From mboxrd@z Thu Jan 1 00:00:00 1970 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 D995BC4332F for ; Tue, 22 Nov 2022 17:45:51 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234542AbiKVRpu (ORCPT ); Tue, 22 Nov 2022 12:45:50 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:59566 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234366AbiKVRp2 (ORCPT ); Tue, 22 Nov 2022 12:45:28 -0500 Received: from galois.linutronix.de (Galois.linutronix.de [193.142.43.55]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 6A9E8D9F; Tue, 22 Nov 2022 09:44:59 -0800 (PST) Message-ID: <20221122173648.560770928@linutronix.de> DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1669139097; 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=EMpM2Y9+AZ3Mkc+gVMKWk6eghahsVVjAJyXVQ6CR7oc=; b=jOfQSKgiI43Mey5tMtwdwq5HcuqumunlijHH9jFhIuNmnqNMa09hn7oPyucrb3Fb7Hy247 sBgZzHiczM2XHBKwQ/4ZYgkb4s+rZsXYUF3Hlb5PGQpHYZMAcnEqweoxl780oo2E/ncE12 TMxE0d0PhCN97Le4qcdR6JQdxsiQn14ANd53XDmF449szrYZKxUH2Pb664Sf0h4nlVhh0T iVDuKH07E3dFD9TiKVSrbxfy62RC2mLgBJFWStGvY+tVP7RsoeKUtLxXtgQdSFS8Eax6aP QOpN12SrPjoFzA6VWLkFtiCkDix5G133PH+yLVfd6KG+DRNqCUrt/OQ4vhBXxA== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1669139097; 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=EMpM2Y9+AZ3Mkc+gVMKWk6eghahsVVjAJyXVQ6CR7oc=; b=BWp8Zh//+2G8dMEG6BXVGDbM34z0AVD4jWkQgirweP06NXhIGCtYfEjeg8i9J72JprjMmF MOrJTm31/GbXkIBg== 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 Subject: [patch V2 08/17] timers: Use del_timer_sync() even on UP References: <20221122171312.191765396@linutronix.de> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Date: Tue, 22 Nov 2022 18:44:57 +0100 (CET) Precedence: bulk List-ID: X-Mailing-List: linux-kernel@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 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 @@ -1392,7 +1392,6 @@ 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 @@ -1473,7 +1472,6 @@ 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 *),