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: 13234867 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 lists.xenproject.org (lists.xenproject.org [192.237.175.120]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 0318BC77B7F for ; Mon, 8 May 2023 19:44:05 +0000 (UTC) Received: from list by lists.xenproject.org with outflank-mailman.531759.827638 (Exim 4.92) (envelope-from ) id 1pw6m1-0000OM-IN; Mon, 08 May 2023 19:43:53 +0000 X-Outflank-Mailman: Message body and most headers restored to incoming version Received: by outflank-mailman (output) from mailman id 531759.827638; Mon, 08 May 2023 19:43:53 +0000 Received: from localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1pw6m1-0000K1-0u; Mon, 08 May 2023 19:43:53 +0000 Received: by outflank-mailman (input) for mailman id 531759; Mon, 08 May 2023 19:43:51 +0000 Received: from se1-gles-flk1-in.inumbo.com ([94.247.172.50] helo=se1-gles-flk1.inumbo.com) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1pw6lz-0004Y5-H2 for xen-devel@lists.xenproject.org; Mon, 08 May 2023 19:43:51 +0000 Received: from galois.linutronix.de (galois.linutronix.de [193.142.43.55]) by se1-gles-flk1.inumbo.com (Halon) with ESMTPS id a79d0dee-edd8-11ed-8611-37d641c3527e; Mon, 08 May 2023 21:43:50 +0200 (CEST) X-BeenThere: xen-devel@lists.xenproject.org List-Id: Xen developer discussion List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Errors-To: xen-devel-bounces@lists.xenproject.org Precedence: list Sender: "Xen-devel" X-Inumbo-ID: a79d0dee-edd8-11ed-8611-37d641c3527e 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) 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)