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 F2126C77B75 for ; Tue, 9 May 2023 12:08:57 +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=OwerNN3c/YXGp4Rgtnh4G6ZtXDkhIJgeGM1A/zWd5xI=; b=WLvNjqJWX7wjLG Ol+PD5WpVOgcQLDwo9kzd/SbdyVAY+3+DRVghwrvkk60Xvcql3XNKRaLc6MAERr3yGZhqoek24Ntt eMsRXkELtBBGLf3vfhKBCHcRk/VR4i0KPNgR/TyTX3pfj/mBtCwDOeYiITMBr7o8ni8VRdYA022DG 2iKdTMf6g8Q6v2qe5YYNX26T0lZa2kDf+EkOhF+hyd1p4cv37FpZuv7waZQPd00aSTlmctPYvcJBz HlIiQ3heLh/zsLpbiWVPo9a5meb5hw2nMEeHdZMvMkP+6FWwdgzLV+ShXqFM9ucxD0kAptH+EFiin slpyVjlzg3UlWoUbi4Fw==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.96 #2 (Red Hat Linux)) id 1pwM99-003EEk-3C; Tue, 09 May 2023 12:08:47 +0000 Received: from desiato.infradead.org ([90.155.92.199]) by bombadil.infradead.org with esmtps (Exim 4.96 #2 (Red Hat Linux)) id 1pwM98-003EDH-1U; Tue, 09 May 2023 12:08:46 +0000 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=desiato.20200630; h=Content-Type:MIME-Version:Message-ID: Date:References:In-Reply-To:Subject:Cc:To:From:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=auvnPlCdrxbwfVCryOkTHE8CzjY0504gnLY8d2dRonQ=; b=fSyCifjmTxsHnkoflxwFQeSyAl mUUTEuogjrtzLCtv1mjuvQBOXj/0tid0MG7YohtTLOtxBsAM3Wnb8pCyCAk62V2wxQvncTNyTDx1M Va+rXomYJT6iR1QNrWUdB2IbGiQ8XGDF9955KRdQxk87KvObdw8vlMPU8Qo4BQikhJqQhyvqnlgQH Tx3CJuQUvVSy4teradOTmPhBIW35h+E9owCsbH6wYPFWO777J5pMXr1ddihzrl4ZyiBg0CN4yTrEp xNY49LzitVjiFDQyT3YQmjCSVBfix08tbop+0ToL74C+7bcDtsQPRNGmtWtOphfcLmRJkRTyX4ocn PJEGfqMQ==; Received: from galois.linutronix.de ([193.142.43.55]) by desiato.infradead.org with esmtps (Exim 4.96 #2 (Red Hat Linux)) id 1pwM8x-0067cU-2n; Tue, 09 May 2023 12:08:37 +0000 From: Thomas Gleixner DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1683634111; 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=auvnPlCdrxbwfVCryOkTHE8CzjY0504gnLY8d2dRonQ=; b=wafQfE3T818swYq6uLvh8KHiTe44B+AlTcCuev0YTvhSecK7fkanUUlrOFuq1HA2ASd8t+ BU6tHwwDMQA0mZaxMylheStrGpAitYQ7e4+1xdIBRK50qlGuPKGUbpzNoPFc/U7pFg4vp7 3txn/u3LsCuYBQ0eNUlaTm7ZlGVH1WlsNSZfP3xwKGSzwPqUJorHyzC7YM1MHYvCO7Lmx3 BiJQOvEs+Zr/r7cQvp3o3X/HSCezUruhmuDtMYKpw4lmxWL4y4XK9Xj0Ms0sscYlMfQk/M 8L9/ObIQjuOr/DXSdupvrplmykX+MkwMcI4Kqk1nxIkYGFdBkt+5ECVVyItbUg== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1683634111; 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=auvnPlCdrxbwfVCryOkTHE8CzjY0504gnLY8d2dRonQ=; b=iQxVDqhAuaPEJSQzwxbX/REaKwQ08dwCm2L5m3NrRVeFnmsUvKPu/IfGcUkN/jYTMsh6S3 yqlu1nzMP1/UIxCA== 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 14:08:31 +0200 Message-ID: <87mt2d1zcw.ffs@tglx> MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20230509_130836_100991_0982E182 X-CRM114-Status: GOOD ( 16.08 ) 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: > 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. As this is gone a few patches later, I just be lazy and leave it alone. _______________________________________________ linux-riscv mailing list linux-riscv@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-riscv