From patchwork Fri Mar 20 08:55:25 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Davidlohr Bueso X-Patchwork-Id: 11448617 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 84E6F1392 for ; Fri, 20 Mar 2020 08:56:47 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 5FCF220767 for ; Fri, 20 Mar 2020 08:56:47 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727002AbgCTI4l (ORCPT ); Fri, 20 Mar 2020 04:56:41 -0400 Received: from mx2.suse.de ([195.135.220.15]:43272 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726232AbgCTI4k (ORCPT ); Fri, 20 Mar 2020 04:56:40 -0400 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.220.254]) by mx2.suse.de (Postfix) with ESMTP id E7528AB76; Fri, 20 Mar 2020 08:56:38 +0000 (UTC) From: Davidlohr Bueso To: tglx@linutronix.de Cc: arnd@arndb.de, balbi@kernel.org, bhelgaas@google.com, bigeasy@linutronix.de, dave@stgolabs.net, davem@davemloft.net, gregkh@linuxfoundation.org, joel@joelfernandes.org, kurt.schwemmer@microsemi.com, kvalo@codeaurora.org, linux-kernel@vger.kernel.org, linux-pci@vger.kernel.org, linux-usb@vger.kernel.org, linux-wireless@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, logang@deltatee.com, mingo@kernel.org, mpe@ellerman.id.au, netdev@vger.kernel.org, oleg@redhat.com, paulmck@kernel.org, peterz@infradead.org, rdunlap@infradead.org, rostedt@goodmis.org, torvalds@linux-foundation.org, will@kernel.org, Davidlohr Bueso Subject: [PATCH 17/15] rcuwait: Inform rcuwait_wake_up() users if a wakeup was attempted Date: Fri, 20 Mar 2020 01:55:25 -0700 Message-Id: <20200320085527.23861-2-dave@stgolabs.net> X-Mailer: git-send-email 2.16.4 In-Reply-To: <20200320085527.23861-1-dave@stgolabs.net> References: <20200318204302.693307984@linutronix.de> <20200320085527.23861-1-dave@stgolabs.net> Sender: linux-usb-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-usb@vger.kernel.org Let the caller know if wake_up_process() was actually called or not; some users can use this information for ad-hoc. Of course returning true does not guarantee that wake_up_process() actually woke anything up. Signed-off-by: Davidlohr Bueso --- include/linux/rcuwait.h | 2 +- kernel/exit.c | 10 ++++++++-- 2 files changed, 9 insertions(+), 3 deletions(-) diff --git a/include/linux/rcuwait.h b/include/linux/rcuwait.h index 6e8798458091..3f83b9a12ad3 100644 --- a/include/linux/rcuwait.h +++ b/include/linux/rcuwait.h @@ -24,7 +24,7 @@ static inline void rcuwait_init(struct rcuwait *w) w->task = NULL; } -extern void rcuwait_wake_up(struct rcuwait *w); +extern bool rcuwait_wake_up(struct rcuwait *w); /* * The caller is responsible for locking around rcuwait_wait_event(), diff --git a/kernel/exit.c b/kernel/exit.c index 6cc6cc485d07..b0bb0a8ec4b1 100644 --- a/kernel/exit.c +++ b/kernel/exit.c @@ -234,9 +234,10 @@ void release_task(struct task_struct *p) goto repeat; } -void rcuwait_wake_up(struct rcuwait *w) +bool rcuwait_wake_up(struct rcuwait *w) { struct task_struct *task; + bool ret = false; rcu_read_lock(); @@ -254,10 +255,15 @@ void rcuwait_wake_up(struct rcuwait *w) smp_mb(); /* (B) */ task = rcu_dereference(w->task); - if (task) + if (task) { wake_up_process(task); + ret = true; + } rcu_read_unlock(); + + return ret; } +EXPORT_SYMBOL_GPL(rcuwait_wake_up); /* * Determine if a process group is "orphaned", according to the POSIX