From patchwork Fri May 12 21:07:22 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Thomas Gleixner X-Patchwork-Id: 13239768 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 33593C7EE2D for ; Fri, 12 May 2023 21:08:45 +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=I6v84iqvIvs6iCvAxvCi9m19QqeSw4VRFMKGg2WM6bA=; b=NEzw9blO2g3u6Z f3136oOLaizcwlj0h5ELh9AeHwwgAyE3EKaDmAUmNKpc1lNi+czYf1h+xim8eRwimEpt6RKAkcKkG LMjmjjfInpzsrjlHEhJclXz+Z78tr4Y44Rth6lfRm42YNr7NbBseGv82UfkY1rAyMYNGtM/fsuS3a avlan7OQBC32gX7dTNZLWe54ekw+uoiPP/q2drrRr6Mv7wQxNqqXh++sY7BYYFvKl7CzVuXnowSvg mXGMjZ5rPpdgSHjlTz/G5/w9IrdNmOQt1FQk6nevjyh1/AzlLC+YWFi/O3Fz3K2jNPFII5elWFt6T P/m8vSca0vsIljhrCcXg==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.96 #2 (Red Hat Linux)) id 1pxa0F-00CzqL-15; Fri, 12 May 2023 21:08:39 +0000 Received: from galois.linutronix.de ([193.142.43.55]) by bombadil.infradead.org with esmtps (Exim 4.96 #2 (Red Hat Linux)) id 1pxZz2-00CydD-1Q; Fri, 12 May 2023 21:07:26 +0000 Message-ID: <20230512205256.316417181@linutronix.de> DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1683925643; 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=DlXLIimSUyDsLnpaLCie3XUbsPcjE+B3Y5/np73/syk=; b=0n8XyUqdMKHvhCV5NvBs8uq0bkyvVXbfLtaGYG0ApQJEOyilZiFp81ncYSBr6upR2FGS65 C/nM69M5fEGpiISmkmAowedNeMh8stJLEoOo7kEL2Yn2+06PaBevfLVashkK38xEMls2k0 f/2djYvKqyUSewvgr/tLWZAR3cGWoQ2BFlZWa6eUYCxL/R/BBbwHpxF3oihmcCNqrcO5vL DdSUgTidw3Y3j0rys0Ztwy/cnS3zHqjKWZhecFMnqr4ICUwW5Yz4Fvu/UCxs3vooavSjLb kpbMhzb9bUAKVmUd7V7KcFTAjo4mQTSyfyHcI0YMf+BOz6gUP+32KRGIcgecpA== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1683925643; 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=DlXLIimSUyDsLnpaLCie3XUbsPcjE+B3Y5/np73/syk=; b=NxwadJuaL5bNYJvtkxpDH+oWBvMqBd0ae6N3DUYGY2xW3p33/XvIRC9MwzW0Aq6/9Tjy03 UcA8T+Ga+8Z9ZeBg== 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)" , Ross Philipson Subject: [patch V4 16/37] x86/smpboot: Remove wait for cpu_online() References: <20230512203426.452963764@linutronix.de> MIME-Version: 1.0 Date: Fri, 12 May 2023 23:07:22 +0200 (CEST) X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20230512_140724_650325_089D1A24 X-CRM114-Status: GOOD ( 12.33 ) X-BeenThere: linux-riscv@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-riscv" Errors-To: linux-riscv-bounces+linux-riscv=archiver.kernel.org@lists.infradead.org From: Thomas Gleixner 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 Tested-by: Michael Kelley --- arch/x86/kernel/smpboot.c | 26 ++------------------------ 1 file changed, 2 insertions(+), 24 deletions(-) --- a/arch/x86/kernel/smpboot.c +++ b/arch/x86/kernel/smpboot.c @@ -275,7 +275,6 @@ static void notrace start_secondary(void * 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 return 0; } -/* - * 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 = apic->cpu_present_to_apicid(cpu); @@ -1164,16 +1149,9 @@ int native_cpu_up(unsigned int cpu, stru int ret; ret = native_kick_ap(cpu, tidle); - if (ret) - goto out; - - ret = wait_cpu_initialized(cpu); - if (ret) - goto out; - - wait_cpu_online(cpu); + if (!ret) + ret = wait_cpu_initialized(cpu); -out: /* Cleanup possible dangling ends... */ if (x86_platform.legacy.warm_reset) smpboot_restore_warm_reset_vector();