From patchwork Wed Oct 24 11:44:12 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Daniel Vetter X-Patchwork-Id: 10654553 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id BF5CC14BD for ; Wed, 24 Oct 2018 11:44:29 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id AE34E2A3C0 for ; Wed, 24 Oct 2018 11:44:29 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id A144C2A3EC; Wed, 24 Oct 2018 11:44:29 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-5.2 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI, RCVD_IN_DNSWL_MED autolearn=ham version=3.3.1 Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher DHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id 9DE9E2A44E for ; Wed, 24 Oct 2018 11:44:28 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 2F8A86E13F; Wed, 24 Oct 2018 11:44:27 +0000 (UTC) X-Original-To: intel-gfx@lists.freedesktop.org Delivered-To: intel-gfx@lists.freedesktop.org Received: from mail-ed1-x543.google.com (mail-ed1-x543.google.com [IPv6:2a00:1450:4864:20::543]) by gabe.freedesktop.org (Postfix) with ESMTPS id 6833C6E13F for ; Wed, 24 Oct 2018 11:44:26 +0000 (UTC) Received: by mail-ed1-x543.google.com with SMTP id b7-v6so4722087edd.9 for ; Wed, 24 Oct 2018 04:44:26 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=kqoYqjAgoeWD10ZaKD1hnWs5Rn+tyKx3jXzFSi0xgwA=; b=d6m6DBIHyy/OSPoNqxiAwO9HRCq9PTGfQ4WNQ70S6x389dP7P00A9X+Nr0UHDJz6B5 xfo7GG6vWdhn7RMkuneHajUHisWIolxTfdsn6B9uQ0+K+U7t8rANvIcK30dfJnMyhL+U SmCVGzb7w8m+dDUKRh1eN9FpH78kU5w/O6fjAxbopSOOc+A65+9+Qqbgzrtpf1kXfUX4 XIkv1MnGMGKh++rM9EDhK3QmhyDnFZRlkC6zfpjepcrpZv/ZPQVo2Ee6JVCu9kRRDamE tm6LZEiDrYYNHoO12mlgPQbAJ4IKGKSdBFFVC+4Xlao24Mio7SjZ+eUldiwzuX4WIODr ljnA== X-Gm-Message-State: AGRZ1gIMQRS/KrAsv2J0m8veuzYEJ7rg4WoJllKXVvXCjx2oxp4Fw+61 FdmxIKJ3Et60pURP62bZqaSX9UKLZoU= X-Google-Smtp-Source: AJdET5ek0GDBWqZ9yJ4gP6OoGZWNi5i4KI76yFvvXNj7ZgBtJDL4TPUBBPscN8oKpBUJjrOeWotPYw== X-Received: by 2002:a50:903c:: with SMTP id b57-v6mr3874470eda.174.1540381464608; Wed, 24 Oct 2018 04:44:24 -0700 (PDT) Received: from phenom.ffwll.local ([2a02:168:569e:0:3106:d637:d723:e855]) by smtp.gmail.com with ESMTPSA id b16-v6sm1381611edt.70.2018.10.24.04.44.23 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Wed, 24 Oct 2018 04:44:23 -0700 (PDT) From: Daniel Vetter To: Intel Graphics Development Date: Wed, 24 Oct 2018 13:44:12 +0200 Message-Id: <20181024114412.31093-2-daniel.vetter@ffwll.ch> X-Mailer: git-send-email 2.19.1 In-Reply-To: <20181024114412.31093-1-daniel.vetter@ffwll.ch> References: <20181024114412.31093-1-daniel.vetter@ffwll.ch> MIME-Version: 1.0 Subject: [Intel-gfx] [PATCH 2/2] kthread: finer-grained lockdep/cross-release completion X-BeenThere: intel-gfx@lists.freedesktop.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: Intel graphics driver community testing & development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: intel-gfx-bounces@lists.freedesktop.org Sender: "Intel-gfx" X-Virus-Scanned: ClamAV using ClamSMTP Since -rc1 we're hitting a bunch of lockdep splats using the new cross-release stuff around the 2 kthread completions. In all cases they are because totally independent uses of kthread are mixed up by lockdep into the same locking class, creating artificial deadlocks. Fix this by converting kthread code in the same way as e.g. alloc_workqueue already works: Use macros for the public api so we can have a callsite specific lockdep key, then pass that through the entire callchain. Due to the many entry points this is slightly tedious. Cc: Tvrtko Ursulin Cc: Marta Lofstedt Cc: Byungchul Park Cc: Ingo Molnar Cc: Peter Zijlstra Cc: Tejun Heo Cc: Kees Cook Cc: Thomas Gleixner Cc: Shaohua Li Cc: Andrew Morton Cc: Jens Axboe Cc: Daniel Vetter Cc: Greg Kroah-Hartman Cc: Jonathan Corbet Cc: Oleg Nesterov References: https://bugs.freedesktop.org/show_bug.cgi?id=103950 Signed-off-by: Daniel Vetter --- include/linux/kthread.h | 48 ++++++++++++++++++++++++----- kernel/kthread.c | 68 ++++++++++++++++++++++++++++------------- 2 files changed, 88 insertions(+), 28 deletions(-) diff --git a/include/linux/kthread.h