From 230ec93909f00678401cb2d63b8b95f1dea68e40 Mon Sep 17 00:00:00 2001 From: Frederic Weisbecker Date: Fri, 4 Sep 2015 15:45:06 -0700 Subject: [PATCH] smpboot: allow passing the cpumask on per-cpu thread registration It makes the registration cheaper and simpler for the smpboot per-cpu kthread users that don't need to always update the cpumask after threads creation. [sfr@canb.auug.org.au: fix for allow passing the cpumask on per-cpu thread registration] Signed-off-by: Frederic Weisbecker Reviewed-by: Chris Metcalf Reviewed-by: Thomas Gleixner Cc: Chris Metcalf Cc: Don Zickus Cc: Peter Zijlstra Cc: Ulrich Obergfell Signed-off-by: Stephen Rothwell Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/smpboot.h | 11 ++++++++++- kernel/smpboot.c | 14 +++++++++----- kernel/watchdog.c | 9 +++------ 3 files changed, 22 insertions(+), 12 deletions(-) diff --git a/include/linux/smpboot.h b/include/linux/smpboot.h index da3c593f9845..e6109a6cd8f6 100644 --- a/include/linux/smpboot.h +++ b/include/linux/smpboot.h @@ -48,7 +48,16 @@ struct smp_hotplug_thread { const char *thread_comm; }; -int smpboot_register_percpu_thread(struct smp_hotplug_thread *plug_thread); +int smpboot_register_percpu_thread_cpumask(struct smp_hotplug_thread *plug_thread, + const struct cpumask *cpumask); + +static inline int +smpboot_register_percpu_thread(struct smp_hotplug_thread *plug_thread) +{ + return smpboot_register_percpu_thread_cpumask(plug_thread, + cpu_possible_mask); +} + void smpboot_unregister_percpu_thread(struct smp_hotplug_thread *plug_thread); int smpboot_update_cpumask_percpu_thread(struct smp_hotplug_thread *plug_thread, const struct cpumask *); diff --git a/kernel/smpboot.c b/kernel/smpboot.c index 60aa858a6a07..a818cbc73e14 100644 --- a/kernel/smpboot.c +++ b/kernel/smpboot.c @@ -273,19 +273,22 @@ static void smpboot_destroy_threads(struct smp_hotplug_thread *ht) } /** - * smpboot_register_percpu_thread - Register a per_cpu thread related to hotplug + * smpboot_register_percpu_thread_cpumask - Register a per_cpu thread related + * to hotplug * @plug_thread: Hotplug thread descriptor + * @cpumask: The cpumask where threads run * * Creates and starts the threads on all online cpus. */ -int smpboot_register_percpu_thread(struct smp_hotplug_thread *plug_thread) +int smpboot_register_percpu_thread_cpumask(struct smp_hotplug_thread *plug_thread, + const struct cpumask *cpumask) { unsigned int cpu; int ret = 0; if (!alloc_cpumask_var(&plug_thread->cpumask, GFP_KERNEL)) return -ENOMEM; - cpumask_copy(plug_thread->cpumask, cpu_possible_mask); + cpumask_copy(plug_thread->cpumask, cpumask); get_online_cpus(); mutex_lock(&smpboot_threads_lock); @@ -296,7 +299,8 @@ int smpboot_register_percpu_thread(struct smp_hotplug_thread *plug_thread) free_cpumask_var(plug_thread->cpumask); goto out; } - smpboot_unpark_thread(plug_thread, cpu); + if (cpumask_test_cpu(cpu, cpumask)) + smpboot_unpark_thread(plug_thread, cpu); } list_add(&plug_thread->list, &hotplug_threads); out: @@ -304,7 +308,7 @@ int smpboot_register_percpu_thread(struct smp_hotplug_thread *plug_thread) put_online_cpus(); return ret; } -EXPORT_SYMBOL_GPL(smpboot_register_percpu_thread); +EXPORT_SYMBOL_GPL(smpboot_register_percpu_thread_cpumask); /** * smpboot_unregister_percpu_thread - Unregister a per_cpu thread related to hotplug diff --git a/kernel/watchdog.c b/kernel/watchdog.c index a6ffa43f2993..e5bb86fb0ea5 100644 --- a/kernel/watchdog.c +++ b/kernel/watchdog.c @@ -713,15 +713,12 @@ static int watchdog_enable_all_cpus(void) int err = 0; if (!watchdog_running) { - err = smpboot_register_percpu_thread(&watchdog_threads); + err = smpboot_register_percpu_thread_cpumask(&watchdog_threads, + &watchdog_cpumask); if (err) pr_err("Failed to create watchdog threads, disabled\n"); - else { - if (smpboot_update_cpumask_percpu_thread( - &watchdog_threads, &watchdog_cpumask)) - pr_err("Failed to set cpumask for watchdog threads\n"); + else watchdog_running = 1; - } } else { /* * Enable/disable the lockup detectors or