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: 13231590 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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (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 205A4C7EE25 for ; Thu, 4 May 2023 19:03:58 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:Date:MIME-Version:References:Subject:Cc :To:From:Message-ID:Reply-To:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:In-Reply-To: List-Owner; bh=LcHZGGxlq/K6V3ygw+VgBMjjTFe79km+f59EOx2VS+w=; b=1mo0+CXmCK0Mhd pKdnGRSPt5Zv10pa+kQDYDTsisI7d7bue3daWQEsBS+lIW8ED6Dch/h//kjOR/762Z2bmqLDqxpWJ Hd23kwLHhWXElvlojLzyK4P9k+Lq7AQK2vGpM9lstqyQTHiUQ5KO3wwn2VxzmVKH3/QDJYD3srtWA OroX6s5GzFn+s4spCqSWE1grWWldksW7FhhGQ6L8/0DVPADv4mMsJyY70BemY0xbGbiLy9zrRcIkq nVDTYoLvlK/wE/cGhx//1YcWhHLAXQRC5vlRViOiWd1SXvVjl1Ou1BpMs7CRi/M7BCAV21ormFIxY 6Qpv6Xgq1Q+ugo2hDfcw==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.96 #2 (Red Hat Linux)) id 1pueEG-008eD9-1d; Thu, 04 May 2023 19:03:00 +0000 Received: from galois.linutronix.de ([193.142.43.55]) by bombadil.infradead.org with esmtps (Exim 4.96 #2 (Red Hat Linux)) id 1pueDe-008dUc-2s; Thu, 04 May 2023 19:02:24 +0000 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) X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20230504_120223_102319_D950FF81 X-CRM114-Status: GOOD ( 12.99 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.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)