From nobody Wed Dec 17 12:54:44 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 CFF88C07545 for ; Wed, 25 Oct 2023 18:04:49 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234496AbjJYSEt (ORCPT ); Wed, 25 Oct 2023 14:04:49 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:49486 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230035AbjJYSEr (ORCPT ); Wed, 25 Oct 2023 14:04:47 -0400 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id F14F2123 for ; Wed, 25 Oct 2023 11:04:43 -0700 (PDT) Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 5202A1FB; Wed, 25 Oct 2023 11:05:25 -0700 (PDT) Received: from merodach.members.linode.com (unknown [172.31.20.19]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 6DFB83F738; Wed, 25 Oct 2023 11:04:40 -0700 (PDT) From: James Morse To: x86@kernel.org, linux-kernel@vger.kernel.org Cc: Fenghua Yu , Reinette Chatre , Thomas Gleixner , Ingo Molnar , Borislav Petkov , H Peter Anvin , Babu Moger , James Morse , shameerali.kolothum.thodi@huawei.com, D Scott Phillips OS , carl@os.amperecomputing.com, lcherian@marvell.com, bobo.shaobowang@huawei.com, tan.shaopeng@fujitsu.com, baolin.wang@linux.alibaba.com, Jamie Iles , Xin Hao , peternewman@google.com, dfustini@baylibre.com, amitsinght@marvell.com, Frederic Weisbecker Subject: [PATCH v7 01/24] tick/nohz: Move tick_nohz_full_mask declaration outside the #ifdef Date: Wed, 25 Oct 2023 18:03:22 +0000 Message-Id: <20231025180345.28061-2-james.morse@arm.com> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20231025180345.28061-1-james.morse@arm.com> References: <20231025180345.28061-1-james.morse@arm.com> 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" tick_nohz_full_mask lists the CPUs that are nohz_full. This is only needed when CONFIG_NO_HZ_FULL is defined. tick_nohz_full_cpu() allows a specific CPU to be tested against the mask, and evaluates to false when CONFIG_NO_HZ_FULL is not defined. The resctrl code needs to pick a CPU to run some work on, a new helper prefers housekeeping CPUs by examining the tick_nohz_full_mask. Hiding the declaration behind #ifdef CONFIG_NO_HZ_FULL forces all the users to be behind an ifdef too. Move the tick_nohz_full_mask declaration, this lets callers drop the ifdef, and guard access to tick_nohz_full_mask with IS_ENABLED() or something like tick_nohz_full_cpu(). The definition does not need to be moved as any callers should be removed at compile time unless CONFIG_NO_HZ_FULL is defined. Tested-by: Shaopeng Tan Tested-by: Peter Newman Reviewed-by: Shaopeng Tan Acked-by: Reinette Chatre # for resctrl depende= ncy CC: Frederic Weisbecker Signed-off-by: James Morse --- No changes since v6 include/linux/tick.h | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-) diff --git a/include/linux/tick.h b/include/linux/tick.h index 716d17f31c45..0fb903838dfb 100644 --- a/include/linux/tick.h +++ b/include/linux/tick.h @@ -164,9 +164,16 @@ static inline u64 get_cpu_idle_time_us(int cpu, u64 *u= nused) { return -1; } static inline u64 get_cpu_iowait_time_us(int cpu, u64 *unused) { return -1= ; } #endif /* !CONFIG_NO_HZ_COMMON */ =20 +/* + * Mask of CPUs that are nohz_full. + * + * Users should be guarded by CONFIG_NO_HZ_FULL or a tick_nohz_full_cpu() + * check. + */ +extern cpumask_var_t tick_nohz_full_mask; + #ifdef CONFIG_NO_HZ_FULL extern bool tick_nohz_full_running; -extern cpumask_var_t tick_nohz_full_mask; =20 static inline bool tick_nohz_full_enabled(void) { --=20 2.39.2