(UMH_FREEZING);
		thaw_workqueues();

		cpuset_wait_for_hotplug();

		read_lock(&tasklist_lock);
		for_each_process_thread(g, p) {
		/* No other threads should have PF_SUSPEND_TASK set */

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