Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932573AbbKRN1C (ORCPT ); Wed, 18 Nov 2015 08:27:02 -0500 Received: from mx2.suse.de ([195.135.220.15]:36424 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933052AbbKRN0y (ORCPT ); Wed, 18 Nov 2015 08:26:54 -0500 From: Petr Mladek To: Andrew Morton , Oleg Nesterov , Tejun Heo , Ingo Molnar , Peter Zijlstra Cc: Steven Rostedt , "Paul E. McKenney" , Josh Triplett , Thomas Gleixner , Linus Torvalds , Jiri Kosina , Borislav Petkov , Michal Hocko , linux-mm@kvack.org, Vlastimil Babka , linux-api@vger.kernel.org, linux-kernel@vger.kernel.org, Petr Mladek Subject: [PATCH v3 11/22] kthread: Better support freezable kthread workers Date: Wed, 18 Nov 2015 14:25:16 +0100 Message-Id: <1447853127-3461-12-git-send-email-pmladek@suse.com> X-Mailer: git-send-email 1.8.5.6 In-Reply-To: <1447853127-3461-1-git-send-email-pmladek@suse.com> References: <1447853127-3461-1-git-send-email-pmladek@suse.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 4442 Lines: 135 This patch allows to make kthread worker freezable via a new @flags parameter. It will allow to avoid an init work in some kthreads. It currently does not affect the function of kthread_worker_fn() but it might help to do some optimization or fixes eventually. I currently do not know about any other use for the @flags parameter but I believe that we will want more flags in the future. Finally, I hope that it will not cause confusion with @flags member in struct kthread. Well, I guess that we will want to rework the basic kthreads implementation once all kthreads are converted into kthread workers or workqueues. It is possible that we will merge the two structures. Signed-off-by: Petr Mladek --- include/linux/kthread.h | 11 ++++++++--- kernel/kthread.c | 17 ++++++++++++----- 2 files changed, 20 insertions(+), 8 deletions(-) diff --git a/include/linux/kthread.h b/include/linux/kthread.h index f501dfeaa0e3..2dad7020047f 100644 --- a/include/linux/kthread.h +++ b/include/linux/kthread.h @@ -65,7 +65,12 @@ struct kthread_work; typedef void (*kthread_work_func_t)(struct kthread_work *work); void delayed_kthread_work_timer_fn(unsigned long __data); +enum { + KTW_FREEZABLE = 1 << 2, /* freeze during suspend */ +}; + struct kthread_worker { + unsigned int flags; spinlock_t lock; struct list_head work_list; struct task_struct *task; @@ -154,12 +159,12 @@ extern void __init_kthread_worker(struct kthread_worker *worker, int kthread_worker_fn(void *worker_ptr); -__printf(1, 2) +__printf(2, 3) struct kthread_worker * -create_kthread_worker(const char namefmt[], ...); +create_kthread_worker(unsigned int flags, const char namefmt[], ...); struct kthread_worker * -create_kthread_worker_on_cpu(int cpu, const char namefmt[]); +create_kthread_worker_on_cpu(unsigned int flags, int cpu, const char namefmt[]); bool queue_kthread_work(struct kthread_worker *worker, struct kthread_work *work); diff --git a/kernel/kthread.c b/kernel/kthread.c index 4c3b845c719e..dbd090466e2a 100644 --- a/kernel/kthread.c +++ b/kernel/kthread.c @@ -556,6 +556,7 @@ void __init_kthread_worker(struct kthread_worker *worker, const char *name, struct lock_class_key *key) { + worker->flags = 0; spin_lock_init(&worker->lock); lockdep_set_class_and_name(&worker->lock, key, name); INIT_LIST_HEAD(&worker->work_list); @@ -605,6 +606,10 @@ int kthread_worker_fn(void *worker_ptr) */ WARN_ON(worker->task && worker->task != current); worker->task = current; + + if (worker->flags & KTW_FREEZABLE) + set_freezable(); + repeat: set_current_state(TASK_INTERRUPTIBLE); /* mb paired w/ kthread_stop */ @@ -644,7 +649,8 @@ repeat: EXPORT_SYMBOL_GPL(kthread_worker_fn); static struct kthread_worker * -__create_kthread_worker(int cpu, const char namefmt[], va_list args) +__create_kthread_worker(unsigned int flags, int cpu, + const char namefmt[], va_list args) { struct kthread_worker *worker; struct task_struct *task; @@ -664,6 +670,7 @@ __create_kthread_worker(int cpu, const char namefmt[], va_list args) if (IS_ERR(task)) goto fail_task; + worker->flags = flags; worker->task = task; wake_up_process(task); return worker; @@ -682,13 +689,13 @@ fail_task: * the worker was SIGKILLed. */ struct kthread_worker * -create_kthread_worker(const char namefmt[], ...) +create_kthread_worker(unsigned int flags, const char namefmt[], ...) { struct kthread_worker *worker; va_list args; va_start(args, namefmt); - worker = __create_kthread_worker(-1, namefmt, args); + worker = __create_kthread_worker(flags, -1, namefmt, args); va_end(args); return worker; @@ -712,12 +719,12 @@ EXPORT_SYMBOL(create_kthread_worker); * ERR_PTR(-EINVAL) on invalid @cpu. */ struct kthread_worker * -create_kthread_worker_on_cpu(int cpu, const char namefmt[]) +create_kthread_worker_on_cpu(unsigned int flags, int cpu, const char namefmt[]) { if (cpu < 0 || cpu > num_possible_cpus()) return ERR_PTR(-EINVAL); - return __create_kthread_worker(cpu, namefmt, NULL); + return __create_kthread_worker(flags, cpu, namefmt, NULL); } EXPORT_SYMBOL(create_kthread_worker_on_cpu); -- 1.8.5.6 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/