From mboxrd@z Thu Jan 1 00:00:00 1970 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 C321DC77B75 for ; Tue, 9 May 2023 18:03:46 +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:MIME-Version:Message-ID:Date:References :In-Reply-To:Subject:Cc:To:From:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=GXXjMSRkZEx6nzpGdUdJCYPI4I5f2tv0ttYCg/T71GM=; b=IjNFVGd5XtYDEs xQnyfnRXtMzREj6Bz7a6uTtQ+J7IwkGAYhmQ3DllXgnhSEPLJd99UdIJVq6sX6aP/gm42q/r+KnVK 489TLkaEyytbR4NWxlDM3z7fZjNJq89gbY8BCnDvgEygonO/f4VT7yJEcLBGYngWJSABJwyFd2IXB bJ0o1+5degylfVUBKJ7SfP/LlC9b86nawUh2OjXkpOCOybkt5pk+tiVl6lJAhM+Pz/67wmlPO091T 52juOet+3DlUPkC3beU06Nl/BO601IqR66UVe/1u8suNsLedxt1dc0PXkYJ+S9cFV625nLh8v3RLT vlCGbVo1sCmaQgk9abbg==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.96 #2 (Red Hat Linux)) id 1pwRgY-003xcF-0P; Tue, 09 May 2023 18:03:38 +0000 Received: from galois.linutronix.de ([193.142.43.55]) by bombadil.infradead.org with esmtps (Exim 4.96 #2 (Red Hat Linux)) id 1pwRgU-003xbS-2l; Tue, 09 May 2023 18:03:36 +0000 From: Thomas Gleixner DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1683655413; 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: in-reply-to:in-reply-to:references:references; bh=H8lMKg/Pl8bB6qnYC08+nBqTm61HWmUyuaLIaj1gFuQ=; b=p/DT4GAI2EtIvZG/E48g6Y7O0PSW6I7fXi+Elpt8is0SHczyNHYG4WQo1p8SYYocLErxKG tmvgrxjIF+UxfScN840YPnkbKctQmYUakhWVsbINnsqgaMlRICOjt3Qfc6Up2X1bjDtoAO ar+k+iD6nwCsxY3BjhAFgFJUIEJHTt1PrRE8rbODQZgYjBKNgq6ykZLI1Uu1z7pabrzvU3 BwVO+gXxHyh4uHTSjhXVxYRN+IF1E8Jy0qeflsgMafTVMfAIUm1oLIOiNDcRtX6ADo3QXJ K1YoDfr+wSZLKitYMptlFZ4BJxPZWh1AEKhWq/8P8VH08qDCjiggV3Xig5/J1w== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1683655413; 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: in-reply-to:in-reply-to:references:references; bh=H8lMKg/Pl8bB6qnYC08+nBqTm61HWmUyuaLIaj1gFuQ=; b=o/GeRRk5OesDmJnkkrzpp/P4MfatYoS6Fv9RucWpaz9lKWhE91kzNOmkETuNZ878NLl+Jz nDab+Y4hdtD/OPAA== To: Peter Zijlstra Cc: LKML , 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)" , David Woodhouse Subject: Re: [patch v3 08/36] x86/smpboot: Split up native_cpu_up() into separate phases and document them In-Reply-To: <20230509101902.GV83892@hirez.programming.kicks-ass.net> References: <20230508181633.089804905@linutronix.de> <20230508185217.671595388@linutronix.de> <20230509101902.GV83892@hirez.programming.kicks-ass.net> Date: Tue, 09 May 2023 20:03:32 +0200 Message-ID: <87lehxz8jv.ffs@tglx> MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20230509_110335_060428_CB4AE4F3 X-CRM114-Status: GOOD ( 16.81 ) 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: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-riscv" Errors-To: linux-riscv-bounces+linux-riscv=archiver.kernel.org@lists.infradead.org On Tue, May 09 2023 at 12:19, Peter Zijlstra wrote: > Again, not really this patch, but since I had to look at this code .... > > On Mon, May 08, 2023 at 09:43:39PM +0200, Thomas Gleixner wrote: >> @@ -1048,60 +1066,89 @@ static int do_boot_cpu(int apicid, int c > > /* > * AP might wait on cpu_callout_mask in cpu_init() with > * cpu_initialized_mask set if previous attempt to online > * it timed-out. Clear cpu_initialized_mask so that after > * INIT/SIPI it could start with a clean state. > */ > cpumask_clear_cpu(cpu, cpu_initialized_mask); > smp_mb(); > > ^^^ that barrier is weird too, cpumask_clear_cpu() is an atomic op and > implies much the same (this is x86 after all). If you want to be super > explicit about it write: > > smp_mb__after_atomic(); > > (which is a no-op) but then it still very much requires a comment as to > what exactly it orders against what. Won't bother either as that mask is gone a few patches later. _______________________________________________ linux-riscv mailing list linux-riscv@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-riscv