From nobody Wed Sep 10 02:01:38 2025 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 E5576E7B605 for ; Wed, 4 Oct 2023 12:36:31 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S242641AbjJDMgb (ORCPT ); Wed, 4 Oct 2023 08:36:31 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:39458 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S242393AbjJDMfn (ORCPT ); Wed, 4 Oct 2023 08:35:43 -0400 Received: from galois.linutronix.de (Galois.linutronix.de [193.142.43.55]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 91FB6D9 for ; Wed, 4 Oct 2023 05:35:33 -0700 (PDT) From: Anna-Maria Behnsen DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1696422932; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=R6p91zzmcTgFtBegVAgz86f9rPOZl2ESGLLtaCGNKmE=; b=tD5J+oiaWrqrU1ELhMzwRcDVY01AqSqRWzluw0BE0LA9bqRLkpt/mTPfu/6X5qYIQm7/6r azGNPmxrTGX7M2KTsSaEQRGMORPVKnsrDvvFjl+6VtmnFZkZxfhv0EHg11C43a9GDqIK8v hObFc6IZs5xltBwsQNQqQdhb+2tQyhVnb2M8nZ9EOzfOPwZT9WKv38d4wGpGPnyYvdfBa4 haJBSp9CEa4z2BOe6Gn/QavcG2GTsHfKTbAklvgqN2PhubiqwOBTL4eEuIe42UwiNbHReY QIK0UzjalspQk7MYaH2vRt2OIs8Hy+joCll0qaReQlsAc9J9mxb6NkTJmI3QmA== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1696422932; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=R6p91zzmcTgFtBegVAgz86f9rPOZl2ESGLLtaCGNKmE=; b=p4HI0TmibWqsmsZsVt86GITKCM8Cm5JkQzQKKPtx1yqL/g4yCL49TSeheoAImYhl51+X6o DFLUUenUA6uxCwAw== To: linux-kernel@vger.kernel.org Cc: Peter Zijlstra , John Stultz , Thomas Gleixner , Eric Dumazet , "Rafael J . Wysocki" , Arjan van de Ven , "Paul E . McKenney" , Frederic Weisbecker , Rik van Riel , Steven Rostedt , Sebastian Siewior , Giovanni Gherdovich , Lukasz Luba , "Gautham R . Shenoy" , Srinivas Pandruvada , K Prateek Nayak , Anna-Maria Behnsen Subject: [PATCH v8 11/25] timers: Introduce add_timer() variants which modify timer flags Date: Wed, 4 Oct 2023 14:34:40 +0200 Message-Id: <20231004123454.15691-12-anna-maria@linutronix.de> In-Reply-To: <20231004123454.15691-1-anna-maria@linutronix.de> References: <20231004123454.15691-1-anna-maria@linutronix.de> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" Timer might be used as pinned timer (using add_timer_on()) and later on as non pinned timers using add_timer(). When the NOHZ timer pull at expiry model is in place, TIMER_PINNED flag is required to be used whenever a timer needs to expire on a dedicated CPU. Flag must no be set, if expiration on a dedicated CPU is not required. add_timer_on()'s behavior will be changed during the preparation patches for the NOHZ timer pull at expiry model to unconditionally set TIMER_PINNED flag. To be able to reset/set the flag when queueing a timer, two variants of add_timer() are introduced. This is a preparatory patch and has no functional change. Signed-off-by: Anna-Maria Behnsen --- New in v6 --- include/linux/timer.h | 2 ++ kernel/time/timer.c | 34 ++++++++++++++++++++++++++++++++++ 2 files changed, 36 insertions(+) diff --git a/include/linux/timer.h b/include/linux/timer.h index 9162f275819a..6f96661480dd 100644 --- a/include/linux/timer.h +++ b/include/linux/timer.h @@ -180,6 +180,8 @@ extern int timer_reduce(struct timer_list *timer, unsig= ned long expires); #define NEXT_TIMER_MAX_DELTA ((1UL << 30) - 1) =20 extern void add_timer(struct timer_list *timer); +extern void add_timer_local(struct timer_list *timer); +extern void add_timer_global(struct timer_list *timer); =20 extern int try_to_del_timer_sync(struct timer_list *timer); extern int timer_delete_sync(struct timer_list *timer); diff --git a/kernel/time/timer.c b/kernel/time/timer.c index 8518f7aa7319..3172b8094097 100644 --- a/kernel/time/timer.c +++ b/kernel/time/timer.c @@ -1245,6 +1245,40 @@ void add_timer(struct timer_list *timer) } EXPORT_SYMBOL(add_timer); =20 +/** + * add_timer_local - Start a timer on the local CPU + * @timer: The timer to be started + * + * Same as add_timer() except that the timer flag TIMER_PINNED is set. + * + * See add_timer() for further details. + */ +void add_timer_local(struct timer_list *timer) +{ + if (WARN_ON_ONCE(timer_pending(timer))) + return; + timer->flags |=3D TIMER_PINNED; + __mod_timer(timer, timer->expires, MOD_TIMER_NOTPENDING); +} +EXPORT_SYMBOL(add_timer_local); + +/** + * add_timer_global - Start a timer without TIMER_PINNED flag set + * @timer: The timer to be started + * + * Same as add_timer() except that the timer flag TIMER_PINNED is unset. + * + * See add_timer() for further details. + */ +void add_timer_global(struct timer_list *timer) +{ + if (WARN_ON_ONCE(timer_pending(timer))) + return; + timer->flags &=3D ~TIMER_PINNED; + __mod_timer(timer, timer->expires, MOD_TIMER_NOTPENDING); +} +EXPORT_SYMBOL(add_timer_global); + /** * add_timer_on - Start a timer on a particular CPU * @timer: The timer to be started --=20 2.39.2