From nobody Sun Feb 8 12:20:35 2026 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 EBD02C77B75 for ; Tue, 16 May 2023 09:11:38 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231985AbjEPJLf (ORCPT ); Tue, 16 May 2023 05:11:35 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:46156 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231823AbjEPJKH (ORCPT ); Tue, 16 May 2023 05:10:07 -0400 Received: from galois.linutronix.de (Galois.linutronix.de [193.142.43.55]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id C97F2359D; Tue, 16 May 2023 02:10:04 -0700 (PDT) Date: Tue, 16 May 2023 09:09:59 -0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1684228199; h=from:from:sender:sender:reply-to:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=BVk9My4DLgcAs6qBcIJAUiGEG+aQrBL9FHQdkLIbdsA=; b=i90SHFhhIwzNyEHj1aw3/TK74v8N9L2mD/skmZIPzB9k2B0dc2Of3/uAt4OKSNB5ltwbjc zPTPfz5qoyYWakNBz2vh3cZLrIQXoijMWofXZTt1cp9Ra6qxrS9YpE0Zb2hUtroqQ5cOHt btQMjxXgcvXstEpCH6YnEQWr9aMQRAfbTe+mlng9uxaJg4lc+ZSAQ91JiI+2aMh3j5e8VY oxhUEXXV7Ej6xnbCScgBrPBW556BaJCyNaHlQrcSU6HlAcQ78Y07WrkaKRcLveCoBU679/ 5IbnPXnANLHOv6fMPbgYyHfUjwvDm6AmtTiu3rUoAw9asqr5v7+tfYjTDnJxOA== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1684228199; h=from:from:sender:sender:reply-to:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=BVk9My4DLgcAs6qBcIJAUiGEG+aQrBL9FHQdkLIbdsA=; b=VgJCr3gZXfhFPYCrnQOmY62+awqoNNYXOJS7egAo0tQsLM6Z50/lmnROj2wVnKWpzJs42/ b6b++bB5aEON0TDw== From: "tip-bot2 for Thomas Gleixner" Sender: tip-bot2@linutronix.de Reply-to: linux-kernel@vger.kernel.org To: linux-tip-commits@vger.kernel.org Subject: [tip: smp/core] x86/smpboot: Remove wait for cpu_online() Cc: Thomas Gleixner , "Peter Zijlstra (Intel)" , Michael Kelley , Oleksandr Natalenko , Helge Deller , "Guilherme G. Piccoli" , x86@kernel.org, linux-kernel@vger.kernel.org In-Reply-To: <20230512205256.316417181@linutronix.de> References: <20230512205256.316417181@linutronix.de> MIME-Version: 1.0 Message-ID: <168422819946.404.17515488991384731626.tip-bot2@tip-bot2> Robot-ID: Robot-Unsubscribe: Contact to get blacklisted from these emails Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The following commit has been merged into the smp/core branch of tip: Commit-ID: e464640cf7af12f3c2748065936b95eae1f735ba Gitweb: https://git.kernel.org/tip/e464640cf7af12f3c2748065936b95eae= 1f735ba Author: Thomas Gleixner AuthorDate: Fri, 12 May 2023 23:07:22 +02:00 Committer: Peter Zijlstra CommitterDate: Mon, 15 May 2023 13:44:54 +02:00 x86/smpboot: Remove wait for cpu_online() Now that the core code drops sparse_irq_lock after the idle thread synchronized, it's pointless to wait for the AP to mark itself online. Signed-off-by: Thomas Gleixner Signed-off-by: Peter Zijlstra (Intel) Tested-by: Michael Kelley Tested-by: Oleksandr Natalenko Tested-by: Helge Deller # parisc Tested-by: Guilherme G. Piccoli # Steam Deck Link: https://lore.kernel.org/r/20230512205256.316417181@linutronix.de --- arch/x86/kernel/smpboot.c | 26 ++------------------------ 1 file changed, 2 insertions(+), 24 deletions(-) diff --git a/arch/x86/kernel/smpboot.c b/arch/x86/kernel/smpboot.c index 3f731be..4349e8a 100644 --- a/arch/x86/kernel/smpboot.c +++ b/arch/x86/kernel/smpboot.c @@ -275,7 +275,6 @@ static void notrace start_secondary(void *unused) * half valid vector space. */ lock_vector_lock(); - /* Sync point with do_wait_cpu_online() */ set_cpu_online(smp_processor_id(), true); lapic_online(); unlock_vector_lock(); @@ -1104,20 +1103,6 @@ static int wait_cpu_initialized(unsigned int cpu) return 0; } =20 -/* - * Bringup step three: Wait for the target AP to reach set_cpu_online() in - * start_secondary(). - */ -static void wait_cpu_online(unsigned int cpu) -{ - /* - * Wait for the AP to mark itself online, so the core caller - * can drop sparse_irq_lock. - */ - while (!cpu_online(cpu)) - schedule(); -} - static int native_kick_ap(unsigned int cpu, struct task_struct *tidle) { int apicid =3D apic->cpu_present_to_apicid(cpu); @@ -1164,16 +1149,9 @@ int native_cpu_up(unsigned int cpu, struct task_stru= ct *tidle) int ret; =20 ret =3D native_kick_ap(cpu, tidle); - if (ret) - goto out; - - ret =3D wait_cpu_initialized(cpu); - if (ret) - goto out; - - wait_cpu_online(cpu); + if (!ret) + ret =3D wait_cpu_initialized(cpu); =20 -out: /* Cleanup possible dangling ends... */ if (x86_platform.legacy.warm_reset) smpboot_restore_warm_reset_vector();