From 8bb7844286fb8c9fce6f65d8288aeb09d03a5e0d Mon Sep 17 00:00:00 2001 From: "Rafael J. Wysocki" Date: Wed, 9 May 2007 02:35:10 -0700 Subject: Add suspend-related notifications for CPU hotplug Since nonboot CPUs are now disabled after tasks and devices have been frozen and the CPU hotplug infrastructure is used for this purpose, we need special CPU hotplug notifications that will help the CPU-hotplug-aware subsystems distinguish normal CPU hotplug events from CPU hotplug events related to a system-wide suspend or resume operation in progress. This patch introduces such notifications and causes them to be used during suspend and resume transitions. It also changes all of the CPU-hotplug-aware subsystems to take these notifications into consideration (for now they are handled in the same way as the corresponding "normal" ones). [oleg@tv-sign.ru: cleanups] Signed-off-by: Rafael J. Wysocki Cc: Gautham R Shenoy Cc: Pavel Machek Signed-off-by: Oleg Nesterov Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- kernel/cpu.c | 34 ++++++++++++++++++---------------- 1 file changed, 18 insertions(+), 16 deletions(-) (limited to 'kernel/cpu.c') diff --git a/kernel/cpu.c b/kernel/cpu.c index 28cb6c7..369d289 100644 --- a/kernel/cpu.c +++ b/kernel/cpu.c @@ -120,12 +120,13 @@ static int take_cpu_down(void *unused) } /* Requires cpu_add_remove_lock to be held */ -static int _cpu_down(unsigned int cpu) +static int _cpu_down(unsigned int cpu, int tasks_frozen) { int err, nr_calls = 0; struct task_struct *p; cpumask_t old_allowed, tmp; void *hcpu = (void *)(long)cpu; + unsigned long mod = tasks_frozen ? CPU_TASKS_FROZEN : 0; if (num_online_cpus() == 1) return -EBUSY; @@ -134,11 +135,11 @@ static int _cpu_down(unsigned int cpu) return -EINVAL; raw_notifier_call_chain(&cpu_chain, CPU_LOCK_ACQUIRE, hcpu); - err = __raw_notifier_call_chain(&cpu_chain, CPU_DOWN_PREPARE, + err = __raw_notifier_call_chain(&cpu_chain, CPU_DOWN_PREPARE | mod, hcpu, -1, &nr_calls); if (err == NOTIFY_BAD) { - __raw_notifier_call_chain(&cpu_chain, CPU_DOWN_FAILED, hcpu, - nr_calls, NULL); + __raw_notifier_call_chain(&cpu_chain, CPU_DOWN_FAILED | mod, + hcpu, nr_calls, NULL); printk("%s: attempt to take down CPU %u failed\n", __FUNCTION__, cpu); err = -EINVAL; @@ -157,7 +158,7 @@ static int _cpu_down(unsigned int cpu) if (IS_ERR(p) || cpu_online(cpu)) { /* CPU didn't die: tell everyone. Can't complain. */ - if (raw_notifier_call_chain(&cpu_chain, CPU_DOWN_FAILED, + if (raw_notifier_call_chain(&cpu_chain, CPU_DOWN_FAILED | mod, hcpu) == NOTIFY_BAD) BUG(); @@ -176,7 +177,8 @@ static int _cpu_down(unsigned int cpu) __cpu_die(cpu); /* CPU is completely dead: tell everyone. Too late to complain. */ - if (raw_notifier_call_chain(&cpu_chain, CPU_DEAD, hcpu) == NOTIFY_BAD) + if (raw_notifier_call_chain(&cpu_chain, CPU_DEAD | mod, + hcpu) == NOTIFY_BAD) BUG(); check_for_tasks(cpu); @@ -186,8 +188,7 @@ out_thread: out_allowed: set_cpus_allowed(current, old_allowed); out_release: - raw_notifier_call_chain(&cpu_chain, CPU_LOCK_RELEASE, - (void *)(long)cpu); + raw_notifier_call_chain(&cpu_chain, CPU_LOCK_RELEASE, hcpu); return err; } @@ -199,7 +200,7 @@ int cpu_down(unsigned int cpu) if (cpu_hotplug_disabled) err = -EBUSY; else - err = _cpu_down(cpu); + err = _cpu_down(cpu, 0); mutex_unlock(&cpu_add_remove_lock); return err; @@ -207,16 +208,17 @@ int cpu_down(unsigned int cpu) #endif /*CONFIG_HOTPLUG_CPU*/ /* Requires cpu_add_remove_lock to be held */ -static int __cpuinit _cpu_up(unsigned int cpu) +static int __cpuinit _cpu_up(unsigned int cpu, int tasks_frozen) { int ret, nr_calls = 0; void *hcpu = (void *)(long)cpu; + unsigned long mod = tasks_frozen ? CPU_TASKS_FROZEN : 0; if (cpu_online(cpu) || !cpu_present(cpu)) return -EINVAL; raw_notifier_call_chain(&cpu_chain, CPU_LOCK_ACQUIRE, hcpu); - ret = __raw_notifier_call_chain(&cpu_chain, CPU_UP_PREPARE, hcpu, + ret = __raw_notifier_call_chain(&cpu_chain, CPU_UP_PREPARE | mod, hcpu, -1, &nr_calls); if (ret == NOTIFY_BAD) { printk("%s: attempt to bring up CPU %u failed\n", @@ -234,12 +236,12 @@ static int __cpuinit _cpu_up(unsigned int cpu) BUG_ON(!cpu_online(cpu)); /* Now call notifier in preparation. */ - raw_notifier_call_chain(&cpu_chain, CPU_ONLINE, hcpu); + raw_notifier_call_chain(&cpu_chain, CPU_ONLINE | mod, hcpu); out_notify: if (ret != 0) __raw_notifier_call_chain(&cpu_chain, - CPU_UP_CANCELED, hcpu, nr_calls, NULL); + CPU_UP_CANCELED | mod, hcpu, nr_calls, NULL); raw_notifier_call_chain(&cpu_chain, CPU_LOCK_RELEASE, hcpu); return ret; @@ -253,7 +255,7 @@ int __cpuinit cpu_up(unsigned int cpu) if (cpu_hotplug_disabled) err = -EBUSY; else - err = _cpu_up(cpu); + err = _cpu_up(cpu, 0); mutex_unlock(&cpu_add_remove_lock); return err; @@ -283,7 +285,7 @@ int disable_nonboot_cpus(void) for_each_online_cpu(cpu) { if (cpu == first_cpu) continue; - error = _cpu_down(cpu); + error = _cpu_down(cpu, 1); if (!error) { cpu_set(cpu, frozen_cpus); printk("CPU%d is down\n", cpu); @@ -318,7 +320,7 @@ void enable_nonboot_cpus(void) suspend_cpu_hotplug = 1; printk("Enabling non-boot CPUs ...\n"); for_each_cpu_mask(cpu, frozen_cpus) { - error = _cpu_up(cpu); + error = _cpu_up(cpu, 1); if (!error) { printk("CPU%d is up\n", cpu); continue; -- cgit v1.1