From patchwork Mon May 8 19:43:49 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Thomas Gleixner X-Patchwork-Id: 13234883 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 D2992C7EE22 for ; Mon, 8 May 2023 19:44:52 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233864AbjEHTot (ORCPT ); Mon, 8 May 2023 15:44:49 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:58176 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233810AbjEHToT (ORCPT ); Mon, 8 May 2023 15:44:19 -0400 Received: from galois.linutronix.de (Galois.linutronix.de [IPv6:2a0a:51c0:0:12e:550::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id CF6627AA2; Mon, 8 May 2023 12:43:51 -0700 (PDT) Message-ID: <20230508185218.013044883@linutronix.de> DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1683575029; 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=BOT3gWwQF7O/1lZ9KsTIy5NWCf87k83rCpCfGL29bzE=; b=Vtkw853T/g2LgebBW2u5NvRyk/o8vkE9DVNbCjOgfsv8NQAdQ+PiRmVE3YRjVR9zyaPDpW A0CpqtisqwiF90SMSTT3dgMD9wfCYwYlyM9zgdWNPZBK6ove/DWKBEfTIBavRYG3mLpwGW gj5/U4hTXI1gfU5gMpT9O+3nSrnlgwHXON5jO7YTMsIZWUpGn1lUA7aXp/3y1CXCUYBa6o 4saDTE36mpdN94ZK/rdI32a5+qd4XpBBQ9/jSvxCD81AEctXSXlca21oVxip2aNe/i6362 k8ifgTHs2omVUbliI/3cpRSjuph/X6qOreGlkue5SVagGH6iBXC3i5IxD3kMEg== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1683575029; 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=BOT3gWwQF7O/1lZ9KsTIy5NWCf87k83rCpCfGL29bzE=; b=z0rzXlV5+Y57E7wE/hgSxsOIOaBBLImivYo4M54wyRCUx4IHVjFSQS7chfIs3CglORkucG Op/Ji4IG3mTcrvAw== From: Thomas Gleixner To: LKML Cc: x86@kernel.org, David Woodhouse , Andrew Cooper , Brian Gerst , Arjan van de Veen , Paolo Bonzini , Paul McKenney , Tom Lendacky , Sean Christopherson , Oleksandr Natalenko , Paul Menzel , "Guilherme G. Piccoli" , Piotr Gorski , Usama Arif , Juergen Gross , Boris Ostrovsky , xen-devel@lists.xenproject.org, Russell King , Arnd Bergmann , linux-arm-kernel@lists.infradead.org, Catalin Marinas , Will Deacon , Guo Ren , linux-csky@vger.kernel.org, Thomas Bogendoerfer , linux-mips@vger.kernel.org, "James E.J. Bottomley" , Helge Deller , linux-parisc@vger.kernel.org, Paul Walmsley , Palmer Dabbelt , linux-riscv@lists.infradead.org, Mark Rutland , Sabin Rapan , "Michael Kelley (LINUX)" Subject: [patch v3 14/36] [patch V2 14/38] cpu/hotplug: Rework sparse_irq locking in bringup_cpu() References: <20230508181633.089804905@linutronix.de> MIME-Version: 1.0 Date: Mon, 8 May 2023 21:43:49 +0200 (CEST) Precedence: bulk List-ID: X-Mailing-List: linux-parisc@vger.kernel.org From: Thomas Gleixner There is no harm to hold sparse_irq lock until the upcoming CPU completes in cpuhp_online_idle(). This allows to remove cpu_online() synchronization from architecture code. Signed-off-by: Thomas Gleixner Tested-by: Michael Kelley --- kernel/cpu.c | 28 +++++++++++++++++++--------- 1 file changed, 19 insertions(+), 9 deletions(-) --- --- a/kernel/cpu.c +++ b/kernel/cpu.c @@ -558,7 +558,7 @@ static int cpuhp_kick_ap(int cpu, struct return ret; } -static int bringup_wait_for_ap(unsigned int cpu) +static int bringup_wait_for_ap_online(unsigned int cpu) { struct cpuhp_cpu_state *st = per_cpu_ptr(&cpuhp_state, cpu); @@ -579,15 +579,12 @@ static int bringup_wait_for_ap(unsigned */ if (!cpu_smt_allowed(cpu)) return -ECANCELED; - - if (st->target <= CPUHP_AP_ONLINE_IDLE) - return 0; - - return cpuhp_kick_ap(cpu, st, st->target); + return 0; } static int bringup_cpu(unsigned int cpu) { + struct cpuhp_cpu_state *st = per_cpu_ptr(&cpuhp_state, cpu); struct task_struct *idle = idle_thread_get(cpu); int ret; @@ -606,10 +603,23 @@ static int bringup_cpu(unsigned int cpu) /* Arch-specific enabling code. */ ret = __cpu_up(cpu, idle); - irq_unlock_sparse(); if (ret) - return ret; - return bringup_wait_for_ap(cpu); + goto out_unlock; + + ret = bringup_wait_for_ap_online(cpu); + if (ret) + goto out_unlock; + + irq_unlock_sparse(); + + if (st->target <= CPUHP_AP_ONLINE_IDLE) + return 0; + + return cpuhp_kick_ap(cpu, st, st->target); + +out_unlock: + irq_unlock_sparse(); + return ret; } static int finish_cpu(unsigned int cpu)