From patchwork Thu May 4 19:02:21 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Thomas Gleixner X-Patchwork-Id: 13231515 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 9D8BAC7EE25 for ; Thu, 4 May 2023 19:03:35 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229462AbjEDTDe (ORCPT ); Thu, 4 May 2023 15:03:34 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:50880 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230139AbjEDTCw (ORCPT ); Thu, 4 May 2023 15:02:52 -0400 Received: from galois.linutronix.de (Galois.linutronix.de [193.142.43.55]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 49AD37A98; Thu, 4 May 2023 12:02:23 -0700 (PDT) Message-ID: <20230504185937.088861348@linutronix.de> DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1683226941; 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=waR3DpyQ6DyvK8jEESlEb5rxqBYC2I7FeZ3H8ZtIrVQ=; b=HKYLcl9cklgr6YO5/NspFjC+D2CCt/ZYWzxxiOOGuCX7u/7IGOq81DQhVq9PvbBHY6Kpcr SxWHo0Ub70GUTAFkoXjKOB1ZyWdtlCAv2pBsav0oFkFgcMqJgiDoblcu2Hnt6D2hLbDJE7 kec7wtFBfE1xoWI2cME3sJv8K73WrIvhYqzB8k1hCePY7f28tWiYPkzCL3lKJ1aAZjMvt+ kXyU82XPa0OHMGsQ8hlC+TxCd6BOdr1gglOHT1fZhwBJGZCjFBU2Yxs7+XALa+aaWrMaCV mvw2zjNCImLQQhSEXScVL50CeJT6NF1GH6WIuPs8AGymg+ULRPU3wowu71D4Lw== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1683226941; 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=waR3DpyQ6DyvK8jEESlEb5rxqBYC2I7FeZ3H8ZtIrVQ=; b=XDnjEy7a3qUl/tWMxBUIj3PidEk2DRdxC5hulFnew5UcHpu5yRDRS/g5aolbe6p1RMLJCX rQwCSliTpoNYDfAw== 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 V2 14/38] cpu/hotplug: Rework sparse_irq locking in bringup_cpu() References: <20230504185733.126511787@linutronix.de> MIME-Version: 1.0 Date: Thu, 4 May 2023 21:02:21 +0200 (CEST) Precedence: bulk List-ID: X-Mailing-List: linux-mips@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 --- 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)