diff options
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/cpu.c | 74 | ||||
| -rw-r--r-- | kernel/events/core.c | 97 | ||||
| -rw-r--r-- | kernel/freezer.c | 2 | ||||
| -rw-r--r-- | kernel/power/qos.c | 3 | ||||
| -rw-r--r-- | kernel/sched.c | 2 |
5 files changed, 78 insertions, 100 deletions
diff --git a/kernel/cpu.c b/kernel/cpu.c index 12b7458..aa39dd7a 100644 --- a/kernel/cpu.c +++ b/kernel/cpu.c @@ -15,6 +15,7 @@ #include <linux/stop_machine.h> #include <linux/mutex.h> #include <linux/gfp.h> +#include <linux/suspend.h> #ifdef CONFIG_SMP /* Serializes the updates to cpu_online_mask, cpu_present_mask */ @@ -476,6 +477,79 @@ static int alloc_frozen_cpus(void) return 0; } core_initcall(alloc_frozen_cpus); + +/* + * Prevent regular CPU hotplug from racing with the freezer, by disabling CPU + * hotplug when tasks are about to be frozen. Also, don't allow the freezer + * to continue until any currently running CPU hotplug operation gets + * completed. + * To modify the 'cpu_hotplug_disabled' flag, we need to acquire the + * 'cpu_add_remove_lock'. And this same lock is also taken by the regular + * CPU hotplug path and released only after it is complete. Thus, we + * (and hence the freezer) will block here until any currently running CPU + * hotplug operation gets completed. + */ +void cpu_hotplug_disable_before_freeze(void) +{ + cpu_maps_update_begin(); + cpu_hotplug_disabled = 1; + cpu_maps_update_done(); +} + + +/* + * When tasks have been thawed, re-enable regular CPU hotplug (which had been + * disabled while beginning to freeze tasks). + */ +void cpu_hotplug_enable_after_thaw(void) +{ + cpu_maps_update_begin(); + cpu_hotplug_disabled = 0; + cpu_maps_update_done(); +} + +/* + * When callbacks for CPU hotplug notifications are being executed, we must + * ensure that the state of the system with respect to the tasks being frozen + * or not, as reported by the notification, remains unchanged *throughout the + * duration* of the execution of the callbacks. + * Hence we need to prevent the freezer from racing with regular CPU hotplug. + * + * This synchronization is implemented by mutually excluding regular CPU + * hotplug and Suspend/Hibernate call paths by hooking onto the Suspend/ + * Hibernate notifications. + */ +static int +cpu_hotplug_pm_callback(struct notifier_block *nb, + unsigned long action, void *ptr) +{ + switch (action) { + + case PM_SUSPEND_PREPARE: + case PM_HIBERNATION_PREPARE: + cpu_hotplug_disable_before_freeze(); + break; + + case PM_POST_SUSPEND: + case PM_POST_HIBERNATION: + cpu_hotplug_enable_after_thaw(); + break; + + default: + return NOTIFY_DONE; + } + + return NOTIFY_OK; +} + + +int cpu_hotplug_pm_sync_init(void) +{ + pm_notifier(cpu_hotplug_pm_callback, 0); + return 0; +} +core_initcall(cpu_hotplug_pm_sync_init); + #endif /* CONFIG_PM_SLEEP_SMP */ /** diff --git a/kernel/events/core.c b/kernel/events/core.c index 12a0287..e1253fa 100644 --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -29,7 +29,6 @@ #include <linux/hardirq.h> #include <linux/rculist.h> #include <linux/uaccess.h> -#include <linux/suspend.h> #include <linux/syscalls.h> #include <linux/anon_inodes.h> #include <linux/kernel_stat.h> @@ -6853,7 +6852,7 @@ static void __cpuinit perf_event_init_cpu(int cpu) struct swevent_htable *swhash = &per_cpu(swevent_htable, cpu); mutex_lock(&swhash->hlist_mutex); - if (swhash->hlist_refcount > 0 && !swhash->swevent_hlist) { + if (swhash->hlist_refcount > 0) { struct swevent_hlist *hlist; hlist = kzalloc_node(sizeof(*hlist), GFP_KERNEL, cpu_to_node(cpu)); @@ -6942,14 +6941,7 @@ perf_cpu_notify(struct notifier_block *self, unsigned