b/include/linux/kthread.h index c1961761311d..7a9463f0be5c 100644 --- a/include/linux/kthread.h +++ b/include/linux/kthread.h @@ -6,10 +6,12 @@ #include #include -__printf(4, 5) -struct task_struct *kthread_create_on_node(int (*threadfn)(void *data), +__printf(6, 7) +struct task_struct *_kthread_create_on_node(int (*threadfn)(void *data), void *data, int node, + struct lock_class_key *exited_key, + struct lock_class_key *parked_key, const char namefmt[], ...); /** @@ -25,12 +27,27 @@ struct task_struct *kthread_create_on_node(int (*threadfn)(void *data), */ #define kthread_create(threadfn, data, namefmt, arg...) \ kthread_create_on_node(threadfn, data, NUMA_NO_NODE, namefmt, ##arg) +#define kthread_create_on_node(threadfn, data, node, namefmt, arg...) \ +({ \ + static struct lock_class_key __exited_key, __parked_key; \ + _kthread_create_on_node(threadfn, data, node, &__exited_key, \ + &__parked_key, namefmt, ##arg); \ +}) -struct task_struct *kthread_create_on_cpu(int (*threadfn)(void *data), +struct task_struct *_kthread_create_on_cpu(int (*threadfn)(void *data), void *data, unsigned int cpu, + struct lock_class_key *exited_key, + struct lock_class_key *parked_key, const char *namefmt); +#define kthread_create_on_cpu(threadfn, data, cpu, namefmt) \ +({ \ + static struct lock_class_key __exited_key, __parked_key; \ + _kthread_create_on_cpu(threadfn, data, cpu, &__exited_key,\ + &__parked_key, namefmt); \ +}) + /** * kthread_run - create and wake a thread. @@ -171,13 +188,30 @@ extern void __kthread_init_worker(struct kthread_worker *worker, int kthread_worker_fn(void *worker_ptr); -__printf(2, 3) +__printf(4, 5) struct kthread_worker * -kthread_create_worker(unsigned int flags, const char namefmt[], ...); +_kthread_create_worker(unsigned int flags, + struct lock_class_key *exited_key, + struct lock_class_key *parked_key, + const char namefmt[], ...); +#define kthread_create_worker(flags, namefmt...) \ +({ \ + static struct lock_class_key __exited_key, __parked_key; \ + _kthread_create_worker(flags, &__exited_key, &__parked_key, \ + ##namefmt); \ +}) -__printf(3, 4) struct kthread_worker * -kthread_create_worker_on_cpu(int cpu, unsigned int flags, +__printf(5, 6) struct kthread_worker * +_kthread_create_worker_on_cpu(int cpu, unsigned int flags, + struct lock_class_key *exited_key, + struct lock_class_key *parked_key, const char namefmt[], ...); +#define kthread_create_worker_on_cpu(cpu, flags, namefmt...) \ +({ \ + static struct lock_class_key __exited_key, __parked_key; \ + _kthread_create_worker_on_cpu(cpu, flags, &__exited_key, &__parked_key,\ + ##namefmt); \ +}) bool kthread_queue_work(struct kthread_worker *worker, struct kthread_work *work); diff --git a/kernel/kthread.c b/kernel/kthread.c index 087d18d771b5..64c0464a17dd 100644 --- a/kernel/kthread.c +++ b/kernel/kthread.c @@ -32,6 +32,7 @@ struct kthread_create_info int (*threadfn)(void *data); void *data; int node; + struct lock_class_key *exited_key, *parked_key; /* Result passed back to kthread_create() from kthreadd. */ struct task_struct *result; @@ -229,8 +230,15 @@ static int kthread(void *_create) } self->data = data; - init_completion(&self->exited); - init_completion(&self->parked); + lockdep_init_map_crosslock(&self->exited.map.map, + "(kthread completion)->exited", + create->exited_key, 0); + init_completion_map(&self->exited, &self->exited.map.map); + lockdep_init_map_crosslock(&self->parked.map.map, + "(kthread completion)->parked", + create->parked_key, 0); + init_completion_map(&self->parked, &self->exited.map.map); + current->vfork_done = &self->exited; /* OK, tell user we're spawned, wait for stop or wakeup */ @@ -280,9 +288,11 @@ static void create_kthread(struct kthread_create_info *create) } } -static __printf(4, 0) +static __printf(6, 0) struct task_struct *__kthread_create_on_node(int (*threadfn)(void *data), void *data, int node, + struct lock_class_key *exited_key, + struct lock_class_key *parked_key, const char namefmt[], va_list args) { @@ -297,6 +307,8 @@ struct task_struct *__kthread_create_on_node(int (*threadfn)(void *data), create->data = data; create->node = node; create->done = &done; + create->exited_key = exited_key; + create->parked_key = parked_key; spin_lock(&kthread_create_lock); list_add_tail(&create->list, &kthread_create_list); @@ -367,21 +379,24 @@ struct task_struct *__kthread_create_on_node(int (*threadfn)(void *data), * * Returns a task_struct or ERR_PTR(-ENOMEM) or ERR_PTR(-EINTR). */ -struct task_struct *kthread_create_on_node(int (*threadfn)(void *data), - void *data, int node, - const char namefmt[], - ...) +struct task_struct *_kthread_create_on_node(int (*threadfn)(void *data), + void *data, int node, + struct lock_class_key *exited_key, + struct lock_class_key *parked_key, + const char namefmt[], + ...) { struct task_struct *task; va_list args; va_start(args, namefmt); - task = __kthread_create_on_node(threadfn, data, node, namefmt, args); + task = __kthread_create_on_node(threadfn, data, node, + exited_key, parked_key, namefmt, args); va_end(args); return task; } -EXPORT_SYMBOL(kthread_create_on_node); +EXPORT_SYMBOL(_kthread_create_on_node); static void __kthread_bind_mask(struct task_struct *p, const struct cpumask *mask, long state) { @@ -435,14 +450,16 @@ EXPORT_SYMBOL(kthread_bind); * Description: This helper function creates and names a kernel thread * The thread will be woken and put into park mode. */ -struct task_struct *kthread_create_on_cpu(int (*threadfn)(void *data), +struct task_struct *_kthread_create_on_cpu(int (*threadfn)(void *data), void *data, unsigned int cpu, + struct lock_class_key *exited_key, + struct lock_class_key *parked_key, const char *namefmt) { struct task_struct *p; - p = kthread_create_on_node(threadfn, data, cpu_to_node(cpu), namefmt, - cpu); + p = _kthread_create_on_node(threadfn, data, cpu_to_node(cpu), + exited_key, parked_key, namefmt, cpu); if (IS_ERR(p)) return p; kthread_bind(p, cpu); @@ -669,8 +686,10 @@ int kthread_worker_fn(void *worker_ptr) } EXPORT_SYMBOL_GPL(kthread_worker_fn); -static __printf(3, 0) struct kthread_worker * +static __printf(5, 0) struct kthread_worker * __kthread_create_worker(int cpu, unsigned int flags, + struct lock_class_key *exited_key, + struct lock_class_key *parked_key, const char namefmt[], va_list args) { struct kthread_worker *worker; @@ -686,8 +705,8 @@ __kthread_create_worker(int cpu, unsigned int flags, if (cpu >= 0) node = cpu_to_node(cpu); - task = __kthread_create_on_node(kthread_worker_fn, worker, - node, namefmt, args); + task = __kthread_create_on_node(kthread_worker_fn, worker, node, + exited_key, parked_key, namefmt, args); if (IS_ERR(task)) goto fail_task; @@ -714,18 +733,22 @@ __kthread_create_worker(int cpu, unsigned int flags, * when the worker was SIGKILLed. */ struct kthread_worker * -kthread_create_worker(unsigned int flags, const char namefmt[], ...) +_kthread_create_worker(unsigned int flags, + struct lock_class_key *exited_key, + struct lock_class_key *parked_key, + const char namefmt[], ...) { struct kthread_worker *worker; va_list args; va_start(args, namefmt); - worker = __kthread_create_worker(-1, flags, namefmt, args); + worker = __kthread_create_worker(-1, flags, exited_key, parked_key, + namefmt, args); va_end(args); return worker; } -EXPORT_SYMBOL(kthread_create_worker); +EXPORT_SYMBOL(_kthread_create_worker); /** * kthread_create_worker_on_cpu - create a kthread worker and bind it @@ -745,19 +768,22 @@ EXPORT_SYMBOL(kthread_create_worker); * when the worker was SIGKILLed. */ struct kthread_worker * -kthread_create_worker_on_cpu(int cpu, unsigned int flags, +_kthread_create_worker_on_cpu(int cpu, unsigned int flags, + struct lock_class_key *exited_key, + struct lock_class_key *parked_key, const char namefmt[], ...) { struct kthread_worker *worker; va_list args; va_start(args, namefmt); - worker = __kthread_create_worker(cpu, flags, namefmt, args); + worker = __kthread_create_worker(cpu, flags, exited_key, parked_key, + namefmt, args); va_end(args); return worker; } -EXPORT_SYMBOL(kthread_create_worker_on_cpu); +EXPORT_SYMBOL(_kthread_create_worker_on_cpu); /* * Returns true when the work could not be queued at the moment.