From patchwork Wed Nov 23 20:18:42 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Thomas Gleixner X-Patchwork-Id: 628449 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 6609BC433FE for ; Wed, 23 Nov 2022 20:20:57 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S239720AbiKWUU4 (ORCPT ); Wed, 23 Nov 2022 15:20:56 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41750 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S237373AbiKWUUP (ORCPT ); Wed, 23 Nov 2022 15:20:15 -0500 Received: from galois.linutronix.de (Galois.linutronix.de [193.142.43.55]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id B8D10B043A; Wed, 23 Nov 2022 12:18:44 -0800 (PST) Message-ID: <20221123201624.888306160@linutronix.de> DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1669234723; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: references:references; bh=0eY7YnzlwSNTQTRTn0uxqikX7ma7laOZXEtpEJOrwxM=; b=4opf8+/GOXjJNOy6hPzmeTt80WMzIFSy8Am96kclq97AQbJnWOAprC4vzZ1RZ9AbWkSeZk 8zxZ4sxeVeoBFgxABFY7ezWo75DXTTNGhM4D5jOMM2E+O2bn+NeGpqfZXBMXe7fEmBdJvK wTJmhUcJZEEsksW+Dkwxwh463sn4aIwrjxMUuHxBlkF9QQB2GcTpqhScr8KqDSwvF2OQfy 8ahBVUYnd/xMAqaBzHyud1lYvkZsmsdMMFwp5r3zMlwNBcALp9chFIOkhiH4aIdZi99Xj4 l/Rge2vagqPxQK11ZT3jUQu2tE7GP+DsyoC3XzfC0xe7A+phaeCOUeMdBjcw9w== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1669234723; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: references:references; bh=0eY7YnzlwSNTQTRTn0uxqikX7ma7laOZXEtpEJOrwxM=; b=qUhbnPp1lnq6hw/ZiuMuZPtuw5rIwxw31eQbsu7Um9qICRI4gv+9DhpXmFjAUdmwFAtvnr 9j34rhZTb7lka7Cg== From: Thomas Gleixner To: LKML Cc: Linus Torvalds , Steven Rostedt , Anna-Maria Behnsen , Peter Zijlstra , Stephen Boyd , Guenter Roeck , Andrew Morton , Julia Lawall , Arnd Bergmann , Viresh Kumar , Marc Zyngier , Marcel Holtmann , Johan Hedberg , Luiz Augusto von Dentz , linux-bluetooth@vger.kernel.org, "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , netdev@vger.kernel.org, Jacob Keller Subject: [patch V3 08/17] timers: Use del_timer_sync() even on UP References: <20221123201306.823305113@linutronix.de> MIME-Version: 1.0 Date: Wed, 23 Nov 2022 21:18:42 +0100 (CET) Precedence: bulk List-ID: X-Mailing-List: linux-bluetooth@vger.kernel.org del_timer_sync() is assumed to be pointless on uniprocessor systems and can be mapped to del_timer() because in theory del_timer() can never be invoked while the timer callback function is executed. This is not entirely true because del_timer() can be invoked from interrupt context and therefore hit in the middle of a running timer callback. Contrary to that del_timer_sync() is not allowed to be invoked from interrupt context unless the affected timer is marked with TIMER_IRQSAFE. del_timer_sync() has proper checks in place to detect such a situation. Give up on the UP optimization and make del_timer_sync() unconditionally available. Co-developed-by: Steven Rostedt Signed-off-by: Steven Rostedt Signed-off-by: Thomas Gleixner Tested-by: Guenter Roeck Reviewed-by: Jacob Keller Link: https://lore.kernel.org/all/20220407161745.7d6754b3@gandalf.local.home Link: https://lore.kernel.org/all/20221110064101.429013735@goodmis.org --- include/linux/timer.h | 7 +------ kernel/time/timer.c | 2 -- 2 files changed, 1 insertion(+), 8 deletions(-) --- a/include/linux/timer.h +++ b/include/linux/timer.h @@ -183,12 +183,7 @@ extern int timer_reduce(struct timer_lis extern void add_timer(struct timer_list *timer); extern int try_to_del_timer_sync(struct timer_list *timer); - -#if defined(CONFIG_SMP) || defined(CONFIG_PREEMPT_RT) - extern int del_timer_sync(struct timer_list *timer); -#else -# define del_timer_sync(t) del_timer(t) -#endif +extern int del_timer_sync(struct timer_list *timer); extern void init_timers(void); struct hrtimer; --- a/kernel/time/timer.c +++ b/kernel/time/timer.c @@ -1396,7 +1396,6 @@ static inline void timer_sync_wait_runni static inline void del_timer_wait_running(struct timer_list *timer) { } #endif -#if defined(CONFIG_SMP) || defined(CONFIG_PREEMPT_RT) /** * del_timer_sync - Deactivate a timer and wait for the handler to finish. * @timer: The timer to be deactivated @@ -1477,7 +1476,6 @@ int del_timer_sync(struct timer_list *ti return ret; } EXPORT_SYMBOL(del_timer_sync); -#endif static void call_timer_fn(struct timer_list *timer, void (*fn)(struct timer_list *),