long action, void *hcpu) { unsigned int cpu = (long)hcpu; - /* - * Ignore suspend/resume action, the perf_pm_notifier will - * take care of that. - */ - if (action & CPU_TASKS_FROZEN) - return NOTIFY_OK; - - switch (action) { + switch (action & ~CPU_TASKS_FROZEN) { case CPU_UP_PREPARE: case CPU_DOWN_FAILED: @@ -6968,90 +6960,6 @@ perf_cpu_notify(struct notifier_block *self, unsigned long action, void *hcpu) return NOTIFY_OK; } -static void perf_pm_resume_cpu(void *unused) -{ - struct perf_cpu_context *cpuctx; - struct perf_event_context *ctx; - struct pmu *pmu; - int idx; - - idx = srcu_read_lock(&pmus_srcu); - list_for_each_entry_rcu(pmu, &pmus, entry) { - cpuctx = this_cpu_ptr(pmu->pmu_cpu_context); - ctx = cpuctx->task_ctx; - - perf_ctx_lock(cpuctx, ctx); - perf_pmu_disable(cpuctx->ctx.pmu); - - cpu_ctx_sched_out(cpuctx, EVENT_ALL); - if (ctx) - ctx_sched_out(ctx, cpuctx, EVENT_ALL); - - perf_pmu_enable(cpuctx->ctx.pmu); - perf_ctx_unlock(cpuctx, ctx); - } - srcu_read_unlock(&pmus_srcu, idx); -} - -static void perf_pm_suspend_cpu(void *unused) -{ - struct perf_cpu_context *cpuctx; - struct perf_event_context *ctx; - struct pmu *pmu; - int idx; - - idx = srcu_read_lock(&pmus_srcu); - list_for_each_entry_rcu(pmu, &pmus, entry) { - cpuctx = this_cpu_ptr(pmu->pmu_cpu_context); - ctx = cpuctx->task_ctx; - - perf_ctx_lock(cpuctx, ctx); - perf_pmu_disable(cpuctx->ctx.pmu); - - perf_event_sched_in(cpuctx, ctx, current); - - perf_pmu_enable(cpuctx->ctx.pmu); - perf_ctx_unlock(cpuctx, ctx); - } - srcu_read_unlock(&pmus_srcu, idx); -} - -static int perf_resume(void) -{ - get_online_cpus(); - smp_call_function(perf_pm_resume_cpu, NULL, 1); - put_online_cpus(); - - return NOTIFY_OK; -} - -static int perf_suspend(void) -{ - get_online_cpus(); - smp_call_function(perf_pm_suspend_cpu, NULL, 1); - put_online_cpus(); - - return NOTIFY_OK; -} - -static int perf_pm(struct notifier_block *self, unsigned long action, void *ptr) -{ - switch (action) { - case PM_POST_HIBERNATION: - case PM_POST_SUSPEND: - return perf_resume(); - case PM_HIBERNATION_PREPARE: - case PM_SUSPEND_PREPARE: - return perf_suspend(); - default: - return NOTIFY_DONE; - } -} - -static struct notifier_block perf_pm_notifier = { - .notifier_call = perf_pm, -}; - void __init perf_event_init(void) { int ret; @@ -7066,7 +6974,6 @@ void __init perf_event_init(void) perf_tp_register(); perf_cpu_notifier(perf_cpu_notify); register_reboot_notifier(&perf_reboot_notifier); - register_pm_notifier(&perf_pm_notifier); ret = init_hw_breakpoint(); WARN(ret, "hw_breakpoint initialization failed with: %d", ret); diff --git a/kernel/freezer.c b/kernel/freezer.c index 66a594e..7b01de98 100644 --- a/kernel/freezer.c +++ b/kernel/freezer.c @@ -67,7 +67,7 @@ static void fake_signal_wake_up(struct task_struct *p) unsigned long flags; spin_lock_irqsave(&p->sighand->siglock, flags); - signal_wake_up(p, 1); + signal_wake_up(p, 0); spin_unlock_irqrestore(&p->sighand->siglock, flags); } diff --git a/kernel/power/qos.c b/kernel/power/qos.c index 1c1797d..5167d99 100644 --- a/kernel/power/qos.c +++ b/kernel/power/qos.c @@ -386,8 +386,7 @@ static int pm_qos_power_open(struct inode *inode, struct file *filp) pm_qos_add_request(req, pm_qos_class, PM_QOS_DEFAULT_VALUE); filp->private_data = req; - if (filp->private_data) - return 0; + return 0; } return -EPERM; } diff --git a/kernel/sched.c b/kernel/sched.c index d87c6e5..0e9344a 100644 --- a/kernel/sched.c +++ b/kernel/sched.c @@ -7087,8 +7087,6 @@ static int __init isolated_cpu_setup(char *str) __setup("isolcpus=", isolated_cpu_setup); -#define SD_NODES_PER_DOMAIN 16 - #ifdef CONFIG_NUMA /** |
